600 research outputs found

    Diversity, functional structure and functional redundancy of woodland plant communities: How do mixed tree species plantations compare with monocultures?

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    Managing forest plantation stands in a way that retains productivity targets, but that also fosters biodiversity and stand resilience are key sustainable forest management goals. Current forestry policy advocates a diversification of forest stands to achieve these goals, favouring mixed age structures and polycultures over single-aged monocultures. Evidence is lacking, however, to support this management recommendation for biodiversity gains and related ecosystem service delivery. We used indices of taxonomic diversity and functional structure to compare ground vegetation communities in mixed and pure stands of Scots pine (Pinus sylvestris) and pedunculate oak (Quercus robur) in each of three study regions. We categorised the 91 vascular plant species identified into functional effect and response groups. We tested the hypotheses that ground vegetation communities (i) differ significantly in structure and composition between Scots pine and oak monocultures and (ii) show enhanced levels of taxonomic and functional diversity and functional redundancy in mixed stands of Scots pine and oak compared with monocultures. We explored the implications of any differences in the functional structure of ground vegetation communities in the different stand types on two ecosystem services: nutrient availability and levels of resource provisioning for herbivores. Nine functional response groups (RG) and seven functional effect groups (EG) were identified with considerable overlap in the RG and EG species grouping. Three RGs had traits characteristic of forests (spring flowering herbs, tree saplings and shrubs/ climbers), one RG had traits characteristic of open habitats (annual ruderals) and the remaining RGs had more generalist traits (anemochorous perennials, graminoids and short perennials). No significant differences were found among stand types in terms of taxonomic diversity or richness of the different functional trait groups. Ground vegetation communities in the three study regions also had similar levels of functional redundancy across stand types. However, Scots pine and oak monocultures harboured significantly different abundances of species with distinct functional traits. In all three study regions, anemochorous perennials were significantly more abundant in Scots pine monocultures than oak monocultures, while two core forest groups (shrubs/ climbers, spring flowering herbs) were significantly more abundant in oak monocultures. Mixed stands had intermediate abundances of these functional groups. These differences have implications for the comparative availability of food resources and shelter for wildlife, but also the mobilisation and temporal availability of nutrients in the two monocultures. Thus, mixtures of Scots pine and pedunculate oak can temper significant tree species identity influences on ground vegetation functional diversity

    Dirac spinor fields in the teleparallel gravity: comment on "Metric-affine approach to teleparallel gravity"

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    We show that the coupling of a Dirac spinor field with the gravitational field in the teleparallel equivalent of general relativity is consistent. For an arbitrary SO(3,1) connection there are two possibilities for the coupling of the spinor field with the gravitational field. The problems of consistency raised by Y. N. Obukhov and J. G. Pereira in the paper {\it Metric-affine approach to teleparallel gravity} [gr-qc/0212080] take place only in the framework of one particular coupling. By adopting an alternative coupling the consistency problem disappears.Comment: 8 pages, Latex file, no figures, to appear in the Phys. Rev. D as a Commen

    Hydrocortisone inhibits prostaglandin production but not arachidonic acid release from cultured macrophages

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    AbstractWe have investigated the action of hydrocortisosone on arachidonic acid mobilisation in cultures of mouse peritoneal macrophages, mouse L929 cells and the mouse macrophage-like cell line RAW264. Hydrocortisone inhibits both arachidonic acid release and prostaglandin production by L929 cells. However, prostaglandin production by macrophages or RAW264 cells is inhibited with a concomitant stimulation rather than inhibition of arachidonic acid release. These data suggest that hydrocortisone acts at the level of phospholipase activity in fibroblasts but at a later stage of prostanoid production in macrophages

    Exclusionary employment in Britain’s broken labour market

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    There is growing evidence of the problematic nature of the UK’s ‘flexible labour market’ with rising levels of in-work poverty and insecurity. Yet successive Governments have stressed that paid work is the route to inclusion, focussing attention on the divide between employed and unemployed. Past efforts to measure social exclusion have tended to make the same distinction. The aim of this paper is to apply Levitas et al’s (2007) framework to assess levels of exclusionary employment, i.e. exclusion arising directly from an individual’s labour market situation. Using data from the Poverty and Social Exclusion UK survey, results show that one in three adults in paid work is in poverty, or in insecure or poor quality employment. One third of this group have not seen any progression in their labour market situation in the last five years. The policy focus needs to shift from ‘Broken Britain’ to Britain’s broken labour market

    The breakdown of the municipality as caring platform: lessons for co-design and co-learning in the age of platform capitalism

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    If municipalities were the caring platforms of the 19-20th century sharing economy, how does care manifest in civic structures of the current period? We consider how platforms - from the local initiatives of communities transforming neighbourhoods, to the city, in the form of the local authority - are involved, trusted and/or relied on in the design of shared services and amenities for the public good. We use contrasting cases of interaction between local government and civil society organisations in Sweden and the UK to explore trends in public service provision. We look at how care can manifest between state and citizens and at the roles that co-design and co-learning play in developing contextually sensitive opportunities for caring platforms. In this way, we seek to learn from platforms in transition about the importance of co-learning in political and structural contexts and make recommendations for the co-design of (digital) platforms to care with and for civil society

    Safety of direct oral anticoagulants in patients with hereditary hemorrhagic telangiectasia

