Dynamic Response of a fast near infra-red Mueller matrix ellipsometer

The dynamic response of a near infrared Ferroelectric Liquid Crystal based Mueller matrix ellipsometer (NIR FLC-MME) is presented. A time dependent simulation model, using the measured time response of the individual FLCs, is used to describe the measured temporal response. Furthermore, the impulse response of the detector and the pre-amplifier is characterized and included in the simulation model. The measured time-dependent intensity response of the MME is reproduced in simulations, and it is concluded that the switching time of the FLCs is the limiting factor for the Mueller matrix measurement time of the FLC-based MME. Based on measurements and simulations our FLC based NIR-MME system is estimated to operate at the maximum speed of approximately 16 ms per Mueller matrix measurement. The FLC-MME may be operated several times faster, since the switching time of the crystals depends on the individual crystal being switched, and to what state it is switched. As a demonstration, the measured temporal response of the Mueller matrix and the retardance of a thick liquid crystal variable retarder upon changing state is demonstrated.Comment: to be published in Journal of Modern Optics 20 pages, 6 figure

Biodegradation of some agricultural residues by fungi in agitated submerged cultures

Digestibility of agricultural residues in animal feeding is deeply dependent on the amounts and types of their fibers. Biological treatment of agricultural residues is a new method for improvement of digestibility. Therefore, the capacity of a few fungi in biodegradation of some agricultural residues wasstudied. Losses of crude fiber (CF), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of wheat, barley, rice, wood, and pea straw were investigated in agitated submerged culture during biodegradation by fungi. Biodegradation of the plant residues is dependent on the plant and fungusspecies. The biodegradation order of plant residues was  pea>barley>wheat>rice>wood. A. terreus and T. reesei were more able to degrade the easy degradable plant residues. Rice and wood were degradedmore by Armillaria sp., Polyporus sp. and P. chrysosporium. Crude fiber, NDF and ADF of agricultural residues were reduced more by P. chrysosporium. Generally, the reduction of agricultural residues NDF by fungi was more than their ADF. However, Polyporus sp. decreased ADF of wheat straw more. Thus, for improvement of digestibility of agricultural residues, the treatment by white-rot fungi may be recommended

Metabolic switching of human skeletal muscle cells in vitro

In this review we will focus on external factors that may modify energy metabolism in human skeletal muscle cells (myotubes) and the ability of the myotubes to switch between lipid and glucose oxidation. We describe the metabolic parameters suppressibility, adaptability and substrate-regulated flexibility, and show the influence of nutrients such as fatty acids and glucose (chronic hyperglycemia), and some pharmacological agents modifying nuclear receptors (PPAR and LXR), on these parameters in human myotubes. Possible cellular mechanisms for changes in these parameters will also be highlighted.The present work was funded by University of Oslo, The European Nutrigenomics Organisation (NuGO), The Norwegian Diabetes Foundation, AstraZeneca, Freia Chocolade Fabriks Medical Foundation, and The Anders Jahre’s Foundatio

The role of (de-)essentialisation within siting conflicts: an interdisciplinary approach

Large-scale renewable energy and associated technologies (RET), such as high voltage power lines (HVPL), often meet opposition from the local communities living nearby. Research has suggested that one of the main aspects that might contribute to this is the fact that RET are represented as industrial and urban, and thus, as having a different essence from rural landscapes, where they are usually deployed and which are represented as natural and unspoilt. However, this 'hypothesis' of landscape essentialisation shaping people's responses to RET has not been explicitly examined. By drawing upon research from Social Psychology and Human Geography on essentialisation, we will examine if and how landscape (de-)essentialisation plays a role in people's responses to RET. Namely, by examining it as a rhetorical construction that can be strategically used to negotiate and legitimize given relations with place and associated responses to RET.Focus groups were conducted in the UK and Norway with members of local communities to be affected by the construction of HVPLs that will connect to new low carbon energy technologies. Analyses show that participants present British and Norwegian rural landscapes in general and HVPL as having two different essences, which justifies opposition to those infrastructures. However, analyses also show that essentialisation of the countryside is strategically used. Namely, participants also present the countryside in the place where they live as having more of the essence of the British or Norwegian countryside than other areas of the UK and Norway. In turn, this allows them to legitimize claims that whereas HVPL are 'out of place' in the countryside in general, they are more so in the place where they live.The implications of these results for the definition of acceptable locations for RET and for research on people-place relations and responses to place change, are discussed.info:eu-repo/semantics/acceptedVersio

