256 research outputs found

    Fysisk prestation och matchkrav inom elitfotboll - Samband mellan smålagsspel och de mest intensiva perioder inom fotboll

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    De fysiska kraven hos elitfotbollsspelare är stora och såväl aerob som anaerob förmåga är viktiga för prestationen. Individuella skillnader i fysisk kapacitet spelare emellan är välkänt men individuell träningsplanering med lämplig belastning för att optimera spelares enskilda behov är inte lika väl studerat. Syftet med denna studie är att undersöka sambandet mellan spelares matchkrav i fotboll i form av högintensiva perioder (peakperioder) och träningsrespons på smålagsspel. Vi har studerat individuella spelares högintensiva perioder i match, olika typer av smålagsspel (4v4, 6v6 och 8v8) och andra fysiska tester. Studien har en kvantitativ experimentell design där GPS-data i fotboll är analyserad. 17 elitfotbollsspelare (Ålder 23.7 ± 4.8 år, vikt 76.4 ± 4.8 kg, längd 181.1 ± 5.2 cm) från allsvenskan och superettan i svensk herrfotboll deltog i studien. Resultaten visar att olika typer av smålagsspel belastar spelarna på olika sätt, där vissa fysiska variabler har ett medel (>0.30) till stark korrelation (>0.70), medan andra variabler visar en svag (>0.10) till ingen korrelation (<0.10). Sambandet mellan fysiska tester och matchkrav i form av peakperioder visar att endast Repeated Sprint Ability (RSA) kan ha en relevant användning för att förutse prestation i peakperioder. Information om vilken typ av smålagsspel som har vilken effekt och hur de belastar spelaren samt matchkrav på individ- och gruppnivå kan underlätta för tränaren vid utformning av träningsplanering. Slutligen krävs mer forskning inom området för att säkerhetsställa att tillämpningen av smålagsspel samt de fysiska testerna, gentemot matchkraven i form av peakperioder, blir så matchlik och optimal som möjligt

    Determination of the gamma emission probabilities of 239

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    239Np is an important nuclide as the decay daughter of 239U and it decays to 239Pu by emitting beta particles and gamma rays with a half life of 2.356 days. The data of the emission probabilities of its gamma-rays in the open references are consistent except for the main gamma-ray of 106.1 keV, the emission probability of which varies from 25.9% to 27.2%. To verify the emission probability of 106.1 keV gamma-ray of 239Np, a N-type coaxial HPGe detector was calibrated using 241Am, 133Ba, 60Co, 152Eu and 155Eu reference gamma sources to get the accurate efficiency of the 106.1 keV gamma-ray. 239Np was purified from solution containing 243Am, where 239Np is the alpha decay daughter of 243Am. The specific activity of 239Np solution was determined by a 4πβ (PC)-γ coincidence counting device. There were 6 gamma sources prepared to measure with the HPGe detector, and the activity of 239Np in each gamma source was calculated with the weights of the solution contained in it. The emission probability of 106.1 keV of 239Np is measured to be (25.4 ± 0.3)%, which is consistent with 25.34%, the value evaluated in 2014

    Hydrophobically associating polymers for enhanced oil recovery – Part B: A review of modelling approach to flow in porous media

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    Polymer flow in porous media represents an entirely different scenario compared to bulk flow analysis using viscometers. This is due to the geometry and configuration of the medium which is made up of converging-diverging flow paths. In this article, a review of the single-phase flow of hydrophobically associating polymers in porous media is presented. Hydrophobic association between these polymer chains have been reported to occur and vary under reservoir conditions (temperature, salinity, and ion concentration). However, under these conditions, the critical aggregation concentration of associating polymers has been observed to change and the extent of change is a function of the hydrophobe make-up of the polymer. The outcome of this would indicate that polymer injectivity and its oil recovery efficiency are affected. As such, an understanding of the mechanism, propagation and sustainability of these hydrophobic interactions in reservoirs remains a critical focus of research. This becomes even imperative as the in-situ rheological profile associated with the different flow regimes may be affected. A numerical approach to investigating the real-time hydrophobic interactions between associating polymer chains during flow in porous media remains the viable option. However, this would require modifying existing time-independent models to accurately predict the various flow regimes and the dispersion of associating polymers to account for hydrophobic interactions

    Review of phase change emulsions (PCMEs) and their applications in HVAC systems

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    Phase change material emulsions (PCMEs) are multifunctional fluids consisting of phase change materials (PCMs) and carrier fluids. PCMEs could be potential candidates as heat transfer media in heating, ventilation and air conditioning (HVAC) systems. This is mainly because PCME could take advantage of its high heat capacity to reduce flow rate and thus saving pumping power whilst delivering the same amount of cooling effect. PCME can also simultaneously act as cold storage to shift peak-load to off-peak time and improve the COP of systems. However, the optimum design of integrated system requires a good understanding of flow behaviour and heat transfer characteristics of PCMEs. In this paper, comprehensive reviews of their thermo-physical properties and potential applications as thermal energy storage and as alternative heat transfer fluids in air conditioning systems have been carried out to establish their limitations for future research

    Wolfberry genomes and the evolution of Lycium (Solanaceae)

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    AbstractWolfberry Lycium, an economically important genus of the Solanaceae family, contains approximately 80 species and shows a fragmented distribution pattern among the Northern and Southern Hemispheres. Although several herbaceous species of Solanaceae have been subjected to genome sequencing, thus far, no genome sequences of woody representatives have been available. Here, we sequenced the genomes of 13 perennial woody species of Lycium, with a focus on Lycium barbarum. Integration with other genomes provides clear evidence supporting a whole-genome triplication (WGT) event shared by all hitherto sequenced solanaceous plants, which occurred shortly after the divergence of Solanaceae and Convolvulaceae. We identified new gene families and gene family expansions and contractions that first appeared in Solanaceae. Based on the identification of self-incompatibility related-gene families, we inferred that hybridization hotspots are enriched for genes that might be functioning in gametophytic self-incompatibility pathways in wolfberry. Extremely low expression of LOCULE NUBER (LC) and COLORLESS NON-RIPENING (CNR) orthologous genes during Lycium fruit development and ripening processes suggests functional diversification of these two genes between Lycium and tomato. The existence of additional flowering locus C-like MADS-box genes might correlate with the perennial flowering cycle of Lycium. Differential gene expression involved in the lignin biosynthetic pathway between Lycium and tomato likely illustrates woody and herbaceous differentiation. We also provide evidence that Lycium migrated from Africa into Asia, and subsequently from Asia into North America. Our results provide functional insights into Solanaceae origins, evolution and diversification.</jats:p

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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