2,159 research outputs found

    A curriculum for excellence review of research literature

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    Research suggests that the arts play significant part in the education of all pupils. The findings of numerous, wide-ranging studies indicate that the Expressive Arts fulfil a vital function in the development learners, meeting many of the outcomes described in the "Purposes of the Curriculum 3-18" diagram outlined on page 15 of "A Curriculum for Excellence". In the following review of recent research, it is evident that the arts provide meaningful contexts through which learners can actively participate in a wide range of learning experiences. It is evident that learning should take place in the arts: each separate discipline has its own knowledge and skills base. But learning also takes place through the arts. Because of the high level of active engagement and enjoyment experienced during good Expressive Arts lessons, learners gain a sense of achievement and increased self-esteem. Across the arts areas, learners are offered a very wide and varied range of experiences, enabling them to communicate in a number of ways, for example, orally, visually, through body language and through music. The collaborative nature of many arts activities enables learners to develop skills in working cooperatively with others, often in problem-solving, creative situations. The arts also offer many opportunities for learners to be pro-active and enterprising within meaningful and relevant contexts

    Effects of Apamin and Charybdtoxin on Endothelium Independent Vasodilatation : Implications in the study of EDHF

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    Endothelial derived hyperpolarizing factor (EDHF), together with endothelial derived NO and prostacyclin represent the major endogenous vasodilator hormone pathways (Coleman et al, 2004). Since the chemical nature of EDHF is uncertain, many studies have relied on pharmacological tools. Often EDHF described as the endothelial dependent dilation which is resistant to a combination of drugs that inhibit NO synthase (usually L-NAME) and cyclo-oxygenase (usually indomethacin) but abolished by those that block large and small Ca2+-activated K+ channels (BKCa and SKCa; with charybdotoxin plus apamin respectively). This approach relies on each of these drugs being selective for endothelial dependent responses. In the current study we have taken a different approach to most and performed experiments where inhibitors were added to endothelium denuded vessels after dilators induced stable vasodilatation. Male Wistar rats (200 ± 15.4g) were killed by lethal exposure to CO2. Second order mesenteric arteries were mounted in isometric wire myographs and vasomotor responses recorded as described previously (Harrington and Mitchell, 2004). In some experiments vessels were contracted with EC80 concentration of U46619, dilation was then induced by the addition of 3x10-6M acetylcholine or 3x10-6M SNP. When either L-NAME (10-4M) or charybdotoxin (10-7M) plus apamin (5x10-7M) were added after acetylcholine the vasodilatation was immediately and completely reversed (Figure A and B respectively). In other experiments, endothelium independent vasodilation induced by SNP, were also reversed by charybdotoxin plus apamin, but not L-NAME. Figure A. Example trace of an artery re-contracting following the addition of L-NAME in pre-contracted arteries dilated with acetylcholine. Bar Graphs show re-contraction of arteries in response to L-NAME or charybdotoxin plus apamin (C+A) in arteries with endothelium, dilated with acetylcholine (Figure B) or without endothelium dilated with SNP (Figure C). This data demonstrates that charybdotoxin and apamin have pharmacological effects independent of the endothelium, at the level of smooth muscle cell function. These observations suggest results obtained with these drugs in relation to EDHF studies, should be treated with caution. Harrington L and Mitchell JA (2004) Br J Pharmacol 143: 611-617 Coleman et al (2004) Clin Ex Pharm Phys 31; 641-649Peer reviewedFinal Accepted Versio

    Role of brain monoamine systems in intra-cranial self-stimulation

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    Nitrogen and phosphorus budgets for the central Great Barrier Reef Shelf

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    Shelf-scale budgets were developed for the nutrient elements nitrogen (N) and phosphorus (P) in the central Great Barrier Reef between Cape Tribulation (I 60 S} and Dunk Island (ca. 18°S). The intent was to quantify: I} stocks of nutrients (nitrogen (N). phosphorus (P) and silicon (Si}) naturally occurring in central Great Barrier Reef waters; 2) natural gradients and variability in water column nutrient concentrations; 3} natural fluxes of nutrients into and out of shelf waters for comparison with anthropogenic or anthropogenically affected nutrient sources

    A modern approach to the Heckel Equation: The effect of compaction pressure on the yield pressure of ibuprofen and its sodium salt

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    Despite being heavily criticised in the literature the most widely used and accepted compaction equation is the Heckel equation proposed by Heckel in 1961. Its presence in literature for 55 years is due to the ease in which it can distinguish between plastic and brittle materials. Achieving the correct balance of plastic and brittle materials in a formulation is critical to ensure adequate tablet strength is achieved therefore classifying materials using the Heckel equation is attractive. Despite the importance of this understanding, especially in the design and manufacture of direct compression formulations, there are no set analytical testing standards or materials classification guidelines. Instead many workers have attempted to develop techniques for the measurement and classification of a materials deformation but there is still confusion and contradiction present in this field. In this study we repot on report the effect of compaction pressure on the yield pressure of ibuprofen and its sodium salt. Ibuprofen and its sodium salt were selected as models for study due to the availability of comparative literature yield pressure values. The reported variation in yield pressure can be significant e.g, ibuprofen which has literature values of 21-1139 MPa. This study proposes an approach to determine yield pressure from the Heckel equation using a linear regression method. The full linear regression methodology utilised is described and is used to report the yield pressure of ibuprofen and its sodium salt dihydrate. This technique reveals the most representative compaction pressure in order to derive yield pressure to be 121 MPa. The yield pressure of ibuprofen and its sodium salt have been shown to increase with increasing compaction pressure. The reported values lie between 52-78 MPa for ibuprofen and 48-75 MPa for ibuprofen sodium dihydrate. The slightly lower reported yield pressure values for ibuprofen sodium suggest increased plasticity which could be attributed to the water contained within the structure acting as a plasticiser

