4,435 research outputs found

    Using blubber explants to investigate adipose function in grey seals:glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone

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    Adipose tissue is fundamental to energy balance, which underpins fitness and survival. Knowledge of adipose regulation in animals that undergo rapid fat deposition and mobilisation aids understanding of their energetic responses to rapid environmental change. Tissue explants can be used to investigate adipose regulation in wildlife species with large fat reserves, when opportunities for organismal experimental work are limited. We investigated glucose removal, lactate, glycerol and NEFA accumulation in media, and metabolic gene expression in blubber explants from wild grey seals. Glycolysis was higher in explants incubated in 25 mM glucose (HG) for 24 h compared to controls (C: 5.5 mM glucose). Adipose-derived lactate likely contributes to high endogenous glucose production in seals. Lipolysis was not stimulated by HG or high hydrocortisone (HC: 500 nM hydrocortisone) and was lower in heavier animals. HC caused NEFA accumulation in media to decrease by ~30% relative to C in females, indicative of increased lipogenesis. Lipolysis was higher in males than females in C and HG conditions. Lower relative abundance of 11-β-hydroxysteroid dehydrogenase 1 mRNA in HG explants suggests glucose involvement in blubber cortisol sensitivity. Our findings can help predict energy balance responses to stress and nutritional state in seals, and highlight the use of explants to study fat tissue function in wildlife

    Energetic, environmental and economic modelling of a solar-assisted residential micro-trigeneration system in a Mediterranean climate

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    Reducing energy consumption in buildings has become a priority for most countries. However, designing energy-efficient buildings is not a straightforward task - the increasing demand for high comfort standards, provided by conventional 'energy-hungry' cooling and heating devices conflicts with the need for demand reduction. Trigeneration, the simultaneous production of electricity, cooling and heating is often viewed as a means of improving energy-efficiency in large and medium sized buildings whilst still delivering thermal comfort. For hot climates, the benefit of utilising the waste heat emitted from an engine unit to power a thermally driven cooling device provides scope to utilise an otherwise wasted energy stream. However, in smaller sized residential buildings, the relatively low and intermittent energy demand coupled with high capital costs, has stifled the uptake of the technology - although the potential for substantial energy savings exists. Moreover, it is very common for home owners in hot climates to opt for other energy-saving devices such as solar water heaters (SWH), which would tend to reduce further the possible demand for space and water heating, possibly making the simultaneous use of both micro-trigeneration and SWH unfeasible. This paper compares the performance of a residential micro-trigeneration system to a hybrid micro-trigeneration/SWH system. The performance of both systems was simulated using a whole building simulation tool run at a high time resolution. The results obtained were then used to quantify the energetic and environmental performance of both systems; and also to assess their financial viability against the effect of varying fuel prices, electricity tariffs and a varying Feed-in Tariff (FIT). Results show that whereas the solar aided micro-trigeneration system obtains an overall higher (though marginal) energetic and environmental performance, the financial performance for the same fiscal parameters (fuel prices and electricity tariffs) deteriorates. Moreover FIT, plays an important role in the financial feasibility of the system

    Consumer insights and the importance of competitiveness Factors for mature and developing destinations

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    This article aims to understand the importance of various destination attributes to the competitiveness of tourism destinations from a consumer perspective, while at the same time contrasting these in a mature versus developing destination. A sample of Australian-based domestic tourists were surveyed to assess the relative importance of tourism destination competitiveness (TDC) attributes in the context of developing and mature destinations. This research firstly appears to verify that the importance of many TDC elements, highlighted by consumers, is not dissimilar from other stakeholder-based TDC studies. Furthermore, this research effort established that in terms of attribute performance, relative destination immaturity may well constrain a developing destination’s ability to satisfy the needs of consumers

    Energetic, environmental and economic modeling of a solar-assisted residential micro-trigeneration system in a Mediterranean climate