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    Background: Hereditary haemorrhagic telangiectasia (HHT) is a rare vascular dysplasia resulting in visceral arteriovenous malformations and smaller mucocutaneous telangiectasia. Most patients experience recurrent nosebleeds and become anaemic without iron supplementation. However, thousands may require anticoagulation for conditions such as venous thromboembolismand/or atrial fibrillation. Over decades,tolerance data has been publishedfor almost 200HHT-affected usersof warfarinand heparins, but there are no publisheddata forthe newer direct oralanticoagulants(DOACs)in HHT. Methods: To provide such data, aretrospective audit was conducted across the eight HHT centres of the European Reference Network for Rare Vascular Disorders (VASCERN),in Denmark, France, Germany, Italy, Netherlands and UK. Results: Although HHT Centreshad not specifically recommended the use of DOACs, 32treatment episodes had been initiated by other cliniciansin 28patients reviewed at the centres, at median age 65years(range 30-84). Indications were for atrial fibrillation (16 treatment episodes) and venous thromboembolism (16 episodes).The 32 treatment episodes used Apixaban (n=15), Rivaroxaban (n=14), and Dabigatran (n=3). HHT nosebleeds increased in severity in 24/32 treatment episodes (75%), leading to treatment discontinuation in 11 (34.4%). Treatment discontinuation was required for 4/15(26.7%) Apixabanepisodes and 7/14 (50%)Rivaroxaban episodes.By a 4 point scale of increasing severity,there was a trend for Rivaroxaban to be associated with a greaterbleeding riskboth including and excluding patients who had used more than one agent (age-adjusted coefficients 0.61 (95% confidence intervals 0.11, 1.20) and 0.74 (95% confidence intervals 0.12, 1.36) respectively. Associationswere maintained after adjustment for genderand treatment indication. Extreme haemorrhagic responses, worse thananything experienced previously, with individual nosebleedslasting hours requiring hospital admissions, blood transfusions and in all cases treatment discontinuation, occurred in5/14(35.7%) Rivaroxabanepisodes compared to 3/15(20%) Apixabanepisodes and published rates of ~5% for warfarin and heparin. Conclusions: Currently, conventional heparin and warfarin remain first choice anticoagulantsin HHT. If newer anticoagulants are considered,although study numbers are small, at this stage Apixaban appearsto be associated with lesser bleeding riskthan Rivaroxaban

    Using a realist approach to evaluate smoking cessation interventions targeting pregnant women and young people

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    Background This paper describes a study protocol designed to evaluate a programme of smoking cessation interventions targeting pregnant women and young people living in urban and rural locations in Northeast Scotland. The study design was developed on so-called 'realist' evaluation principles, which are concerned with the implementation of interventions as well as their outcomes. Methods/design A two-phased study was designed based on the Theory of Change (TOC) using mixed methods to assess both process and outcome factors. The study was designed with input from the relevant stakeholders. The mixed-methods approach consists of semi-structured interviews with planners, service providers, service users and non-users. These qualitative interviews will be analysed using a thematic framework approach. The quantitative element of the study will include the analysis of routinely collected data and specific project monitoring data, such as data on service engagement, service use, quit rates and changes in smoking status. Discussion The process of involving key stakeholders was conducted using logic modelling and TOC tools. Engaging stakeholders, including those responsible for funding, developing and delivering, and those intended to benefit from interventions aimed at them, in their evaluation design, are considered by many to increase the validity and rigour of the subsequent evidence generated. This study is intended to determine not only the components and processes, but also the possible effectiveness of this set of health interventions, and contribute to the evidence base about smoking cessation interventions aimed at priority groups in Scotland. It is also anticipated that this study will contribute to the ongoing debate about the role and challenges of 'realist' evaluation approaches in general, and the utility of logic modelling and TOC approaches in particular, for evaluation of complex health interventions

    Teleparallel formalism of galilean gravity

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    A pseudo-Riemannian manifold is introduced, with light-cone coordinates in (4+1) dimensional space-time, to describe a Galilei covariant gravity. The notion of 5-bein and torsion are developed and a galilean version of teleparallelism is constructed in this manifold. The formalism is applied to two spherically symmetric configurations. The first one is an ansatz which is inferred by following the Schwarzschild solution in general relativity. The second one is a solution of galilean covariant equations. In addition, this Galilei teleparallel approach provides a prescription to couple the 5-bein field to the galilean covariant Dirac field.Comment: 10 page

    Lung abscess predicts the surgical outcome in patients with pleural empyema

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    <p>Abstract</p> <p>Objectives</p> <p>Most cases of pleural empyema are caused by pulmonary infections, which are usually combined with pneumonia or lung abscess. The mortality of patients with pleural empyema remains high (up to 20%). It also contributes to higher hospital costs and longer hospital stays. We studied pleural empyema with combined lung abscess to determine if abscess was associated with mortality.</p> <p>Methods</p> <p>From January 2004 to December 2006, we retrospectively reviewed 259 patients diagnosed with pleural empyema who received thoracscopic decortications of the pleura in a single medical center. We evaluated their clinical data and analyzed their chest computed tomography scans. Outcomes of pleural empyema were compared between groups with and without lung abscess.</p> <p>Results</p> <p>Twenty-two pleural empyema patients had lung abscesses. Clinical data showed significantly higher incidences in the lung abscess group of pre-operative leukocytosis, need for an intensive care unit stay and mortality.</p> <p>Conclusion</p> <p>Patients with pleural empyema and lung abscess have higher intensive care unit admission rate, higher mortality during 30 days and overall mortality than patients with pleural empyema. The odds ratio of lung abscess is 4.685. Physician shall pay more attention on high risk patient of lung abscess for early detection and management.</p
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