252 research outputs found

    Peatland initiation and carbon accumulation in the Falkland Islands

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    The Falkland Islands in the South Atlantic Ocean contain extensive peatlands at the edge of their global climatic envelope, but the long-term carbon dynamics of these sites is poorly quantified. We present new data for ten sites, compile previously-published data and produce a new synthesis. Many peatlands in the Falkland Islands developed notably early, with a fifth of basal 14 C dates pre-Holocene. Falkland Islands peats have high ash content, high carbon content and high bulk density compared to global norms. In many sites carbon accumulation rates are extremely low, which may partly relate to low average rainfall, or to carbon loss through burning and aeolian processes. However, in coastal Tussac peatlands carbon accumulation can be extremely rapid. Our re-analysis of published data from Beauchene Island, the southernmost of the Falkland Islands, yields an exceptional long-term apparent carbon accumulation rate of 139 g C m −2 yr −1 , to our knowledge the highest recorded for any global peatland. This high accumulation might relate to the combination of a long growing-season and marine nutrient inputs. Given extensive coverage and carbon-dense peats the carbon stock of Falkland Islands peatlands is clearly considerable but robust quantification will require the development of a reliable peat map. Falkland Island peatlands challenge many standard assumptions and deserve more detailed study

    From primed construct to motivated behavior: validation processes in goal pursuit

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    When posting or re-using the article, you should provide a link/URL from the article posted to the SAGE Journals Online site where the article is published: http://online.sagepub.com and please make the following acknowledgment: "The final, definitive version of this paper has been published in , Vol/Issue, Month/Year by SAGE Publications Ltd, All rights reserved. © [The Author(s)]"Past research has found that primes can automatically initiate unconscious goal striving. Recent models of priming have suggested that this effect can be moderated by validation processes. According to a goal-validation perspective, primes should cause changes in one’s motivational state to the extent people have confidence in the prime-related mental content. Across three experiments, we provided the first direct empirical evidence for this goal-validation account. Using a variety of goal priming manipulations (cooperation vs. competition, achievement, and self-improvement vs. saving money) and validity inductions (power, ease, and writing about confidence), we demonstrated that the impact of goal primes on behavior occurs to a greater extent when conditions foster confidence (vs. doubt) in mental contents. Indeed, when conditions foster doubt, goal priming effects are eliminated or counter to the implications of the prime. The implications of these findings for research on goal priming and validation processes are discussed.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported in part by NSF Grant BCS-0847834 (to R.E.P.) and by Spanish grant PSI2011-26212 (to P.B.)

    Role of Serum Biomarkers in Early Detection of Diabetic Cardiomyopathy in the West Virginian Population

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    Objectives: Diabetic cardiomyopathy (DCM) is an established complication of diabetes mellitus. In West Virginia, the especially high incidence of diabetes and heart failure validate the necessity of developing new strategies for earlier detection of DCM. Since most DCM patients remain asymptomatic until the later stages of the disease when the fibrotic complications become irreversible, we aimed to explore biomarkers that can identify early-stage DCM. Methods: The patients were grouped into 4 categories based on clinical diabetic and cardiac parameters: Control, Diabetes (DM), Diastolic dysfunction (DD), and Diabetes with diastolic dysfunction (DM+DD), the last group being the preclinical DCM group. Results: Echocardiography images indicated severe diastolic dysfunction in patients with DD+DM and DD compared to DM or control patients. In the DM and DM+DD groups, TNFα, isoprostane, and leptin were elevated compared to control (p\u3c0.05), as were clinical markers HDL, glucose and hemoglobin A1C. Fibrotic markers IGFBP7 and TGF-ÎČ followed the same trend. The Control group showed higher beneficial levels of adiponectin and bilirubin, which were reduced in the DM and DM+DD groups (p\u3c0.05). Conclusion: The results from our study support the clinical application of biomarkers in diagnosing early stage DCM, which will enable attenuation of disease progression prior to the onset of irreversible complications

    Can on-site management mitigate nitrogen deposition impacts in non-wooded habitats?