Nuclear structure of Ac-231

The low-energy structure of 231Ac has been investigated by means of gamma ray spectroscopy following the beta-decay of 231Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus

Remodelling of oxidative energy metabolism by galactose improves glucose handling and metabolic switching in human skeletal muscle cells

Cultured human myotubes have a low mitochondrial oxidative potential. This study aims to remodel energy metabolism in myotubes by replacing glucose with galactose during growth and differentiation to ultimately examine the consequences for fatty acid and glucose metabolism. Exposure to galactose showed an increased [14C]oleic acid oxidation, whereas cellular uptake of oleic acid uptake was unchanged. On the other hand, both cellular uptake and oxidation of [14C]glucose increased in myotubes exposed to galactose. In the presence of the mitochondrial uncoupler carbonylcyanide p-trifluormethoxy-phenylhydrazone (FCCP) the reserve capacity for glucose oxidation was increased in cells grown with galactose. Staining and live imaging of the cells showed that myotubes exposed to galactose had a significant increase in mitochondrial and neutral lipid content. Suppressibility of fatty acid oxidation by acute addition of glucose was increased compared to cells grown in presence of glucose. In summary, we show that cells grown in galactose were more oxidative, had increased oxidative capacity and higher mitochondrial content, and showed an increased glucose handling. Interestingly, cells exposed to galactose showed an increased suppressibility of fatty acid metabolism. Thus, galactose improved glucose metabolism and metabolic switching of myotubes, representing a cell model that may be valuable for metabolic studies related to insulin resistance and disorders involving mitochondrial impairments

Are cultured human myotubes far from home?

Satellite cells can be isolated from skeletal muscle biopsies, activated to proliferating myoblasts and differentiated into multinuclear myotubes in culture. These cell cultures represent a model system for intact human skeletal muscle and can be modulated ex vivo. The advantages of this system are that the most relevant genetic background is available for the investigation of human disease (as opposed to rodent cell cultures), the extracellular environment can be precisely controlled and the cells are not immortalized, thereby offering the possibility of studying innate characteristics of the donor. Limitations in differentiation status (fiber type) of the cells and energy metabolism can be improved by proper treatment, such as electrical pulse stimulation to mimic exercise. This review focuses on the way that human myotubes can be employed as a tool for studying metabolism in skeletal muscles, with special attention to changes in muscle energy metabolism in obesity and type 2 diabetes

DNA adducts in fish following an oil spill exposure

On 12 December 1999, one third of the load of the Erika tanker, amounting to about 10,000 t crude oil flowed into sea waters close to the French Atlantic Coast. This oil contained polycyclic aromatic compounds (PAC) that are known to be genotoxic. Genotoxic effects induce DNA adducts formation, which can thus be used as pollution biomarkers. Here, we assessed the genotoxic impact of the “Erika” oil spill by DNA adducts detection in the liver of immature fishes (Solea solea) from four locations of the French Brittany coasts. Two months after the spill, a high amount of DNA adducts was found in samples from all locations, amounting to 92–290 DNA adduct per 109 nucleotides. Then total DNA adduct levels decreased to reach about 50 adducts per 109 nucleotides nine months after the spill. In vitro experiments using human cell cultures and fish liver microsomes evidence the genotoxicity of the Erika fuel. They also prove the formation of reactive species able to create DNA adducts. Furthermore, in vitro and in vivo DNA adducts fingerprints are similar, thus confirming that DNA adducts are a result of the oil spill