26,393 research outputs found

    Review of the environmental and organisational implications of cloud computing: final report.

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    Cloud computing – where elastic computing resources are delivered over the Internet by external service providers – is generating significant interest within HE and FE. In the cloud computing business model, organisations or individuals contract with a cloud computing service provider on a pay-per-use basis to access data centres, application software or web services from any location. This provides an elasticity of provision which the customer can scale up or down to meet demand. This form of utility computing potentially opens up a new paradigm in the provision of IT to support administrative and educational functions within HE and FE. Further, the economies of scale and increasingly energy efficient data centre technologies which underpin cloud services means that cloud solutions may also have a positive impact on carbon footprints. In response to the growing interest in cloud computing within UK HE and FE, JISC commissioned the University of Strathclyde to undertake a Review of the Environmental and Organisational Implications of Cloud Computing in Higher and Further Education [19]

    An economical vent cover

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    Inexpensive formed-plastic vent cover has been developed that allows controlled purge of vent systems and also provides blowout protection. Cover can also be used in relief mode to allow normal system relief flows without disengaging from vent system. Cover consists of two parts made of plastics with varying densities to fit media used and desired pressures

    A review of Leptospermum scoparium (Myrtaceae) in New Zealand

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    Information about Leptospermum scoparium (Myrtaceae), the most widespread and important New Zealand indigenous shrub species, is reviewed. L. scoparium is a variable species, requiring more study of the genetically based differences between New Zealand populations and the affinity of these populations to Australian populations and other closely allied Australian species. Improved understanding of the species’ variation will assist both its conservation roles and economic uses, and the need to sustain genetically distinct varieties is emphasised. Ecologically, the species has a dominant role in infertile and poorly drained environments, and a wider occurrence as a seral shrub species in successions to forest where it may be regarded as a woody weed of pasture or a useful species for erosion control, carbon sesquestration, and vegetation restoration. The main economic products derived from the species are ornamental shrubs, essential oils, and honey. The species’ development as an ornamental plant and further definition of the pharmacologically active components are recommended as priority areas for research

    Opinion Evidence

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    Opinion Evidence

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    Effects of Chronic Cd Exposure via the Diet or Water on Internal Organ-Specific Distribution and Subsequent Gill Cd Uptake Kinetics in Juvenile Rainbow Trout (\u3cem\u3eOncorhynchus mykiss\u3c/em\u3e)

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    New regulatory approaches to metal toxicity (e.g., biotic ligand model [BLM]) focus on gill metal binding and tissue specific accumulation of waterborne metals; the dietary route of exposure and dietary/waterborne interactions are not considered, nor are the consequences of chronic exposure by either route. Therefore, we studied the effect of the same gill Cd load (∼μ2.5 mg/g), achieved by a chronic, 30-d exposure to Cd either via the diet (1,500 mg/kg) or the water (2 μg/L), on tissue-specific Cd distribution and subsequent uptake of waterborne Cd in juvenile rainbow trout (Oncorhynchus mykiss). These two exposure regimes resulted in a branchial Cd load that had been taken up across either apical gill membranes (waterborne Cd) or basolateral gill membranes (through the bloodstream for dietary Cd). The BLM characteristics of the gills (i.e., short-term Cd uptake kinetics) were altered: affinity (log KCd-Gill [95% confidence level]) decreased from 7.05 (6.75–8.76) for control to 6.54 (6.32–7.03) for waterborne Cd and 5.92 (5.83–6.51) for dietary Cd, whereas binding capacity (Bmax) increased from 3.12 (2.14–4.09) to 4.80 (3.16–6.43) and 5.50 (2.86–8.17) nmol·g-1 for control, waterborne, and dietary Cd, respectively. Fish exposed to dietary Cd accumulated a much greater overall chronic Cd body burden relative to fish exposed to waterborne Cd or control fish. The carcass accumulated the greatest percentage of total body Cd in control and waterborne-exposed fish, whereas the intestinal tissue accumulated the greatest percentage in dietary-exposed fish. Tissue-specific Cd burdens were highest in the kidney in both dietary and waterborne treatments. We conclude that chronic Cd exposure alters Cd uptake dynamics, and that the route of Cd exposure, whether waterborne or dietary, results in differences of internal Cd accumulation and branchial Cd uptake characteristics. These factors should be considered in future BLM development

    Protective Effects of Calcium Against Chronic Waterborne Cadmium Exposure to Juvenile Rainbow Trout

