841 research outputs found

    Peatlands and Climate Change

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    This is the author's manuscript version and this version is free to view and download for personal use only. Not for re-distribution, re-sale or use in derivative works.This material is forthcoming in Peatland Restoration and Ecosystem Services Science, Policy and Practice, 9781107619708, © Cambridge University PressThe fundamental reason for the presence of peatlands is a positive balance between plant production and decomposition. Organic matter accumulates in these systems because prolonged waterlogged conditions result in soil anoxia (i.e., exclusion of oxygen), and under these conditions decomposition rates can be lower than those of primary production. Climate therefore plays an important role in peat accumulation, both directly by affecting productivity and decomposition processes, and indirectly through its effects on hydrology/water balance and vegetation (for a summary, refer to Yu, Beilman & Jones 2009). Climate provides broad-scale constraints or controls on peatland extent, types and vegetation, and ultimately, ecosystem functioning, carbon accumulation, greenhouse gas exchange and all of the other ecosystem services that peatlands provide. Peatlands can play a vital role in helping society mitigate and adapt to climate change, because of their carbon and water regulating functions, while at the same time, the climate sensitivity of peatlands makes them potentially vulnerable to future global warming and changes in spatial and temporal patterns of precipitation, especially if they are in a degraded state. Climate change is likely to alter the hydrology and soil temperature of peatlands, with far- reaching consequences for their biodiversity, ecology and biogeochemistry. Their involvement in the global carbon cycle will also be affected, with the possibility of drier conditions allowing peatland erosion and increases in CO2 emissions that would result in a positive feedback to climate change (Turetsky 2010). This highlights all the more the need for restoration to ensure peatlands are resilient to change so that they continue to deliver ecosystem services for human well-being. This chapter describes the interactions between climate and peatlands, in three sections. The first section explains how present climate influences peatlands, by documenting how climate limits peatland geographical extent globally, and how bioclimatic envelope models can predict peatland extent. We indicate how each type of peatland is linked to a specific climate range, and introduce the concept of ecosystem function in relation to climate. The second section looks into the past. It describes how peat preserves a record of past climates and environmental conditions that can be deciphered to reveal the history of peatland vegetation, hydrology and carbon accumulation changes in relation to past changes in climate. We highlight lessons that can be learned from the palaeorecord preserved in peat. The final section discusses the potential effects of present and future climate change on peatlands, their extent, carbon accumulation rates, fire frequency, water table and greenhouse gas exchanges. We also consider how increases in sea level and CO2 concentration, and decreases in the extent of permafrost, are likely to affect peatlands

    Corrigendum: Solar cycles or random processes? Evaluating solar variability in Holocene climate records

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    This is the final version of the article. Available from Springer Nature via the DOI in this record.The article to which this is the corrigendum is in ORE at http://hdl.handle.net/10871/21766A coding error in the Monte Carlo procedure for the determination of critical values in running correlation analysis (presented in Supplementary Data S8) has been brought to the attention of the authors.[...

    Association between pain intensity and depressive symptoms in community-dwelling adults: longitudinal findings from the Survey of Health, Ageing and Retirement in Europe (SHARE)

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    Purpose: To investigate the longitudinal associations between pain and depressive symptoms in adults. Methods: Prospective cohort study on data from 28,515 community-dwelling adults ≥ 50 years, free from depression at baseline (Wave 5), with follow-up in Wave 6 of the Survey of Health, Ageing and Retirement in Europe (SHARE). Significant depressive symptoms were defined by a EURO-D score ≥ 4. The longitudinal association between baseline pain intensity and significant depressive symptoms at follow-up was analysed using logistic regression models; odds ratios (ORs) and confidence intervals (CI) were calculated, adjusting for socio-demographic and clinical factors, physical inactivity, loneliness, mobility and functional impairments. Results: Mean age was 65.4 years (standard deviation 9.0, range 50–99); 14,360 (50.4%) participants were women. Mean follow-up was 23.4 (standard deviation 3.4) months. At baseline, 2803 (9.8%) participants reported mild pain, 5253 (18.4%) moderate pain and 1431 (5.0%) severe pain. At follow-up, 3868 (13.6%) participants—1451 (10.3%) men and 2417 (16.8%) women—reported significant depressive symptoms. After adjustment, mild, moderate and severe baseline pain, versus no pain, were associated with an increased likelihood of significant depressive symptoms at follow-up: ORs (95% CI) were 1.20 (1.06–1.35), 1.32 (1.20–1.46) and 1.39 (1.19–1.63), respectively. These associations were more pronounced in men compared to women, and consistent in participants aged 50–64 years, those without mobility or functional impairment, and those without loneliness at baseline. Conclusion: Higher baseline pain intensity was longitudinally associated with a greater risk of significant depressive symptoms at 2-year follow-up, in community-dwelling adults without baseline depression