    Get PDF
    Reducing energy consumption in buildings has become a priority for most countries. However, designing energy-efficient buildings is not a straightforward task - the increasing demand for high comfort standards, provided by conventional ‘energy-hungry’ cooling and heating devices conflicts with the need for demand reduction. Trigeneration, the simultaneous production of electricity, cooling and heating is often viewed as a means of improving energy-efficiency in large and medium sized buildings whilst still delivering thermal comfort. For hot climates, the benefit of utilising the waste heat emitted from an engine unit to power a thermally driven cooling device provides scope to utilise an otherwise wasted energy stream. However, in smaller sized residential buildings, the relatively low and intermittent energy demand coupled with high capital costs, has stifled the uptake of the technology - although the potential for substantial energy savings exists. Moreover, it is very common for home owners in hot climates to opt for other energy-saving devices such as solar water heaters (SWH), which would tend to reduce further the possible demand for space and water heating, possibly making the simultaneous use of both micro-trigeneration and SWH unfeasible. This paper compares the performance of a residential micro-trigeneration system to a hybrid micro-trigeneration/SWH system. The performance of both systems was simulated using a whole building simulation tool run at a high time resolution. The results obtained were then used to quanti fy the energetic and environmental performance of both systems; and also to assess their financial viability against the effect of varying fuel prices, electricity tariffs and a varying Feed-in Tariff (FIT). Results show that whereas the solar aided micro-trigeneration system obtains an overall higher (though marginal) energetic and environmental performance, the financial performance for the same fiscal parameters (fuel prices and electricity tariffs) deteriorates. Moreover FIT, plays an important role in the financial feasibility of the system.peer-reviewe

    Potential for natural and enhanced attenuation of sulphanilamide in a contaminated chalk aquifer

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    Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry (IRMS) method was developed to evaluate the extent of biodegradation of the antibiotic, sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ13C of 8.44‰ from − 26.56 (at the contaminant source) to − 18.12‰ (300 m downfield of the source). These results confirm reductions in sulphanilamide concentrations (from 650 to 10 mg/L) across the contaminant plume to be attributable to biodegradation (56%) vs. other natural attenuation processes, such as dilution or dispersion (42%). To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity (~ 50% mineralisation) to degrade sulphanilamide under high (263 mg/L), moderate (10 mg/L) and low (0.02 mg/L) substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions

    Direct synthesis of hydrogen peroxide in water at ambient temperature

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    The direct synthesis of hydrogen peroxide (H2O2) from hydrogen and oxygen has been studied using an Au–Pd/TiO2 catalyst. The aim of this study is to understand the balance of synthesis and sequential degradation reactions using an aqueous, stabilizer-free solvent at ambient temperature. The effects of the reaction conditions on the productivity of H2O2 formation and the undesirable hydrogenation and decomposition reactions are investigated. Reaction temperature, solvent composition and reaction time have been studied and indicate that when using water as the solvent the H2O2 decomposition reaction is the predominant degradation pathway, which provides new challenges for catalyst design, which has previously focused on minimizing the subsequent hydrogenation reaction. This is of importance for the application of this catalytic approach for water purification

    Airbag-related chest wall burn as a marker of underlying injury: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>This case of a man who sustained an airbag-induced thoracic injury and burn, highlights the potential harm that can be caused by airbags. It also serves to illustrate that a surface burn which looks small and benign can actually be a surface marker of a more serious injury. Staff working in emergency departments need to be aware of the risk of possible airbag-associated injuries.</p> <p>Case presentation</p> <p>A 65-year-old man was the driver in a frontal collision. He was wearing a seatbelt. The airbag was activated and caused a superficial chest wall burn. Initial chest x-rays were unremarkable but following deterioration in his condition, a computed tomography scan revealed a serious sternal fracture. The location of the fracture was marked on the surface by the burn.</p> <p>Conclusion</p> <p>Airbags can cause significant chest wall injuries and burns. Surface burns at the point of impact should not be dismissed as trivial as the forces involved can cause significant injury. We recommend that all people with chest wall injuries and/or burns due to airbags should have more detailed chest imaging as initial emergency radiographs can be falsely reassuring.</p

    Generative Design in Minecraft (GDMC), Settlement Generation Competition

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    This paper introduces the settlement generation competition for Minecraft, the first part of the Generative Design in Minecraft challenge. The settlement generation competition is about creating Artificial Intelligence (AI) agents that can produce functional, aesthetically appealing and believable settlements adapted to a given Minecraft map - ideally at a level that can compete with human created designs. The aim of the competition is to advance procedural content generation for games, especially in overcoming the challenges of adaptive and holistic PCG. The paper introduces the technical details of the challenge, but mostly focuses on what challenges this competition provides and why they are scientifically relevant.Comment: 10 pages, 5 figures, Part of the Foundations of Digital Games 2018 proceedings, as part of the workshop on Procedural Content Generatio
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