Le point principal de cette étude est l'existence du moment cinétique de Casimir d'un point de vue microscopique, montrée à l'aide d'un modèle comprenant un oscillateur harmonique soumis à des champs ...électrique et magnétique externes, croisés, homogènes de façon à obtenir les propriétés d'un milieu bi-anisotrope, en interaction avec les fluctuations quantiques du vide. Nous avons donné un ordre de grandeur de la vitesse de l'oscillateur attendue pour des conditions expérimentales raisonnables. Nous trouvons une contribution classique due aux champs externes de l'ordre de 0,1 micromètre par seconde et une contribution quantique attribuée aux fluctuations du vide de l'ordre de 2 nanomètre par seconde. Dans le cas d'un atome d'hydrogène en mouvement, où la bi-anisotropie est due à l'effet Fizeau, nous trouvons que l'effet du couplage avec le vide donne une correction de masse en accord avec le principe d'équivalence masse-énergie d'Einstein, à température nulle ou non-nulle. Dans le cas de deux atomes en mouvement dans le vide, nous donnons la marche à suivre dans le but de montrer que l'énergie de Casimir entre les deux atomes, c'est-à-dire liée aux forces de Van der Waals, participe de la même façon à la masse inertielle de l'ensemble. Cette approche confirme que le moment de Casimir n'est pas exclu voire même réclamé par les principes de la relativité restreinte. Nous nous sommes intéressés au cas de l'énergie Casimir d'une boule diélectrique diluée. Un calcul numérique de l'énergie associée aux forces de Van der Waals, dont l'équivalence avec l'énergie de Casimir a été montrée par ailleurs, nous a permis de déterminer l'énergie totale de la boule en fonction de son rayon. Nous déterminons les termes associés à la chaleur latente et à la tension de surface. Nous trouvons ensuite un terme variant de façon linéaire avec le rayon, en désaccord avec les méthodes de renormalisation utilisées avec une description continue. Ce désaccord est expliqué par la description continue de la matière où les interactions à courte distance sont surévaluées et conduisent à des termes divergents non considérés par la renormalisation.
The effect of dietary linseed and lucerne supplementation on the oxidative stability of ostrich meat expressed by changes in concentrations of malondialdehyde (MDA) and glutathione (GSH), and in ...activity of superoxide dismutase (SOD), was studied. The feeding regimens were as follows: C – control group, L – 4% supplement of linseed, L-L45, L-L55, L-L65, and L-L75 – 4% supplement of linseed and supplement of lucerne added to the birds’ diet at 45, 55, 65, and 75 kg b.w. The highest level of GSH was recorded in L-L65 group, whereas the highest activity of SOD was observed in C, L-L65 and L-L75 groups. Among all groups, the long-term linseed and lucerne supplementation reduced the antioxidant potential of ostrich meat, especially in L-L45 and L-L55 groups, which was reflected in the highest level of MDA and the lowest activity of SOD. Thus, the optimal results after linseed and lucerne supplementation with regard to ostrich meat oxidative stability were reported in groups L-L65 and L-L75, approximately three to four months prior to slaughter.
As building control surveyors they all understand the benefits of achieving a chartered status with RICS. It is impressed on them through the education, and as graduates with accredited degrees they ...know that it plays a major part in career progression within the industry. The author graduated from the University of Westminster in 2003 and joined a local authority in London that year as a building control surveyor. A good support network is essential to achieving a chartered status with RICS. However, it is essentially down to the individual to set themselves targets, arrange regular meetings with their supervisor and counsellor and to carry out a lot of research in their own time. Key to success is choosing the right project/s for your critical analysis. Presenting the issues you faced and the solutions you considered/adopted is the most direct way of demonstrating a Level 3 achievement.
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Eight subjects (20.6 ± 2.1 yr; 81.4 ± 9.8 kg) performed 300 isolateral eccentric contractions (knee extensions at 180 °/s) to evaluate the skeletal muscle satellite cell (SC) response ...and the potential of hepatocyte growth factor (HGF) signaling in mediating SC activation and proliferation following acute damaging exercise. Muscle biopsies were obtained from the vastus lateralis of the non‐exercised leg prior to exercise (PRE) and the exercised leg at 4 (T4), 24 (T24), 72 (T72), and 120 h (T120) post‐exercise. The number of SC (N‐CAM
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) increased (p < 0.001) by T4 and remained elevated at T120 (p = 0.002). Serum HGF increased at T4 (p < 0.05) with a trend for increased muscle HGF and HGF activator (HGFA) protein expression at T24 with active HGF detected in all PRE samples. HGFA inhibitors (HAI‐1 and HAI‐2) protein content increased at T72 and remained elevated at T120 (p < 0.05). Myogenic regulatory factors (MyoD and Myf5) mRNA expression increased at T4 and T24 (p < 0.05) respectively, with increased myogenin mRNA expression at T24 (p < 0.05). Furthermore, plasma interleukin‐6 concentration increased ∼200% (p < 0.05) by T4, illustrating a roll of both local and systemic signaling in the activation and proliferation of SC; with HGF signaling playing an important regulatory role in the SC response to exercise‐induced muscle damage.
