202 resultados para Ventilated stone veneer
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Child neglect continues to be the most prevalent form of child maltreatment, yet it has received less specific research attention than other forms of maltreatment (Zuravin, 1999). It is only in recent years that neglect has been seen as a phenomenon that needs to be conceptualised separately to other forms of abuse (Gershater- Molko et al., 2002). Although the term ‘neglect’ is used generally when children do not receive minimal physical and/or emotional care, there is no single agreed definition; one possible reason for this is the lack of consensus about minimally adequate standards of childcare either within professional groups or existing research (Rose and Meezan, 1996; Stone, 1998).
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Objective: Prolonged limb ischemia followed by reperfusion (I/R) is associated with a systemic inflammatory response syndrome and remote acute lung injury. Ischemic preconditioning (IPC), achieved with repeated brief periods of I/R before the prolonged ischemic period, has been shown to protect skeletal muscle against ischemic injury. The aim of this study was to ascertain whether IPC of the limb before I/R injury also attenuates systemic inflammation and acute lung injury in a fully resuscitated porcine model of hind limb I/R. Methods: This prospective, randomized, controlled, experimental animal study was performed in a university-based animal research facility with 18 male Landrace pigs that weighed from 30 to 35 kg. Anesthetized ventilated swine were randomized (n = 6 per group) to three groups: sham-operated control group, I/R group (2 hours of bilateral hind limb ischemia and 2.5 hours of reperfusion), and IPC group (three cycles of 5 minutes of ischemia/5 minutes of reperfusion immediately preceding I/R). Plasma was separated and stored at -70° C for later determination of plasma tumor necrosis factor-a and interleukin-6 with bioassay as markers of systemic inflammation. Circulating phagocytic cell priming was assessed with a whole blood chemiluminescence assay. Lung tissue wet-to-dry weight ratio and myeloperoxidase concentration were markers of edema and neutrophil sequestration, respectively. The alveolar-arterial oxygen gradient and pulmonary artery pressure were indices of lung function. Results: In a porcine model, bilateral hind limb (I/R) injury significantly increased plasma interleukin-6 concentrations, circulating phagocytic cell priming, and pulmonary leukosequestration, edema, and impaired gas exchange. Conversely, pigs treated with IPC before the onset of the ischemic period had significantly reduced interleukin-6 levels, circulating phagocytic cell priming, and experienced significantly less pulmonary edema, leukosequestration, and respiratory failure. Conclusion: Lower limb IPC protects against systemic inflammation and acute lung injury in lower limb I/R injury.
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OBJECTIVE: To investigate the role of recombinant bactericidal/permeability-increasing protein (rBPI21) in the attenuation of the sepsis syndrome and acute lung injury associated with lower limb ischemia-reperfusion (I/R) injury. SUMMARY BACKGROUND DATA: Gut-derived endotoxin has been implicated in the conversion of the sterile inflammatory response to a lethal sepsis syndrome after lower torso I/R injury. rBPI21 is a novel antiendotoxin therapy with proven benefit in sepsis. METHODS: Anesthetized ventilated swine underwent midline laparotomy and bilateral external iliac artery occlusion for 2 hours followed by 2.5 hours of reperfusion. Two groups (n = 6 per group) were randomized to receive, by intravenous infusion over 30 minutes, at the start of reperfusion, either thaumatin, a control-protein preparation, at 2 mg/kg body weight, or rBPI21 at 2 mg/kg body weight. A control group (n = 6) underwent laparotomy without further treatment and was administered thaumatin at 2 mg/kg body weight after 2 hours of anesthesia. Blood from a carotid artery cannula was taken every half-hour for arterial blood gas analysis. Plasma was separated and stored at -70 degrees C for later determination of plasma tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 by bioassay, and IL-8 by enzyme-linked immunosorbent assay (ELISA), as a markers of systemic inflammation. Plasma endotoxin concentration was measured using ELISA. Lung tissue wet-to-dry weight ratio and myeloperoxidase concentration were used as markers of edema and neutrophil sequestration, respectively. Bronchoalveolar lavage protein concentration was measured by the bicinclinoic acid method as a measure of capillary-alveolar protein leak. The alveolar-arterial gradient was measured; a large gradient indicated impaired oxygen transport and hence lung injury. RESULTS: Bilateral hind limb I/R injury increased significantly intestinal mucosal acidosis, intestinal permeability, portal endotoxemia, plasma IL-6 concentrations, circulating phagocytic cell priming and pulmonary leukosequestration, edema, capillary-alveolar protein leak, and impaired gas exchange. Conversely, pigs treated with rBPI21 2 mg/kg at the onset of reperfusion had significantly reduced intestinal mucosal acidosis, portal endotoxin concentrations, and circulating phagocytic cell priming and had significantly less pulmonary edema, leukosequestration, and respiratory failure. CONCLUSIONS: Endotoxin transmigration across a hyperpermeable gut barrier, phagocytic cell priming, and cytokinemia are key events of I/R injury, sepsis, and pulmonary dysfunction. This study shows that rBPI21 ameliorates these adverse effects and may provide a novel therapeutic approach for prevention of I/R-associated sepsis syndrome.
