Optical microrheology using rotating laser-trapped particles

We demonstrate an optical system that can apply and accurately measure the torque exerted by the trapping beam on a rotating birefringent probe particle. This allows the viscosity and surface effects within liquid media to be measured quantitatively on a micron-size scale using a trapped rotating spherical probe particle. We use the system to measure the viscosity inside a prototype cellular structure.Comment: 5 pages, 4 figures. v2: bibliographic details, minor text correction

Long-time discrete particle effects versus kinetic theory in the self-consistent single-wave model

The influence of the finite number N of particles coupled to a monochromatic wave in a collisionless plasma is investigated. For growth as well as damping of the wave, discrete particle numerical simulations show an N-dependent long time behavior resulting from the dynamics of individual particles. This behavior differs from the one due to the numerical errors incurred by Vlasov approaches. Trapping oscillations are crucial to long time dynamics, as the wave oscillations are controlled by the particle distribution inhomogeneities and the pulsating separatrix crossings drive the relaxation towards thermal equilibrium.Comment: 11 pages incl. 13 figs. Phys. Rev. E, in pres

Adaptability of irrigated spring canola oil production to the US High Plains

Canola oil is high in oleic acid which is commonly used for food and industrial purposes. To determine adaptability of spring canola (Brassica napus L.) to the High Plains for industrial oil production, 26 irrigated trials were conducted from 2005 to 2008. Trials were divided into five regions—1: 36–37◦N 108◦W; 2: 39–40◦N 101–103◦W; 3: 41–42◦N 102–103◦W; 4: 41–42◦N 104◦W; 5: 43–44◦N 106–108◦W. Cultural practices were based on site-specific protocols. Four cultivars, Hyola 401, Hyola 357 Magnum, SW Marksman, and SW Patriot, were planted in replicated plots in April or May under standard irrigation and harvested in July to October depending on region. Seed yield Hyola 401 and Hyola 357 Magnum were higher than SW Marksman and SW Patriot across the five regions and within Regions 1, 2, 3, and 5. Regions 1, 2 and 3 yielded significantly greater than did Regions 4 and 5. Samples from 18 trials were examined for their oil content and fatty acid distribution. The four cultivars had greater than 38% oil content; SW Marksman and SW Patriot had higher oil content than Hyola 401 and Hyola 357 Mag. Higher oil content was achieved in Regions 1, 4 and 5. Across and within regions, the percent of oleic acid did not differ for the four cultivars. The mean content of oleic acid decreased going north from Region 2 to Region 5, as did seed yield in the High Plains. Linoleic acid increased going north from Region 1. Linolenic acids showed little variation across regions. Considering yield and total oil content together, growing spring canola would be excellent in the High Plains

Adaptability of irrigated spring canola oil production to the US High Plains

Canola oil is high in oleic acid which is commonly used for food and industrial purposes. To determine adaptability of spring canola (Brassica napus L.) to the High Plains for industrial oil production, 26 irrigated trials were conducted from 2005 to 2008. Trials were divided into five regions—1: 36–37◦N 108◦W; 2: 39–40◦N 101–103◦W; 3: 41–42◦N 102–103◦W; 4: 41–42◦N 104◦W; 5: 43–44◦N 106–108◦W. Cultural practices were based on site-specific protocols. Four cultivars, Hyola 401, Hyola 357 Magnum, SW Marksman, and SW Patriot, were planted in replicated plots in April or May under standard irrigation and harvested in July to October depending on region. Seed yield Hyola 401 and Hyola 357 Magnum were higher than SW Marksman and SW Patriot across the five regions and within Regions 1, 2, 3, and 5. Regions 1, 2 and 3 yielded significantly greater than did Regions 4 and 5. Samples from 18 trials were examined for their oil content and fatty acid distribution. The four cultivars had greater than 38% oil content; SW Marksman and SW Patriot had higher oil content than Hyola 401 and Hyola 357 Mag. Higher oil content was achieved in Regions 1, 4 and 5. Across and within regions, the percent of oleic acid did not differ for the four cultivars. The mean content of oleic acid decreased going north from Region 2 to Region 5, as did seed yield in the High Plains. Linoleic acid increased going north from Region 1. Linolenic acids showed little variation across regions. Considering yield and total oil content together, growing spring canola would be excellent in the High Plains