Supported by NSERC
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
On semiconductor growth surfaces, surface reconstructions appear. Estimation of the reconstructed structures is essential for understanding and controlling growth phenomena. In this study, the ...stability of a mixture of two different surface reconstructions is investigated. Since the number of candidate structures is enormous, the structures sampled by Bayesian optimization are analyzed. As a result, the local electron counting (EC) rule alone was found to be insufficient to explain such stability. Then, augmenting the EC rule, a data-driven Ising model is proposed. The model allows the evaluation of the whole enormous number of candidate structures. The approach is expected to be useful for theoretical studies of such mixtures on various semiconductor surfaces.
It has been recently suggested that white dwarfs generate magnetic fields in a process analogous to the Earth. The crystallization of the core creates a compositional inversion that drives ...convection, and combined with rotation, this can sustain a magnetic dynamo. We reanalyse the dynamo mechanism, arising from the slow crystallization of the core, and find convective turnover times \(t_{\rm conv}\) of weeks to months - longer by orders of magnitude than previously thought. With white dwarf spin periods \(P\ll t_{\rm conv}\), crystallization-driven dynamos are almost always in the fast rotating regime, where the magnetic field \(B\) is at least in equipartition with the convective motion and is possibly further enhanced by a factor of \(B\propto (t_{\rm conv}/P)^{1/2}\), depending on the assumed dynamo scaling law. We track the growth of the crystallized core using MESA and compute the magnetic field \(B(T_{\rm eff})\) as a function of the white dwarf's effective temperature \(T_{\rm eff}\). We compare this prediction with observations and show that crystallization-driven dynamos can explain some - but not all - of the \(\sim\)MG magnetic fields measured for single white dwarfs, as well as the stronger fields measured for white dwarfs in cataclysmic variables, which were spun up by mass accretion to short \(P\). Our \(B(T_{\rm eff})\) curves might also explain the clustering of white dwarfs with Balmer emission lines around \(T_{\rm eff}\approx 7500\textrm{ K}\).
We aimed to assess the clinical efficacy of glucose-insulin-potassium (GIK) in acute myocardial infarction. Experimental data provided evidence of the beneficial effects of GIK on ischemic ...myocardium. The clinical trials, mostly uncontrolled and conducted mainly before the thrombolytic era, were inconclusive due to the small number of patients and discrepancies in protocols. In order to evaluate the efficacy of this intervention, we have performed a prospective multicenter randomized study. The study consisted of 954 patients with acute myocardial infarction (MI) randomized within 24 hours from the onset of symptoms to low-dose GIK (n = 494), which consisted of 1000 mL 10% dextrose, 32-20 U insulin, and 80 mEq K-, or to the control group (n = 460), which was given 1000 mL 0.89% sodium chloride, by intravenous 24-hour infusion at a rate of 42 mL/h. Cardiac mortality and the occurrence of cardiac events at 35 days did not differ between GIK and control-allocated patients (32 (6.5%) vs. 21 (4.6%), respectively; OR 1.45, 95% CI 0.79-2.68, P = 0.20; and 214 (43.3%) vs. 192 (41.7%), OR 1.07, 95% CI 0.82-1.38, P = 0.62). Total mortality at 35 days was significantly higher in the GIK than in the control group (44 (8.9%) vs. 22 (4.8%), respectively, OR 1.95, 95% CI 1.12-3.47, P = 0.01). The excess of non-cardiac deaths in the GIK group may have occurred by chance. Low-dose GIK treatment does not improve the survival and clinical course in acute MI.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We present an analysis of spectroscopic data of the cool, highly magnetic and polluted white dwarf 2MASS J0916-4215. The atmosphere of the white dwarf is dominated by hydrogen, but numerous spectral ...lines of magnesium, calcium, titanium, chromium, iron, strontium, along with Li I, Na I, Al I, and K I lines, are found in the incomplete Paschen-Back regime, most visibly, in the case of Ca II lines. Extensive new calculations of the Paschen-Back effect in several spectral lines are presented and results of the calculations are tabulated for the Ca II H&K doublet. The abundance pattern shows a large lithium and strontium excess, which may be viewed as a signature of planetary debris akin to Earth's continental crust accreted onto the star, although the scarcity of silicon indicates possible dilution in bulk Earth material. Accurate abundance measurements proved sensitive to the value of the broadening parameter due to collisions with neutral hydrogen (Gamma_HI), particularly in saturated lines such as the resonance lines of Ca I and Ca II. We found that Gamma_HI if formulated with values from the literature could be overestimated by a factor of 10 in most resonance lines.
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