32 research outputs found

    Obesity resistant mechanisms in the Lean polygenic mouse model as indicated by liver transcriptome and expression of selected genes in skeletal muscle

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    <p>Abstract</p> <p>Background</p> <p>Divergently selected Lean and Fat mouse lines represent unique models for a polygenic form of resistance and susceptibility to obesity development. Previous research on these lines focused mainly on obesity-susceptible factors in the Fat line. This study aimed to examine the molecular basis of obesity-resistant mechanisms in the Lean line by analyzing various fat depots and organs, the liver transcriptome of selected metabolic pathways, plasma and lipid homeostasis and expression of selected skeletal muscle genes.</p> <p>Results</p> <p>Expression profiling using our custom Steroltalk v2 microarray demonstrated that Lean mice exhibit a higher hepatic expression of cholesterol biosynthesis genes compared to the Fat line, although this was not reflected in elevation of total plasma or liver cholesterol. However, FPLC analysis showed that protective HDL cholesterol was elevated in Lean mice. A significant difference between the strains was also found in bile acid metabolism. Lean mice had a higher expression of <it>Cyp8b1</it>, a regulatory enzyme of bile acid synthesis, and the <it>Abcb11 </it>bile acid transporter gene responsible for export of acids to the bile. Additionally, a higher content of blood circulating bile acids was observed in Lean mice. Elevated HDL and upregulation of some bile acids synthesis and transport genes suggests enhanced reverse cholesterol transport in the Lean line - the flux of cholesterol out of the body is higher which is compensated by upregulation of endogenous cholesterol biosynthesis. Increased skeletal muscle <it>Il6 </it>and <it>Dio2 </it>mRNA levels as well as increased activity of muscle succinic acid dehydrogenase (SDH) in the Lean mice demonstrates for the first time that changes in muscle energy metabolism play important role in the Lean line phenotype determination and corroborate our previous findings of increased physical activity and thermogenesis in this line. Finally, differential expression of <it>Abcb11 </it>and <it>Dio2 </it>identifies novel strong positional candidate genes as they map within the quantitative trait loci (QTL) regions detected previously in crosses between the Lean and Fat mice.</p> <p>Conclusion</p> <p>We identified novel candidate molecular targets and metabolic changes which can at least in part explain resistance to obesity development in the Lean line. The major difference between the Lean and Fat mice was in increased liver cholesterol biosynthesis gene mRNA expression, bile acid metabolism and changes in selected muscle genes' expression in the Lean line. The liver <it>Abcb11 </it>and muscle <it>Dio2 </it>were identified as novel positional candidate genes to explain part of the phenotypic difference between the Lean and Fat lines.</p

    Towards harmonization of forest deposition collectors - case study of comparing collector designs

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    In recent years the harmonization of methods in the frame of the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) operating under the UNECE Convention on Long-range Transboundary Air Pollution (CLRTAP) has been intensified. Among the C-actions of the FutMon project (LIFE07 ENV/D/000218; 2009-2010) the C1-Dep-22(SI) action was established with the goal to harmonize and develop the deposition monitoring procedures and sampling methods. The sampling equipment, spatial design of sampling plots and sampling frequency throughout Europe vary considerably. Therefore a step-by-step approach was made where the harmonized sampling equipment was developed and tested first. The selected collectors were installed at one observation plot of each participating country where measurements of throughfall and bulk deposition were run in parallel with the national collectors for a period of one year. To evaluate the agreement between methods, different statistical analyses were used including Altman-Bland plots, model II regression, and repeated measures ANOVA. Preliminary results from the “Intensive forest ecosystem monitoring plot” plot Brdo in NW Slovenia show a good agreement between national and harmonized bulk (both funnel-type) collectors, while comparison of throughfall measurements indicates systematic bias between harmonized (funnel-type) and national (gutter-type) collectors

    Model symulacyjny odwijania przędzy z nawoju

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    Yarn unwinding from packages plays an essential role in many textile processes. The stability of unwinding has a direct influence on the efficiency of the textile processes in general and on the quality of the final products. Calculations based on a theoretical model of unwinding can help us in our pursuit of an optimal design of packages and an optimal unwinding process. We will derive expressions for the time dependence of the angular velocity of the balloon rotation around the package axis, of the unwinding velocity and the winding angle during yarn unwinding from the cylindrical package. We will demonstrate a mathematical model for simulating the unwinding from cylindrical packages. We will show how the winding angle influences the angular velocity and tension oscillations of the yarn during unwinding. Since the centrifugal forces on the yarn in the balloon depend on the angular velocity, this velocity has a large influence on the tension that we wish to reduce.Odwijanie przędzy z nawoju odgrywa kluczową rolę w wielu procesach włókienniczych. Stabilność odwijania ma bezpośredni wpływ na efektywność procesów włókienniczych i na jakość produktów końcowych. Obliczenia oparte na modelu teoretycznym odwijania są pomocne w projektowaniu nawojów i optymalizacji procesu odwijania. Wyprowadzono zależności czasowe prędkości kątowej wirowania balonu wokół osi nawoju i prędkości odwijania oraz wzór na kąt przewijania. Przedstawiono matematyczny model symulacji odwijania z awojów cylindrycznych. Pokazano jak wpływa kąt przewijania na prędkość kątową i wahania naprężenia podczas odwijania przędzy

    Predicting phenology of European beech in forest habitats

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    Reliable phenological observations are important for studying the response of trees to climate and climate change. National phenological networks were not specifically established to monitor tree phenology within forests, yet they are often used to generalise tree phenological phases at national or regional scales. Our objective was to investigate whether a phenological monitoring network using trees in open areas can accurately predict phenology of European beech (Fagus sylvatica L.) located within forests by using two models: one with correlates of environmental variables and one with interpolated monthly air temperature and sun hours. The first leaf unfolding, general leaf colouring and leaf fall dates from 2004 through 2010 were modelled using data from 47 Slovene National Phenology Network (NPN) stations in open areas and tested on phenological observations within forests using data from the UNECE CRLTAP ICP Forests network. Good agreement was found between predicted and observed first leaf unfolding in the forest, while slightly lower agreement was detected for general leaf colouring and leaf fall. Suggestions for the improvement of national phenological network are discussed in order to better predict beech phenology in forest habitats

    Predicting phenology of European beech in forest habitats

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