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    Nitrogen (N) deposition is a major cause of plant biodiversity loss, with serious implications for appropriate management of protected sites. Reducing N emissions is the only long-term solution. However, on-site management has the potential to mitigate some of the adverse effects of N deposition. In this paper we review how management activities such as grazing, cutting, burning, hydrological management and soil disturbance measures can mitigate the negative impacts of N across a range of temperate habitats (acid, calcareous and neutral grasslands, sand dunes and other coastal habitats, heathlands, bogs and fens). The review focuses mainly on European habitats, which have a long history of N deposition, and it excludes forested systems. For each management type we distinguish between actions that improve habitat suitability for plant species of conservation importance, and actions that immobilize N or remove it from the system. For grasslands and heathlands we collate data on the quantity of N removal by each management type. Our findings show that while most activities improve habitat suitability, the majority do little to slow or to reduce the amount of N accumulating in soil pools at current deposition rates. Only heavy cutting/mowing with removal in grasslands, high intensity burns in heathlands and sod cutting remove more N than comes in from deposition under typical management cycles. We conclude by discussing some of the unintended consequences of managing specifically for N impacts, which can include damage to non-target species, alteration of soil processes, loss of the seedbank and loss of soil carbon

    Studies of group velocity reduction and pulse regeneration with and without the adiabatic approximation

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    We present a detailed semiclassical study on the propagation of a pair of optical fields in resonant media with and without adiabatic approximation. In the case of near and on resonance excitation, we show detailed calculation, both analytically and numerically, on the extremely slowly propagating probe pulse and the subsequent regeneration of a pulse via a coupling laser. Further discussions on the adiabatic approximation provide many subtle understandings of the process including the effect on the band width of the regenerated optical field. Indeed, all features of the optical pulse regeneration and most of the intricate details of the process can be obtained with the present treatment without invoke a full field theoretical method. For very far off resonance excitation, we show that the analytical solution is nearly detuning independent, a surprising result that is vigorously tested and compared to numerical calculations with very good agreement.Comment: 13 pages, 15 figures, submitted to Phys. Rev.

    Electronic structure of superconducting graphite intercalate compounds: The role of the interlayer state

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    Although not an intrinsic superconductor, it has been long--known that, when intercalated with certain dopants, graphite is capable of exhibiting superconductivity. Of the family of graphite--based materials which are known to superconduct, perhaps the most well--studied are the alkali metal--graphite intercalation compounds (GIC) and, of these, the most easily fabricated is the C8{}_8K system which exhibits a transition temperature Tc≃0.14\bm{T_c\simeq 0.14} K. By increasing the alkali metal concentration (through high pressure fabrication techniques), the transition temperature has been shown to increase to as much as 5\bm 5 K in C2{}_2Na. Lately, in an important recent development, Weller \emph{et al.} have shown that, at ambient conditions, the intercalated compounds \cyb and \cca exhibit superconductivity with transition temperatures Tc≃6.5\bm{T_c\simeq 6.5} K and 11.5\bm{11.5} K respectively, in excess of that presently reported for other graphite--based compounds. We explore the architecture of the states near the Fermi level and identify characteristics of the electronic band structure generic to GICs. As expected, we find that charge transfer from the intercalant atoms to the graphene sheets results in the occupation of the π\bm\pi--bands. Yet, remarkably, in all those -- and only those -- compounds that superconduct, we find that an interlayer state, which is well separated from the carbon sheets, also becomes occupied. We show that the energy of the interlayer band is controlled by a combination of its occupancy and the separation between the carbon layers.Comment: 4 Figures. Please see accompanying experimental manuscript "Superconductivity in the Intercalated Graphite Compounds C6Yb and C6Ca" by Weller et a

    A New High-Resolution Map of World Mountains and an Online Tool for Visualizing and Comparing

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    Answers to the seemingly straightforward questions “what is a mountain?” and “where are the mountains of the world?” are in fact quite complex, and there have been few attempts to map the mountains of the earth in a consistent and rigorous fashion. However, knowing exactly where mountain ecosystems are distributed on the planet is a precursor to conserving them, as called for in Sustainable Development Goals 6 and 15 of the United Nations 2030 Agenda for Sustainable Development. In this article we first compare 3 characterizations of global mountain distributions, including a new, high-resolution (250 m) map of global mountains derived from terrain characteristics. We show how differences in conceptual definition, methodology, and spatial resolution of source data can result in differences in the extent and location of lands classed as mountains. For example, the new 250-m resource documents a larger global mountain extent than previous characterizations, although it excludes plateaus, hilly forelands, and other landforms that are often considered part of mountain areas. We then introduce the Global Mountain Explorer, a new web-based application specifically developed for exploration, visualization, and comparison of these maps. This new open-access tool is an intuitive and versatile resource suitable for a broad range of users and applications

    Complete Genome Sequences of Paenibacillus Larvae Phages BN12, Dragolir, Kiel007, Leyra, Likha, Pagassa, PBL1c, and Tadhana

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    We present here the complete genomes of eight phages that infect Paenibacillus larvae, the causative agent of American foulbrood in honeybees. Phage PBL1c was originally isolated in 1984 from a P. larvae lysogen, while the remaining phages were isolated in 2014 from bee debris, honeycomb, and lysogens from three states in the USA
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