| 1. |
- Duppils, Sara, 1975-
(författare)
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Gastkramad
- 2015
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Ingår i: Spirit Possession around the World<em></em>. - Santa Barbara : ABC-CLIO. - 9781610695893 ; , s. 129-
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Clementson, Martin, et al.
(författare)
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Is early mobilisation better than immobilisation in the treatment of wrist sprains?
- 2016
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - 2000-656X. ; :Feb 6, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Posttraumatic radial sided wrist pain is common and can represent a fracture or a ligament injury. However, in some patients radiographs and MRI are normal, indicating no specific diagnosis other than a wrist sprain. There is no consensus on the ideal treatment for this patient group. The aim was to investigate if patients with posttraumatic radial sided wrist pain and MRI not showing signs of fracture or SL-ligament injury should be treated with immediate mobilisation or 2 weeks cast immobilisation.
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| 3. |
- Kersten, Anton, 1991, et al.
(författare)
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Elimination/Mitigation of Output Voltage Harmonics for Multilevel Converters Operated at Fundamental Switching Frequency using Matlab's Genetic Algorithm Optimization
- 2020
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Ingår i: 2020 22nd European Conference on Power Electronics and Applications, EPE 2020 ECCE Europe. ; , s. 1-12
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the optimization of the output voltage waveform of a multilevel converter operated with fundamental frequency switching. For a high number of output voltage levels, nearest-level control is typically used, whereas an optimized waveform can be presumably used to eliminate a selection of low order harmonics. A nonlinear optimization problem for any kind of multilevel inverter, operating in a single or three-phase arrangement, is formulated. It is shown that the set of nonlinear equations, defining this optimization problem, cannot be numerically solved, if the number of output voltage levels is higher than nine. Thus, an optimization algorithm, e.g., Matlab's genetic algorithm, should be used instead. Based on the concept of the weighted THD, it is shown that an optimized waveform has no effect on the output current's quality of a single phase multilevel converter. However, considering an ungrounded three-phase system, the content of the to be eliminated harmonic components is shifted towards the triplen harmonics and, consequently, the expected current quality, based on the WTHD, can be significantly improved.
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| 4. |
- Wolf, D., et al.
(författare)
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Late Quaternary fluvial dynamics of the Jarama River in central Spain
- 2013
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Ingår i: Quaternary International. - : Elsevier BV. - 1040-6182. ; 302, s. 20-41
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Tidskriftsartikel (refereegranskat)abstract
- The Jarama River and its catchment provide a valuable natural archive to study and reconstruct past environmental conditions in central Spain. This region is highly prone to changes in the hydrological cycle under predicted climate warming in particular with respect to aridity periods, rainfall variability and the occurrence of extreme flood events. This paper presents 15 exposures covering a time span of the last 44 ka, which were documented in the field and of which seven exposures were soil-chemical analyzed regarding soil texture, organic matter, as well as carbonate and iron content. Ages are based on radiocarbon dating on 32 samples. Latest Holocene sediments were found within the channel-belt, where permanent remobilization of sediments takes place due to the migration of the meandering river course. In more distal floodplain positions, sediment sequences show a complex fluvial architecture referring to periods of varying character and intensity of alluviation as well as periods of geomorphic stability indicated by soil formation. Furthermore, sedimentation patterns vary along different river sections. Aggradations of coarse gravels took place between similar to 40 and 18 ka cal BP over the entire valley floor. Alluviation of fine material was documented between 17 and 16, at similar to 7.5, between 5.1 and 3.3, at 2.8, between 2.1 and 1.5, at similar to 1.0, and around 0.4 ka cal BP until recent times. Astonishingly in late Holocene times, between 4.2 and 3.1 ka cal BP, aggradations of coarse gravels even in distal floodplain areas overlap with sedimentation of fine material in adjacent river sections pointing to a complex constellation of parameters involved. Periods of soil formation were detected around 43, at 31, between 16 and 12.6, after 7.5 until 5.1, between 2.8 and 2.1 and at times after 1.5 ka cal BP. Phases of geomorphic stagnation were found at 38 ka cal BP and for a duration of 200 years at 3.0 ka cal BP and refer to absent geomorphic or pedogenic processes. All these patterns are an expression of the interaction between climatic variations, tectonic impulses and human influences. A comparison with other terrestrial archives enabled us to reconstruct late Pleistocene and Holocene palaeoenvironmental conditions on a regional scale, and furthermore to link specific stages of floodplain development to prevalent influencing variables. Thus, with emphasis on the fluvial system response, a model of a cause and effect relationship is presented, that concentrates on rapid climate changes, long-lasting climatic deteriorations and the role of human interventions. (C) 2013 Elsevier Ltd and INQUA. All rights reserved.
