Periodic orbit bifurcations and scattering time delay fluctuations

We study fluctuations of the Wigner time delay for open (scattering) systems which exhibit mixed dynamics in the classical limit. It is shown that in the semiclassical limit the time delay fluctuations have a distribution that differs markedly from those which describe fully chaotic (or strongly disordered) systems: their moments have a power law dependence on a semiclassical parameter, with exponents that are rational fractions. These exponents are obtained from bifurcating periodic orbits trapped in the system. They are universal in situations where sufficiently long orbits contribute. We illustrate the influence of bifurcations on the time delay numerically using an open quantum map.Comment: 9 pages, 3 figures, contribution to QMC200

Universal quantum signature of mixed dynamics in antidot lattices

We investigate phase coherent ballistic transport through antidot lattices in the generic case where the classical phase space has both regular and chaotic components. It is shown that the conductivity fluctuations have a non-Gaussian distribution, and that their moments have a power-law dependence on a semiclassical parameter, with fractional exponents. These exponents are obtained from bifurcating periodic orbits in the semiclassical approximation. They are universal in situations where sufficiently long orbits contribute.Comment: 7 page

A Study of Single- and Double-Averaged Second-Order Models to Evaluate Third-Body Perturbation Considering Elliptic Orbits for the Perturbing Body

The equations for the variations of the Keplerian elements of the orbit of a spacecraft perturbed by a third body are developed using a single average over the motion of the spacecraft, considering an elliptic orbit for the disturbing body. A comparison is made between this approach and the more used double averaged technique, as well as with the full elliptic restricted three-body problem. the disturbing function is expanded in Legendre polynomials up to the second order in both cases. the equations of motion are obtained from the planetary equations, and several numerical simulations are made to show the evolution of the orbit of the spacecraft. Some characteristics known from the circular perturbing body are studied: circular, elliptic equatorial, and frozen orbits. Different initial eccentricities for the perturbed body are considered, since the effect of this variable is one of the goals of the present study. the results show the impact of this parameter as well as the differences between both models compared to the full elliptic restricted three-body problem. Regions below, near, and above the critical angle of the third-body perturbation are considered, as well as different altitudes for the orbit of the spacecraft.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilCNPq: 150195/2012-5CNPq: 304700/2009-6FAPESP: 2011/09310-7FAPESP: 2011/08171-3Web of Scienc

Superscars in the LiNC=LiCN isomerization reaction

We demonstrate the existence of superscarring in the LiNC=LiCN isomerization reaction described by a realistic potential interaction in the range of readily attainable experimental energies. This phenomenon arises as the effect of two periodic orbits appearing "out of the blue"in a saddle--node bifurcation taking place in the dynamics of the system. Potential practical consequences of this superlocalization in the corresponding wave functions are also considered.Comment: 6 pages, 5 figures. to appear in EP

The renal and hepatic distribution of Bence Jones proteins depends on glycosylation: A scintigraphic study in rats

The aim of the present study was to evaluate renal and liver distribution of two monoclonal immunoglobulin light chains. the chains were purified individually from the urine of patients with multiple myeloma and characterized as lambda light chains with a molecular mass of 28 kDa. They were named BJg (high amount of galactose residues exposed) and BJs (sialic acid residues exposed) on the basis of carbohydrate content. A scintigraphic study was performed on male Wistar rats weighing 250 g for 60 min after iv administration of 1 mg of each protein (7.4 MBq), as the intact proteins and also after carbohydrate oxidation. Images were obtained with a Siemens gamma camera with a high-resolution collimator and processed with a MicroDelta system. Hepatic and renal distribution were established and are reported as percent of injected dose. Liver uptake of BJg was significantly higher than liver uptake of BJs (94.3 vs 81.4%) (P<0.05). This contributed to its greater removal from the intravascular compartment, and consequently lower kidney accumulation of BJg in comparison to BJs (5.7 vs 18.6%) (P<0.05). After carbohydrate oxidation, there was a decrease in hepatic accumulation of both proteins and consequently a higher renal overload. the tissue distribution of periodate-treated BJg was similar to that of native BJs: 82.7 vs 81.4% in the liver and 17.3 vs 18.6% in the kidneys. These observations indicate the important role of sugar residues of Bence Jones proteins for their recognition by specific membrane receptors, which leads to differential tissue accumulation and possible toxicity.UNIV São Paulo,FAC MED,LAB FISIOPATOL RENAL,BR-01246903 São Paulo,SP,BRAZILUNIV São Paulo,CTR MED NUCL,BR-05403010 São Paulo,SP,BRAZILUNIV São Paulo,HOSP CLIN,SERV RADISISOTOPOS,BR-05403000 São Paulo,SP,BRAZILUniversidade Federal de São Paulo,MOL BIOL LAB,BR-04024900 São Paulo,SP,BRAZILUniversidade Federal de São Paulo,MOL BIOL LAB,BR-04024900 São Paulo,SP,BRAZILWeb of Scienc