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Genetic variation of the alpha-synuclein gene (SNCA) is known to cause familial parkinsonism, however the role of SNCA variants in sporadic Parkinson's disease (PD) remains elusive. The present study identifies an association of common SNCA polymorphisms with disease susceptibility in a series of Irish PD patients. There is evidence for association with alternate regions, of protection and risk which may act independently/synergistically, within the promoter region (Rep1; OR: 0.59, 95% CI: 0.37-0.84) and the 3'UTR of the gene (rs356165; OR: 1.67, 95% CI: 1.08-2.58). Given previous reports of association a collaborative effort is required which may exploit global linkage disequilibrium patterns for SNCA and standardise polymorphic markers used in each population. It is now crucial to identify the susceptibility allele and elucidate its functionality which may generate a therapeutic target for PD.
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A comparative study of models used to predict contaminant dispersion in a partially stratified room is presented. The experiments were carried out in a ventilated test room, with an initially evenly dispersed pollutant. Air was extracted from the outlet in the ceiling of the room at 1 and 3 air changes per hour. A small temperature difference between the top and bottom of the room causes very low air velocities, and higher concentrations, in the lower half of the room. Grid-independent CFD calculations were compared with predictions from a zonal model and from CFD using a very coarse grid. All the calculations show broadly similar contaminant concentration decay rates for the three locations monitored in the experiments, with the zonal model performing surprisingly well. For the lower air change rate, the models predict a less well mixed contaminant distribution than the experimental measurements suggest. With run times of less than a few minutes, the zonal model is around two orders of magnitude faster than coarse-grid CFD and could therefore be used more easily in parametric studies and sensitivity analyses. For a more detailed picture of internal dispersion, a CFD study using coarse and standard grids may be more appropriate.
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Sporting with the Classics: The Latin Poetry of William Dillingham (2010) (back cover)
Dana Sutton, University of California:
‘The great merit of Estelle Haan's study is that she is willing to take Dillingham seriously as a poet. Her reproduction of his work, together with an English translation and very detailed studies of his individual poems have the combined effect of rescuing an interesting poet from near-total oblivion. This, in my opinion, is the finest thing a neo-Latin scholar can do, and Haan accomplishes her task with the same skill, sensitivity, and eloquence that have distinguished her studies of other neo-Latin poets of this period (Joseph Addison and Vincent Bourne). It is impossible not to react to this volume with extreme respect and appreciation’.
Gordon Campbell, University of Leicester:
‘Nothing substantial has ever been published on Dillingham, but with this volume we have a new corpus of poetry that intersects with the work of many other seventeenth-century neo-Latin and vernacular poets. Professor Haan’s scholarship is here (as always) placed at the service of the poet, and she leads the reader gently through the work of a new poet. Professor Haan is the most eminent and able neo-Latinist of her generation, and her scholarship never fails; sometimes it dazzles as in the chapters on the hangman's stone and on Renaissance topiary. Her research is always up-to-date, and her translations have a gracefulness that other laborers in the vineyard can only envy’.