    Dredged sediment for agriculture: Lake Paradise

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    Lake Paradise, a water supply lake for Mattoon, Illinois, has lost much of its capacity due to sediment. This was a study to determine the agricultural benefit of Lake Paradise sediment when applied to farmland on the lake watershed. About 170 cubic yards of sediment were hauled to a demonstration site. While this method is probably not practical economically on an agricultural scale, it did provide a way to evaluate the sediment productivity during the short (one year) term of this project. About 2100 yards of sediment were also pumped to the demonstration site using a hydraulic dredge. This was stored behind agricultural terraces and is being dewatered using three subsurface drainage methods. A study was also conducted of the water chemistry of Lake Paradise during the dredging operation. Results showed a significant yield increase of corn yields on the hauled sediment plots compared to the original farmland. About $100 per acre increased net returns resulted which would help defray some costs of lake reclamation. It was found that the costs of lake reclamation by applying dredged sediment to farmland using terraces is directly related to the steepness of the land slope. Spray irrigating sediment was found to be comparable in cost to storing behind terraces with the disadvantage that spray irrigation is limited to soils or special soil management practices where erosion can be controlled. A study was conducted of the water chemistry of Lake Paradise during the dredging operation. Results showed that the project had a minimal effect on lake water quality.U.S. Geological SurveyU.S. Department of the InteriorOpe

    Hot String Soup

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    Above the Hagedorn energy density closed fundamental strings form a long string phase. The dynamics of weakly interacting long strings is described by a simple Boltzmann equation which can be solved explicitly for equilibrium distributions. The average total number of long strings grows logarithmically with total energy in the microcanonical ensemble. This is consistent with calculations of the free single string density of states provided the thermodynamic limit is carefully defined. If the theory contains open strings the long string phase is suppressed.Comment: 13 pages, no figures, uses LaTex, some errors in equations have been corrected, NSF-ITP-94-83, UCSBTH-94-3

    Dissolution geology of organic materials on Saturn’s moon Titan: alien analogs of terrestrial karst

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    Karst or dissolution geology can occur whenever a circulating fluid can dissolve a geological material. On Earth, the “classical” karst definition is for limestone (CaCO3) in water (H2O), but other material/solvent combinations can create terrestrial dissolution terrain as well. These include so-called “evaporite karst materials” such as halite (NaCl)/H2O or gypsum (CaSO4)/H2O, dolomite (CaMg(CO3)2)/H2O, and even silica (SiO2)/H2O [Ford and Williams, 2007].  On Mars, there has been the suggestion of kieserite (MgSO4)/H2O system that may have formed in an earlier, wetter environment [Baroni and Sgavetta, 2013]. Saturn’s moon Titan extends the definition of karst to include non-aqueous liquids dissolving a landscape made of organic materials. The Cassini mission has provided evidence that Titan’s 1.5 bar nitrogen atmosphrere and cryogenic 94 K surface temperature supports a hydrocarbon-based cycle on Titan similar to the terrestrial water cycle. These circulating liquids may be capable of dissolving some of the surface organic molecules derived from Titan’s complex atmospheric photochemistry. Although under a different gravity, temperature, materials and fluid regime, many of the features on Titan’s surface bear striking resemblances to terrestrial karst terrains. Our investigations have focused on the labyrinth terrains of Titan. These are elevated plateaux of organic materials that appear similar to polygonal karst, tower karst, and fluviokarst on Earth [Malaska et al., 2010; 2017]. Remote sensing data is consistent with these plateaux being constructed of low-dielectric organic materials [Janssen et al. 2009; 2016; Malaska et al, 2016b]. Theoretical calculations followed by cryogenic laboratory experiments have shown that organic materials found on Titan’s surface will dissolve when subjected to Titan’s rainfall of methane-rich fluids [Raulin, 1987; Lorenz and Lunine, 1996; Malaska et al., 2010; 2011; Malaska and Hodyss, 2014; Cornet et al., 2015] and preliminary modelling has been able to reproduce some of the morphologies observed on Titan [Cornet et al., 2017]. Titan’s labyrinth terrains may originate as mixed organic windblown sediments that are later lithified in a process similar to calcite-cemented sandstone on Earth. Organic molecules and sediments produced by Titan’s rich organic photochemistry include organic molecules such as acetylene (C2H2), ethylene (C2H4), hydrogen cyanide (HCN),  benzene (C2H6), acrylonitrile (C2H3CN), acetonitrile (CH3CN), cyanoacetylene (HC2CN), other alkynes and nitriles, and a complex refractory organic materials similar to laboratory tholins. Once uplifted, the saturation equilibrium and kinetics of dissolution for each material and fluid combination affecting the plateau may play key roles in determining how the karstic system will evolve [Malaska et al., 2011; Cornet et al., 2015]. Some of the Titan organic minerals will dissolve, while some will be left behind as an insoluble lag deposit. Advanced laboratory investigations of organic materials on Titan is underway to further understand how these geological structures evolve and compare them with the formation processes of terrestrial analogs. We suggest that karst is a general planetary process wherever circulating fluids are capable of dissolving materials and developing subsurface drainage
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