509 research outputs found
A case study of arrival and departure managers cooperation for reducing airborne holding times at destination airports
Congestion of flights arriving at terminal areas invariably leads to aircraft having to extend their flying time, which often results in the need to orbit at a holding point as aircraft are sequenced to land. This extended flying time can be significantly reduced by the implementation of the delay-on-ground concept, where aircraft flying short sectors are delayed in their departure from the respective airport, thus reducing the amount of congestion at the destination point. This paper analysis the impact, in terms of reduced flying time, fuel burn and carbon emissions, that can be achieved at Oslo-Gardemoen airport if the present flights that have a flying time of 1 hour or less are delayed on the ground at their departure point. The impact such a concept would have if traffic densities of 15% and 30% above current levels were to be experienced is also considered
Micro and macro quadcopter drones for indoor mapping to support disaster management
In this paper we present the operations and mapping techniques of two drones that are different in terms of size, the sensors deployed, and the positioning and mapping techniques used. The first drone is a low-cost commercial quadcopter microdrone, a Crazyflie, while the second drone is a relatively expensive research quadcopter macrodrone, called MAX. We investigated their feasibility in mapping areas where satellite positioning is not available, such as indoor spaces
Effects of portion size on chronic energy intake
© 2007 Jeffery et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
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Guidelines for consideration of bats in lighting projects.
Eighty percent of the world’s population are currently exposed to light-polluted skies, and the Milky Way is no longer visible to more than a third of humanity. The pace the light pollution is increasing is faster than global population growth and economic development. While environmental conditions at night are being dramatically and rapidly altered, circadian rhythms, behaviour and ecology of plants and animals are imminently influenced. In the same time, effects of artificial lighting, various illumination schemes and spectra on biodiversity, including bats, are currently insufficiently understood, whereas only a vague notion of required mitigation and compensation activities exists among decision-makers and other parties involved in lighting projects. Although the bats are almost exclusively nocturnal and extremely sensitive to multiple effects of light pollution, its negative impact on bats alongside essential measures needed to preserve unfragmented nightscapes for these animals are often disregarded during impact assessments, planning and operation.
In this volume, we tried to compile available evidence related to the effect of artificial light at night on the European bats. Based on the current state of knowledge, solutions are proposed concerning possible ways to avoid, mitigate and compensate the adverse effects which lighting projects may have on bats and their functional habitats. We also outlined research priorities for future studies, required for in-depth understanding of the problem and assessing efficiency of proposed mitigative measures
Theories of Willpower Affect Sustained Learning
Building cognitive abilities often requires sustained engagement with effortful tasks. We demonstrate that beliefs about willpower–whether willpower is viewed as a limited or non-limited resource–impact sustained learning on a strenuous mental task. As predicted, beliefs about willpower did not affect accuracy or improvement during the initial phases of learning; however, participants who were led to view willpower as non-limited showed greater sustained learning over the full duration of the task. These findings highlight the interactive nature of motivational and cognitive processes: motivational factors can substantially affect people’s ability to recruit their cognitive resources to sustain learning over time
Neutrophil cannibalism – a back up when the macrophage clearance system is insufficient
BACKGROUND: During a lipopolysaccharide-induced lung inflammation, a massive accumulation of neutrophils occurs, which is normally cleared by macrophage phagocytosis following neutrophil apoptosis. However, in cases of extensive apoptosis the normal clearance system may fail, resulting in extensive neutrophil secondary necrosis. The aim of this study was to explore the hypothesis that neutrophils, in areas of the lung with extensive cellular infiltration, contribute to clearance by phagocytosing apoptotic cells and/or cell debris derived from secondary necrosis. METHODS: Intranasal lipopolysaccharide administration was used to induce lung inflammation in mice. The animals were sacrificed at seven time points following administration, bronchoalveolar lavage was performed and tissue samples obtained. Electron microscopy and histochemistry was used to assess neutrophil phagocytosis. RESULTS: Electron microscopic studies revealed that phagocytosing neutrophils was common, at 24 h after LPS administration almost 50% of the total number of neutrophils contained phagosomes, and the engulfed material was mainly derived from other neutrophils. Histochemistry on bronchoalvolar lavage cells further showed phagocytosing neutrophils to be frequently occurring. CONCLUSION: Neutrophils are previously known to phagocytose invading pathogens and harmful particles. However, this study demonstrates that neutrophils are also able to engulf apoptotic neutrophils or cell debris resulting from secondary necrosis of neutrophils. Neutrophils may thereby contribute to clearance and resolution of inflammation, thus acting as a back up system in situations when the macrophage clearance system is insufficient and/or overwhelmed
Treatment of the displaced femoral neck fracture, as reflected in Acta Orthopaedica Scandinavica: The rise and fall of internal fixation
Liax Is a Surrogate Marker For Cell Envelope Stress and Daptomycin Non-Susceptibility in Enterococcus Faecium
Daptomycin (DAP) is often used as a first-line therapy to treat vancomycin-resistan
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