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Fire has long been recognized as an agent of rock weathering. Our understanding of the impact of fire on stone comes either from early anecdotal evidence, or from more recent laboratory simulation studies, using furnaces to simulate the effects of fire. This paper suggests that knowledge derived from simulated heating experiments is based on the preconceptions of the experiment designer – when using a furnace to simulate fire, the operator decides on the maximum temperature and the duration of the experiment. These are key factors in determining the response of the stone to fire, and if these are removed from realworld observations then knowledge based on these simulations must be questioned. To explore the differences between heating sandstone in a furnace and a real fire, sample blocks of Peakmoor Sandstone were subjected to different stress histories in combination (lime rendering and removal, furnace heating or fire, frost and salt weathering). Block response to furnace heating and fire is discussed, with emphasis placed on the non-uniformity of the fire and of block response to fire in contrast to the uniform response to surface heating in a furnace. Subsequent response to salt weathering (by a 10% solution of sodium chloride and magnesium sulphate) was then monitored by weight loss. Blocks that had experienced fire showed a more unpredictable response to salt weathering than those that had undergone furnace heating – spalling of corners and rapid catastrophic weight loss were evidenced in blocks that had been subjected to fire, after periods of relative quiescence. An important physical side-effect of the fire was soot accumulation, which created a waxy, relatively impermeable layer on some blocks. This layer repelled water and hindered salt ingress, but eventually detached when salt, able to enter the substrate through more permeable areas, concentrated and crystallized behind it, resulting in rapid weight loss and accelerated decay. Copyright ©2007 John Wiley & Sons, Ltd.
Interpreting spatial complexity of decay features on a sandstone wall: St. Matthew’s Church, Belfast
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This paper describes the development of neural model-based control strategies for the optimisation of an industrial aluminium substrate disk grinding process. The grindstone removal rate varies considerably over a stone life and is a highly nonlinear function of process variables. Using historical grindstone performance data, a NARX-based neural network model is developed. This model is then used to implement a direct inverse controller and an internal model controller based on the process settings and previous removal rates. Preliminary plant investigations show that thickness defects can be reduced by 50% or more, compared to other schemes employed. (c) 2004 Elsevier Ltd. All rights reserved.
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Sargassum muticum is an invasive brown macroalga that originates from Japan. In the introduced range, thalli can grow in soft substratum habitats attached to embedded rock fragments and shells, Within Strangford Lough, Northern Ireland, S. muticum has rapidly colonised large areas of soft substrata, where dispersal by peripatetic or 'stone-walking' plants is very effective. Sediment cores were collected under and outside canopies of S. muticum in Strangford Lough (S. muticum first recorded there in 1995) and Langstone Harbour, English Channel (S. muticum first found there in 1974) to investigate modification of the infaunal assemblages. At both study sites, community analyses highlighted significant differences between the assemblages under the canopies and those in adjacent unvegetated areas. In Strangford Lough, the invertebrate community under the canopy contained a higher abundance of smaller, opportunistic, r-selected species than outside the canopy. By contrast, the communities under and outside the canopy at Langstone Harbour were similar in species composition, diversity and dominance, but overall faunal abundance was greater under the canopy. Sediment characteristics were not affected by S. muticum canopies, but the infaunal changes may be related to environmental modification; shading, flow suppression and temperature stratification were also investigated. The differences between these 2 sites indicate that localised conditions and/or the duration of colonisation of S. muticum are important in determining the nature of habitat modification.
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This paper reports an experimental investigation of converting waste medium density fibreboard (MDF) sawdust into chars and activated carbon using chemical activation and thermal carbonisation processes. The MDF sawdust generated during the production of architectural mouldings was characterised and found to have unique properties in terms of fine particle size and high particle density. It also has a high content of urea formaldehyde resin used as a binder in the manufacturing of MDF board. Direct thermal carbonisation and chemical activation of the sawdust by metal impregnation and acid (phosphoric acid) treatment prior to pyrolysis treatment were carried out. The surface morphology of the raw dust, its chars and activated carbon were examined using scanning electron microscopy (SEM). Adsorptive properties and total pore volume of the materials were also analysed using the BET nitrogen adsorption method. Liquid adsorption of a reactive dye (Levafix Brilliant red E-4BA) by the derived sawdust carbon was investigated in batch isothermal adsorption process and the results compared to adsorption on to a commercial activated carbon (Filtrasorb F400). The MDF sawdust carbon exhibited in general a very low adsorption capacity towards the reactive dye, and physical characterisation of the carbon revealed that the conventional chemical activation and thermal carbonisation process were ineffective in developing a microporous structure in the dust particles. The small size of the powdery dust, the high particle density, and the presence of the urea formaldehyde resin all contributed to the difficulty of developing a proper porous structure during the thermal and chemical activation process. Finally, activation of the dust material in a consolidated form (cylindrical pellet) only achieved very limited improvement in the dye adsorption capacity. This original study, reporting some unexpected outcomes, may serve as a stepping-stone for future investigations of recycle and reuse of the waste MDF sawdust which is becoming an increasing environmental and cost liability. (C) 2004 Elsevier Ltd. All rights reserved.