59 resultados para 20-GC 2


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Recent experiments undertaken at the Rutherford Appleton Laboratory to produce X-ray lasing over the 5-30 nm wavelength range are reviewed. The efficiency of lasing is optimized when the main pumping pulse interacts with a preformed plasma. Experiments using double 75-ps pulses and picosecond pulses superimposed on 300-ps background pulses are described. The use of travelling wave pumping with the approximately picosecond pulse experiments is necessary as the gain duration becomes comparable to the time for the X-ray laser pulse to propagate along the target length. Results from a model taking account of laser saturation and deviations from the speed of light c of the travelling wave and X-ray laser group velocity are presented. We show that X-ray laser pulses as short as 2-3 ps can be produced with optical pumping pulses of approximate to1-ps.

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This paper examines the degree to which tree-associated Coleoptera (beetles) and pollen could be used to predict the degree of ‘openness’ in woodland. The results from two modern insect and pollen analogue studies from ponds at Dunham Massey, Cheshire and Epping Forest, Greater London are presented. We explore the reliability of modern pollen rain and sub-fossil beetle assemblages to represent varying degrees of canopy cover for up to 1000m from a sampling site. Modern woodland canopy structure around the study sites has been assessed using GIS-based mapping at increasing radial distances as an independent check on the modern insect and pollen data sets. These preliminary results suggest that it is possible to use tree-associated Coleoptera to assess the degree of local vegetation openness. Additionally, it appears that insect remains may indicate the relative intensity of land use by grazing animals. Our results also suggest most insects are collected from within a 100m to 200m radius of the sampling site. The pollen results suggest that local vegetation and density of woodland in the immediate area of the sampling site can have a strong role in determining the pollen signal.

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Previous studies have shown that in vitro adenosine enhances histamine release from activated human lung mast cells obtained by enzymic dispersion of lung parenchyma. However, adenosine alone has no effect on histamine release from these cells. Given the evidence for direct activation of mast cells after endobronchial challenge with adenosine and previous studies indicating that mast cells obtained at bronchoalveolar lavage are a better model for asthma studies than those obtained by enzymic dispersion of lung tissue, the histamine-releasing effect of adenosine was examined on lavage mast cells. Bronchoalveolar lavage fluid was obtained from patients attending hospital for routine bronchoscopy (n = 54). Lavage cells were challenged with adenosine or adenosine receptor agonists (20 min, 37 degrees C) and histamine release determined using an automated fluorometric assay. Endogenous adenosine levels were also measured in lavage fluid (n = 9) via an HPLC method. Adenosine alone caused histamine release from ravage mast cells in 37 of 54 patients with a maximal histamine release of 20.56 +/- 2.52% (range 5.2-61 %). The adenosine receptor agonists (R)-N-6-(2-phenylisopropyl)adenosine, 5'-N-ethylcarboxamido-adenosine and CGS21680 also induced histamine release from lavage mast cells. Preincubation of lavage mast cells with the adenosine receptor antagonist xanthine amine congener caused significant inhibition of the response to adenosine (P = 0.007). There was an inverse correlation between endogenous adenosine levels in the lavage fluid and the maximal response to in vitro adenosine challenge of the lavage cells. The findings of the present study indicate a means by which adenosine challenge of the airways can induce bronchoconstriction and support a role for adenosine in the pathophysiology of asthma. The results also suggest that cells obtained from bronchoalveolar ravage fluid may provide the ideal model for the testing of novel, adenosine receptor, targeted therapies for asthma.