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| 5. |
- Stroikin, Yuri, 1971-
(författare)
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Ageing-associated changes of lysosomal compartment : implications on cellular functions
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The lysosomal compartment is a major site for intracellular degradation. Lysosomal degradation of the cell’s own constituents, so-called autophagy, not only provides a cell with nutrients, but also removes damaged and potentially dangerous endogenous structures, thus securing intracellular homeostasis. On the other hand, lysosomes have been shown to be involved in the initial stages of apoptosis, and the protective effect of autophagy has been suggested to switch to cell death when excessive.Ageing-related changes of cellular structures result from damage caused by eactive oxygen species (ROS), which are an inevitable by-product of aerobic life. Intracellular turnover of compromised organelles and macromolecules, to which lysosomal degradation is a major contributor, does not function perfectly, even under favourable conditions. This inherent incompleteness of lysosomal degradation is responsible for the accumulation of a variety of nondegraded and functionally inefficient structures, which can be considered biological “garbage”. Biological “garbage” includes damaged non-degraded macromolecules and organelles, as well as intralysosomal non-degradable polymer-like structure called lipofuscin, or age pigment. Although accumulation of biological “garbage” has been suggested harmful, little is known about the mechanisms of its deleterious effects.To gain a better understanding of ageing-related changes of the lysosomal compartment and their influence on cell functions, we focused on studying: (1) the role of macroautophagy in the turnover of organelles and lipofuscin formation; (2) the role of biological “garbage” accumulation in the development of ageing-related changes and eventual death of growth-arrested, postmitotic-like cells; (3) the possible cell-protective effect of mitosis; (4) the influence of lipofuscin on cell survival during complete starvation; and (5) the effects of lipofuscin on lysosomal stability.As a model of induced biological “garbage” accumulation we used confluent human fibroblasts treated with the autophagy inhibitor 3-methyladenine (3MA). Alternatively, lysosomal degradation was suppressed by using the cysteine protease inhibitor leupeptin, or the cathepsin D inhibitor pepstatin A. As a cellular model of aged cells, we used lipofucsin-loaded human fibroblasts. Lipofuscin-loading was achieved by culturing confluent fibroblasts under hyperoxic conditions for 2-4 months. Using these in vitro models, the present study shows that: (1) inhibition of autophagy results in accumulation of lysosome-associated autofluorescent material and mitochondria with low membrane potential; (2) detrimental effect of biological “garbage” accumulation following inhibition of autophagy is prevented by continuous cell division; (3) lipofuscin-loaded cells are more resistant to starvation-induced cell death than control cells; (4) lysosomes of lipofuscinloaded fibroblasts are more resistant to the organelle-targeted stress then lysosomes of control cells.Based on the results of the present study we conclude that properly operating autophagic machinery plays a crucial role in preventing age-related changes associated with accumulation of biological “garbage”. We also suggest that continual proliferation is the natural mechanism by which cells cope with the accumulation of non-degradable material, employing mechanical dilution during the cell division. Finally, we introduce an idea of lipofuscin being a hormetic agent, and possibly possessing some lysosome-stabilising properties. Better understanding of the influence of the age-related accumulation of biological “garbage” on cellular functions may be helpful for future development of anti-ageing therapy and management of age-associated pathologies.
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