    Investigating local policy drivers for alcohol harm prevention: a comparative case study of two local authorities in England

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    Background: The considerable challenges associated with implementing national level alcohol policies have encouraged a renewed focus on the prospects for local-level policies in the UK and elsewhere. We adopted a case study approach to identify the major characteristics and drivers of differences in the patterns of local alcohol policies and services in two contrasting local authority (LA) areas in England. Methods: Data were collected via thirteen semi-structured interviews with key informants (including public health, licensing and trading standards) and documentary analysis, including harm reduction strategies and statements of licensing policy. A two-stage thematic analysis was used to categorize all relevant statements into seven over-arching themes, by which document sources were then also analysed. Results: Three of the seven over-arching themes (drink environment, treatment services and barriers and facilitators), provided for the most explanatory detail informing the contrasting policy responses of the two LAs: LA1 pursued a risk-informed strategy via a specialist police team working proactively with problem premises and screening systematically to identify riskier drinking. LA2 adopted a more upstream regulatory approach around restrictions on availability with less emphasis on co-ordinated screening and treatment measures. Conclusion: New powers over alcohol policy for LAs in England can produce markedly different policies for reducing alcohol-related harm. These difference are rooted in economic, opportunistic, organisational and personnel factors particular to the LAs themselves and may lead to closely tailored solutions in some policy areas and poorer co-ordination and attention in others

    Factors affecting the intention of providers to deliver more effective continuing medical education to general practitioners: a pilot study

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    BACKGROUND: Despite the importance of continuing medical education (CME) for GPs, there has been little research into how providers decide what types of CME to deliver to GPs. This study aimed to identify factors affecting the intention of providers to provide more effective types of CME; and to design a survey instrument which can be used to test the applicability of Triandis' model of social behaviour to the provision of CME to general practitioners. METHODS: This was a cross-sectional study on a convenience sample of 11 Australian providers of CME for interviews and a random sample of 25 providers for the pilot test. Open-ended interviews structured on Triandis' theory were performed with key informants who provide CME to GPs. These were used to develop a pilot survey instrument to measure the factors affecting intention, resulting in a revised instrument for use in further research. RESULTS: There was a broad range of factors affecting providers' intention to deliver more effective forms of CME identified, and these were classifiable in a manner which was consistent with Triandis' model. Key factors affecting providers' intention were the attitude toward CME within organisations and the time and extra work involved. CONCLUSIONS: We identified a range of potential factors influencing the intention of providers to provide more effective forms of CME, in all categories of Triandis model. Those interested in increasing the choice of more effective CME activities available to GPs may need to broaden the methods used in working with providers to influence them to use more effective CME techniques. The interview material and questionnaire analysis of the pilot survey support the use of Triandis model. Further research is needed to validate Triandis'model for the intention to deliver more effective forms of CME. Such research will inform future strategies aimed at increasing the amount and choice of effective CME activities available for GPs

    Potential implications of differential preservation of testate amoeba shells for paleoenvironmental reconstruction in peatlands