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    Juvenile rainbow trout (Oncorhynchus mykiss [Walbaum]) on 1% daily ration were exposed to 0 (control) or 2 μg of cadmium as Cd(NO3)2·4H2O per liter added to four different calcium (Ca) concentrations: 260 (background), 470 (low), 770 (medium), or 1200 (high) μM of Ca added as Cd(NO3)2·4H2O in synthetic soft water for 30 d. Mortality was highest (;80%) in the background 1 Cd treatment. Approximately 40% mortality was observed in the low 1 Cd exposure; mortality was 10% or less for all other treatments. No growth effects were seen for any of the exposures. Kidneys accumulated the greatest concentration of Cd during the 30 d, followed by gills and livers. Accumulation of Cd in gills, kidney, and liver decreased at higher water Ca concentrations. No differences in whole-body or plasma Ca concentrations were found. Swimming performance was impaired in the low + Cd-exposed fish. Influx of Ca2+ into whole bodies decreased as water Ca concentrations increased; influx of Ca2+ into background + Cd–treated fish was significantly reduced compared to that in control fish. Experiments that measured uptake of new Cd into gills showed that the affinity of gills for Cd (KCd-gill) and the number of binding sites for Cd decreased as water Ca concentrations increased. Acute accumulation of new Cd into gills and number of gill Cd-binding sites increased with chronic Cd exposure, whereas the affinity of gills for Cd decreased with chronic Cd exposure. Longer-term gill binding (72 h) showed reduced uptake of new Cd at higher water Ca levels and increased uptake with chronic Cd exposure. Complications were found in applying the biotic ligand model to fish that were chronically exposed to Cd because of discrepancies in the maximum number of gill Cd-binding sites among different studies

    Physiological Effects of Chronic Copper Exposure to Rainbow Trout (\u3cem\u3eOncorhynchus Mykiss\u3c/em\u3e) in Hard and Soft Water: Evaluation of Chronic Indicators

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    Effects of chronic copper exposure on a suite of indicators were examined: acute toxicity, acclimation, growth, sprint performance, whole-body electrolytes, tissue residues, and gill copper binding characteristics. Juvenile rainbow trout were exposed for 30 d to waterborne copper in hard water (hardness = 120 μg/L as CaCO3, pH = 8.0, Cu = 20 and 60 μg/L) and soft water (hardness = 20 μg/L as CaCO3, pH = 7.2, Cu = 1 and 2 μg/L). Significant acclimation to the metal occurred only in fish exposed to 60 mg/L, as seen by an approx. twofold increase in 96-h LC50 (153 vs 91 μg Cu/L). Chronic copper exposure had little or no effect on survival, growth, or swimming performance in either water hardness, nor was there any initial whole-body electrolyte loss (Na+ and Cl-). The present data suggest that the availability of food (3% wet body weight/day, distributed as three 1% meals) prevented growth inhibition and initial ion losses that usually result from Cu exposure. Elevated metal burdens in the gills and livers of exposed fish were measures of chronic copper exposure but not of effect. Initial gill binding experiments revealed the necessity of using radiolabeled Cu (64Cu) to detect newly accumulated Cu against gill background levels. Using this method, we verified the presence of saturable Cu-binding sites in the gills of juvenile rainbow trout and were able to make estimates of copperbinding affinity (log Kgill=Cu) and capacity (Bmax). Furthermore, we showed that both chronic exposure to Cu and to low water calcium had important effects on the Cu-binding characteristics of the gills

    Costs of Chronic Waterborne Zinc Exposure and the Consequences of Zinc Acclimation on the Gill/Zinc Interactions of Rainbow Trout in Hard and Soft Water

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    Juvenile rainbow trout were exposed to zinc in both moderately hard water (hardness 5 120 mg CaCO3/L, pH = 8.0, Zn = 150 μg/L or 450 μg/L) and soft water (hardness = 20 mg CaCO3/L, pH = 7.2, Zn = 50 μg/L or 120 μg/L) for 30 d. Only the 450 mg/L zinc–exposed fish experienced significant mortality (24% in the first 2 d). Zinc exposure caused no effect on growth rate, but growth affected tissue zinc levels. Whole body zinc levels were elevated, but gills and liver showed no consistent increases relative to controls over the 30-d. Therefore, tissue zinc residues were not a good indicator of chronic zinc exposure. After the 30-d exposure, physiological function tests were performed. Zinc was 5.4 times more toxic in soft water (control 96 h LC50s in hard and soft water were 869 μg/L and 162 μg/L, respectively). All zinc-exposed trout had acclimated to the metal, as seen by an increase in the LC50 of 2.2 to 3.9 times over that seen in control fish. Physiological costs related to acclimation appeared to be few. Zinc exposure had no effect on whole body Ca2+ or Na+ levels, on resting or routine metabolic rates, or on fixed velocity sprint performance. However, critical swimming speed (UCrit) was significantly reduced in zinc-exposed fish, an effect that persisted in zinc-free water. Using radioisotopic techniques to distinguish new zinc incorporation, the gills were found to possess two zinc pools: a fast turnover pool (T1/2 = 3–4 h) and a slow turnover pool (T1/2 = days to months). The fast pool was much larger in soft water than in hard water, but at most it accounted for \u3c3.5% of the zinc content of the gills. The size of the slow pool was unknown, but its loading rate was faster in soft water. Chronic zinc exposure was found to increase the size of the fast pool and to increase the loading rate of the slow pool
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