Protein extract and activity antioxidant of corn (Zea mays) and sorghum (Sorghum bicolor L. Moench) grains

Brazil is a major producer of grains, such as sorgh um and corn, which are used for export. Sorghum and corn grains have in its composition 9.5% and 9. 8 protein, respectively. Proteins are the most abundant and most diverse functions in living syste ms molecules. Currently, food proteins are increasingly recognized as a source of beneficial b ioactive peptides, and they are physiologically released during digestion. The aim of the work was to evaluate the protein extraction (four methods) and antioxidant activity of sorghum and corn grains . The proximal composition of grains was evaluated in relation to moisture, protein, lipids and ash contents, furthermore were quantified proteins concentration and antioxidant activity by FRAP method in the four extracts. The corn and sorghum grains were ground, homogenized (60 mesh) a nd stored at 5°C until analysis. The protein extraction utilized were: 1) dichloromethane/methan ol; 2) NH 4 HCO 3 (5mM, pH 8.0)/heat treatment; 3) water/ethanol/heat treatment; and 4) alkaline ex traction and precipitation. The corn and sorghum presented, protein 6.62% and 9.87%, lipids 4.45% an d 4.32%, moisture 8.87% and 8.23%, ash 0.96% and 1.15%, carbohydrates 79.01% and 76.41%, t otalizing a caloric value of 382.9 and 384.1 Kcal g -1 , respectively. The 2 and 3 methods in corn grain p resented highest protein content 133.16 and 142.24 μ g g -1 , respectively. In sorghum grain, methods 1, 2 and 3 presented protein content between 173.59 – 223.63 μg g -1 . The antioxidant activity of protein extracts was between 0.90 – 9.73μM of ferrous sulphate for corn and between 4.4 1 – 15.04μ M of ferrous sulphate for sorghum. The best results in the extraction using the method 3 for both grains could be due to the structure of proteins (zein and kafirins) which are soluble in a lcoholic solutions and insoluble in water. In conclusion, method 3 - water/ethanol/heat treatment (corn: 142.24 μg g -1 and sorghum: 223.63 μg g - 1 ) and method 3 (corn: 9.73 μM and sorghum: 15.04 μ M ) showed the best results for extracting protein and antioxidant activity, respectively. The protein extracts obtainedhave great potential as natural antioxidant

Protein extraction of the sunflower grains and bran

[Excerpt] Sunflower grains have a high protein content (24%) with high quality amino acid profile and are used to extraction of vegetable oil. The sunflower brain is produced during the processing of vegetal oil. The sunflower grains and by-product (bran) can be used with raw materials for obtaining peptides with bioactivity for protein hydrolysis after extraction, since they have great amount of essential amino acids, typically nonpolar, soluble and insoluble alcoholic solutions in water. The aim of this work was to evaluate protein extraction (three methods) of sunflower grains and bran. (...

Optimal transfers from Moon to L2L_2 halo orbit of the Earth-Moon system

In this paper, we seek optimal solutions for a transfer from a parking orbit around the Moon to a halo orbit around $L_2$ of the Earth-Moon system, by applying a single maneuver and exploiting the stable invariant manifold of the hyperbolic parking solution at arrival. For that, we propose an optimization problem considering as variables both the orbital characteristics of a parking solution around the Moon, (namely, its Keplerian elements) and the characteristics of a transfer trajectory guided by the stable manifold of the arrival Halo orbit. The problem is solved by a nonlinear programming method (NLP), aiming to minimize the cost of $\Delta V$ to perform a single maneuver transfer, within the framework of the Earth-Moon system of the circular restricted three-body problem. Results with low $\Delta V$ and suitable time of flight show the feasibility of this kind of transfer for a Cubesat