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    Testate amoebae are now commonly used in paleoenvironmental studies but little is known of their taphonomy. There is some experimental evidence for differential preservation of some testate amoeba shell types over others, but it is unclear what, if any impact this has on palaeoenvironmental reconstruction. To investigate this issue we looked at palaeoecological evidence for the preservation of different shell types. We then investigated the possible impact of selective preservation on quantitative palaeoenvironmental inference. We first used existing palaeoecological data sets to assess the vertical patterns of relative abundance in four testate amoeba shell types: (1) shells made of secreted biosilica plates (idiosomes, e.g. Euglypha), (2) idiosomes with thick organic coating (Assulina), (3) proteinaceous shells (e.g. Hyalosphenia), (4) shells built from recycled organic or mineral particles (xenosomes) (e.g. Difflugia, Centropyxis). In three diagrams a clear pattern of decay was only observed for the idiosome type. In order to assess the implications of differential preservation of testate amoeba taxa for paleoenvironmental reconstruction we then carried out simulations using three existing transfer functions and a wide range of scenarios, downweighting different test categories to represent the impact of selective test decomposition. Simulation results showed that downweighting generally reduced overall model performance. However downweighting a shell type only produced a consistent directional bias in inferred water table depth where that shell type is both dominant and shows a clear preference along the ecological gradient. Applying a scenario derived from previous experimental work did not lead to significant difference in inferred water table. Our results show that differential shell preservation has little impact on paleohydrological reconstruction from Sphagnum-dominated peatlands. By contrast, for the minerotrophic peatlands data-set loss of idiosome tests leads to consistent underestimation of water table depth. However there are few studies from fens and it is possible that idiosome tests are not always dominant, and/or that differential decomposition is less marked than in Sphagnum peatlands. Further work is clearly needed to assess the potential of testate amoebae for paleoecological studies of minerotrophic peatlands

    Focusing and Compression of Ultrashort Pulses through Scattering Media

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    Light scattering in inhomogeneous media induces wavefront distortions which pose an inherent limitation in many optical applications. Examples range from microscopy and nanosurgery to astronomy. In recent years, ongoing efforts have made the correction of spatial distortions possible by wavefront shaping techniques. However, when ultrashort pulses are employed scattering induces temporal distortions which hinder their use in nonlinear processes such as in multiphoton microscopy and quantum control experiments. Here we show that correction of both spatial and temporal distortions can be attained by manipulating only the spatial degrees of freedom of the incident wavefront. Moreover, by optimizing a nonlinear signal the refocused pulse can be shorter than the input pulse. We demonstrate focusing of 100fs pulses through a 1mm thick brain tissue, and 1000-fold enhancement of a localized two-photon fluorescence signal. Our results open up new possibilities for optical manipulation and nonlinear imaging in scattering media

    The effectiveness of lunchbox interventions on improving the foods and beverages packed and consumed by children at centre-based care or school: a systematic review and meta-analysis

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    Objective: To assess the effectiveness of lunchbox interventions aiming to improve the foods and beverages packed and consumed by children at centre-based care or school; and subsequent impact on children’s adiposity. Methods: Systematic search of nine databases for controlled trials published in English between 1995-January 2017. Where appropriate, data were pooled in a random effects meta-analysis. Results: Of the 1601 articles identified, ten studies (centre-based care n = 4, school n = 6) were included of which eight were RCTs. The impact of interventions on the packing of discretionary foods, sugar-sweetened drinks and other core foods was inconsistent. Meta-analysis of four RCTs trials found a moderate increase in provision of vegetables (SMD = 0.40 95% CI 0.16 to 0.64, p = 0.001, I2 = 82%; equivalent to a mean difference of 0.28 serves) but not fruit. Four studies reported impact on children’s dietary intake, one reported no significant effect on consumption of discretionary foods, one reported improvements in the consumption of sugar-sweetened drinks and water, and two reported improvements in consumption of vegetables and fruit. Two studies, that were broader obesity prevention interventions, reported no significant impact on adiposity. Conclusions: There is some evidence that lunchbox interventions are effective in improving the packing of vegetables in children’s lunchboxes, however more robust research is required to determine the impact on children’s dietary intake and adiposity. Trial registration: PROSPERO 2016: CRD4201603564
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