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Irreversible tissue damage within the cystic fibrosis (CF) lung is mediated by proteolytic enzymes during an inflammatory response. Serine proteinases, in particular neutrophil elastase (NE), have been implicated however, members of the cysteine proteinase family may also be involved. The aim of this study was to determine cathepsin B and S levels in cystic fibrosis (CF) sputum and to assess any relationship to recognized markers of inflammation such as sputum NE, interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-a), urine TNF receptor 1 (TNFr1), plasma IL-6, and serum C-reactive protein (CRP). Proteinase activities were measured in the sputum of 36 clinically stable CF patients using spectrophotometric and fluorogenic assays. Immunoblots were also used to confirm enzyme activity data. All other parameters were measured by ELISA. Patients had a mean age of 27.2 (8.2) years, FEV. of 1.6 (0.79) L and BMI of 20.7 (2.8). Both cathepsin B and S activities were detected in all samples, with mean concentrations of 18.0 (13.5)?µg/ml and 1.6 (0.88)?µg/ml, respectively and were found to correlate not only with each other but with NE, TNF-a and IL-8 (in all cases .?<?0.05). Airway cathepsin B further correlated with circulatory IL-6 and CRP however, no relationship for either cathepsin was observed with urine TNFr1. This data indicates that cathepsin B and S may have important roles in the pathophysiology of CF lung disease and could have potential as markers of inflammation in future studies. Pediatr. Pulmonol. 2010; 45:860–868.

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Objectives: Much has been written about the costs and cost-effectiveness of community care for people with learning disabilities resettled from long stay hospital care. However, comparatively little has been published about the cost of hospital services relating to the preparatory process before eventual resettlement and the disengagement of formal, sustained input from hospital staff. This study describes and costs the input provided by a hospital based multi-disciplinary team into the resettlement of adults with learning disabilities, from long stay wards in Muckamore Abbey Hospital in Northern Ireland between 1996 and 1999 (n = 71).

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An increasing amount of attention is being given to the use of human rights measurement indicators in monitoring ‘progress’ in rights and there is consequently a growing focus on statistics and information. This article concentrates on the use of statistics in rights discourse, with reference to the new human rights institution for the European Union: the Fundamental Rights Agency. The article has two main objectives: first, to show that statistics operate as technologies of governmentality – by explaining that statistics both govern rights and govern through rights. Second, the article discusses the implications that this has for rights discourse – rights become a discourse of governmentality, that is a normalizing and regulating discourse. In doing so, the article stresses the importance of critique and questioning new socio-legal methodologies, which involve the collection and dissemination of information and data (statistics), in rights discourse.

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This study considers the possibility of auditing students’ ethical judgment being affected by two factors, namely ethical orientation and gender. While tests revealed that more idealistic students judged some unethical situations more strictly than less idealistic students, overall no significant relationship was found between ethical orientation and ethical judgment. The study also reported no significant relationship between gender and ethical judgment. Furthermore, males were as likely as females to be classified as high idealists. Overall, the findings from the current study inform auditing educators that discriminating among students on the basis of ethical orientation and gender may not assist in stimulating students’ discussion and resolution of ethical dilemmas.

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This article explores the nature of surrogate consumption activity with three cases of non-institutionalised home confined consumers. The role played by personal communities in their daily lives is explored from the constrained rural contexts in which they consume. Despite the barriers to achieving normalcy in the marketplace, home confined consumers are able to realise freedom and agency, and express identity through engagement in surrogate consumption activity. Surrogate consumption activity also provides home confined consumers with opportunities to reinforce and challenge traditional family practices (discourses of care) through the ability for relationship culture development and social capital creation. Findings in this study show that home confined consumers, labeled as 'limited-choice' (Gabel, 2005) have the ability to display power, make choices, and find their voice despite non-interaction in the marketplace.

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Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17 beta-estradiol 3-benzoate and 17 beta-nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C-18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CC alpha) for steroids were below 0.1 mu g L-1, except for 19-norandrosterone (CC alpha = 0.7 mu g L-1) and estrone (CC alpha = 0.3 mu g L-1). Kinetics of elimination of the administered 17 beta-estradiol 3-benzoate and 17 beta-nandrolone laureate were established by monitoring 17 beta-estradiol, 17 alpha-estradiol, estrone and 17 beta-nandrolone, 17 alpha-nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17 alpha-estradiol and 17 alpha-nandrolone (> 20 and 2 mg L-1, respectively after 17 beta-estradiol 3-benzoate and 17 beta-nandrolone laureate administration) whereas 17 beta-estradiol, estrone, 17 beta-nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the mu g L-1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17 beta form. (c) 2008 Elsevier Ltd. All rights reserved.