Abelian symmetries in multi-Higgs-doublet models

N-Higgs doublet models (NHDM) are a popular framework to construct electroweak symmetry breaking mechanisms beyond the Standard model. Usually, one builds an NHDM scalar sector which is invariant under a certain symmetry group. Although several such groups have been used, no general analysis of symmetries possible in the NHDM scalar sector exists. Here, we make the first step towards this goal by classifying the elementary building blocks, namely the abelian symmetry groups, with a special emphasis on finite groups. We describe a strategy that identifies all abelian groups which are realizable as symmetry groups of the NHDM Higgs potential. We consider both the groups of Higgs-family transformations only and the groups which also contain generalized CP transformations. We illustrate this strategy with the examples of 3HDM and 4HDM and prove several statements for arbitrary N.Comment: 33 pages, 2 figures; v2: conjecture 3 is proved and becomes theorem 3, more explanations of the main strategy are added, matches the published versio

The glucocorticoid dexamethasone inhibits HIF-1α stabilization and metabolic reprogramming in lipopolysaccharide-stimulated primary macrophages

Synthetic glucocorticoids are used to treat many chronic and acute inflammatory conditions. Frequent adverse effects of prolonged exposure toglucocorticoids include disturbances of glucose homeostasis caused by changes in glucose traffic and metabolism in muscle, liver, and adiposetissues. Macrophages are important targets for the anti-inflammatory actions of glucocorticoids. These cells rely on aerobic glycolysis to supportvarious pro-inflammatory and antimicrobial functions. Employing a potent pro-inflammatory stimulus in two commonly used model systems(mouse bone marrow-derived and human monocyte-derived macrophages), we showed that the synthetic glucocorticoid dexamethasone inhib-ited lipopolysaccharide-mediated activation of the hypoxia-inducible transcription factor HIF-1α, a critical driver of glycolysis. In both cell types,dexamethasone-mediated inhibition of HIF-1α reduced the expression of the glucose transporter GLUT1, which imports glucose to fuel aerobicglycolysis. Aside from this conserved response, other metabolic effects of lipopolysaccharide and dexamethasone differed between human andmouse macrophages. These findings suggest that glucocorticoids exert anti-inflammatory effects by impairing HIF-1α-dependent glucose uptakein activated macrophages. Furthermore, harmful and beneficial (anti-inflammatory) effects of glucocorticoids may have a shared mechanisticbasis, depending on the alteration of glucose utilization

Do low surface brightness galaxies have dense disks?

The disk masses of four low surface brightness galaxies (LSB) were estimated using marginal gravitational stability criterion and the stellar velocity dispersion data which were taken from Pizzella et al., 2008 [1]. The constructed mass models appear to be close to the models of maximal disk. The results show that the disks of LSB galaxies may be significantly more massive than it is usually accepted from their brightnesses. In this case their surface densities and masses appear to be rather typical for normal spirals. Otherwise, unlike the disks of many spiral galaxies, the LSB disks are dynamically overheated.Comment: 14 pages, 10 figures, submitted to Astronomy Report

On Ruelle's construction of the thermodynamic limit for the classical microcanonical entropy

In this note we make a very elementary technical observation to the effect that Ruelle's construction of the thermodynamic limit of the classical entropy density defined with a regularized microcanonical measure actually establishes the thermodynamic limit for the entropy density defined with the proper microcanonical measure. At this stage a key formula is still derived from the regularized measures. We also show that with only minor changes in the proof the regularization of the microcanonical measure is actually not needed at all.Comment: Short communication (7p), accepted for publication in J.Stat.Phy