29 research outputs found

    Synthesis

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    Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the level of pollution that would be harmful to ecosystems is the critical loads approach. The critical load is dei ned as the level of a pollutant below which no detrimental ecological effect occurs over the long term according to present knowledge. The objective of this project was to synthesize current research relating atmospheric N deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The receptors that we evaluated included freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical, and (2) individual species, population, and community responses. This report synthesizes current research relating atmospheric nitrogen (N) deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The report evaluates the following receptors: freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical; and (2) individual species, population, and community responses. The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1 to 39 kg N ha-1 y-1. This range spans the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, trees

    Synthesis

    Get PDF
    Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the level of pollution that would be harmful to ecosystems is the critical loads approach. The critical load is dei ned as the level of a pollutant below which no detrimental ecological effect occurs over the long term according to present knowledge. The objective of this project was to synthesize current research relating atmospheric N deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The receptors that we evaluated included freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical, and (2) individual species, population, and community responses. This report synthesizes current research relating atmospheric nitrogen (N) deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The report evaluates the following receptors: freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical; and (2) individual species, population, and community responses. The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1 to 39 kg N ha-1 y-1. This range spans the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, trees

    Meta-Analysis Comparing Different Behavioral Treatments for Late-Life Anxiety

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    OBJECTIVE: To evaluate the efficacy of different types of behavioral treatments for geriatric anxiety [cognitive-behavioral therapy (CBT) alone, CBT with relaxation training (RT), and RT alone]. METHOD: We compared effect sizes from 19 trials. Analyses were based on uncontrolled outcomes (comparing post-treatment and pre-treatment scores) and effects relative to control conditions on both anxiety and depressive symptoms. RESULTS: Treatments for older adults with anxiety symptoms were, on average, more effective than active control conditions. Effect sizes were comparable to those reported elsewhere for CBT for anxiety in the general population or for pharmacotherapy in anxious older adults. CBT (alone or augmented with RT) does not appear to add anything beyond RT alone, although a direct comparison is challenging given differences in control conditions. Effects on depressive symptoms were smaller, with no differences among treatment types. CONCLUSION: Results suggest that behavioral treatments are effective for older adults with anxiety disorders and symptoms. Results must be interpreted with caution given the limitations of the literature, including differing sample characteristics and control conditions across studies

    Underusers of mammogram screening: stage of adoption in five U.S. subpopulations. The NCI Breast Cancer Screening Consortium

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    BACKGROUND: The purpose of this report is to describe the characteristics of women ages 50 to 80 who do not follow commonly accepted mammography screening guidelines. It provides unique understanding of the robustness of characteristics of underusers across five different U.S. subpopulations. METHODS: The data are from the baseline surveys of the five studies of the NCI Breast Cancer Screening Consortium. Stage of adoption of mammography screening and other characteristics of underusers are presented. Polytomous logistic regression analysis was used to explore multivariable associations with stage of adoption in each study site. RESULTS: The five samples studied by the Consortium range in size from 259 to 4,477 women (n = 11,292). The relationship of the perceptions of the pros and cons of mammography with stage of adoption was strikingly similar across the five samples. Other variables consistently associated with stage were a recent receipt of a breast physical examination and recommendation for mammography by a physician. CONCLUSIONS: The findings suggest a need to encourage regular screening through effective communication from a health care provider. Intervention messages should be designed to increase the pros of mammography, decrease the cons, and highlight these differentially according to the woman\u27s stage of adoption

    Extended Family Outreach in Hereditary Cancer Using Web-Based Genealogy, Direct-to-Consumer Ancestry Genetics, and Social Media: Mixed Methods Process Evaluation of the ConnectMyVariant Intervention

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    BackgroundCascade screening, defined as helping at-risk relatives get targeted genetic testing of familial variants for dominant hereditary cancer syndromes, is a proven component of cancer prevention; however, its uptake is low. We developed and conducted a pilot study of the ConnectMyVariant intervention, in which participants received support to contact at-risk relatives that extended beyond first-degree relatives and encourage relatives to obtain genetic testing and connect with others having the same variant through email and social media. The support that participants received included listening to participants’ needs, assisting with documentary genealogy to find common ancestors, facilitating direct-to-consumer DNA testing and interpretation, and assisting with database searches. ObjectiveWe aimed to assess intervention feasibility, motivations for participating, and engagement among ConnectMyVariant participants and their families. MethodsWe used a mixed methods design including both quantitative and qualitative evaluation methods. First, we considered intervention feasibility by characterizing recruitment and retention using multiple recruitment mechanisms, including web-based advertising, dissemination of invitations with positive test results, provider recruitment, snowball sampling, and recruitment through web-based social networks and research studies. Second, we characterized participants’ motivations, concerns, and engagement through project documentation of participant engagement in outreach activities and qualitative analysis of participant communications. We used an inductive qualitative data analysis approach to analyze emails, free-text notes, and other communications generated with participants as part of the ConnectMyVariant intervention. ResultsWe identified 84 prospective participants using different recruitment mechanisms; 57 participants were ultimately enrolled in the study for varying lengths of time. With respect to motivations for engaging in the intervention, participants were most interested in activities relating to genealogy and communication with others who had their specific variants. Although there was a desire to find others with the same variant and prevent cancer, more participants expressed an interest in learning about their genealogy and family health history, with prevention in relatives considered a natural side effect of outreach. Concerns about participation included whether relatives would be open to communication, how to go about it, and whether others with a specific variant would be motivated to help find common ancestors. We observed that ConnectMyVariant participants engaged in 6 primary activities to identify and communicate with at-risk relatives: sharing family history, family member testing, direct-to-consumer genealogy genetic testing analysis, contacting (distant) relatives, documentary genealogy, and expanding variant groups or outreach. Participants who connected with others who had the same variant were more likely to engage with several extended family outreach activities. ConclusionsThis study demonstrated that there is an interest in extended family outreach as a mechanism to improve cascade screening for hereditary cancer prevention. Additional research to systematically evaluate the outcomes of such outreach may be challenging but is warranted
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