Dynamical properties for an ensemble of classical particles moving in a driven potential well with different time perturbation

We consider dynamical properties for an ensemble of classical particles confined to an infinite box of potential and containing a time-dependent potential well described by different nonlinear functions. For smooth functions, the phase space contains chaotic trajectories, periodic islands and invariant spanning curves preventing the unlimited particle diffusion along the energy axis. Average properties of the chaotic sea are characterised as a function of the control parameters and exponents describing their behaviour show no dependence on the perturbation functions. Given invariant spanning curves are present in the phase space, a sticky region was observed and show to modify locally the diffusion of the particles. © 2013 Elsevier B.V.

A theoretical characterization of scaling properties in a bouncing ball system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Scaling invariance for the escape of particles from a periodically corrugated waveguide

The escape dynamics of a classical light ray inside a corrugated waveguide is characterised by the use of scaling arguments. The model is described via a two-dimensional nonlinear and area preserving mapping. The phase space of the mapping contains a set of periodic islands surrounded by a large chaotic sea that is confined by a set of invariant tori. When a hole is introduced in the chaotic sea, letting the ray escape, the histogram of frequency of the number of escaping particles exhibits rapid growth, reaching a maximum value at n(p) and later decaying asymptotically to zero. The behaviour of the histogram of escape frequency is characterised using scaling arguments. The scaling formalism is widely applicable to critical phenomena and useful in characterisation of phase transitions, including transitions from limited to unlimited energy growth in two-dimensional time varying billiard problems. (C) 2011 Elsevier B.V. All rights reserved.

Mineral chemistry and structural relationships of inclusions in diamond samples

Diamant ist das härteste Mineral – und dazu ein Edelstein -, das unter höchstem Druck und hohen Temperaturen in tiefen kontinentalen Regionen der Erde kristallisiert. Die Mineraleinschlüsse in Diamanten werden durch die physikalische Stabilität und chemische Beständigkeit der umgebenden – eigentlich metastabilen -Diamant-Phase geschützt. Aufgrund der koexistierenden Phasenkombination ermöglichen sie, die Mineral-Entwicklung zu studieren, während deren der Einschlüssen und die Diamanten kristallisierten. rnDie Phasenkombinationen von Diamant und Chrom-Pyrop, Chrom-Diopsid, Chromit, Olivin, Graphit und Enstatit nebeneinander (teilweise in Berührungsexistenz) mit Chrom-Pyrop Einschlüssen wurden von neunundzwanzig Diamant-Proben von sechs Standorten in Südafrika (Premier, Koffiefontein, De Beers Pool, Finsch, Venetia und Koingnaas Minen) und Udachnaya (Sibirien/Russland) identifiziert und charakterisiert. Die Mineraleinschlüsse weisen z.T. kubo-oktaedrische Form auf, die unabhängig von ihren eigenen Kristallsystemen ausgebildet werden können. Das bedeutet, dass sie syngenetische Einschlüsse sind, die durch die sehr hohe Formenergie des umgebenden Diamanten morphologisch unter Zwang stehen. Aus zweidiemnsionalen Messungen der ersten Ordnung von charakteristischen Raman-Banden lassen sich relative Restdrucke in Diamanten zwischen Diamant und Einschlussmineral gewinnen; sie haben charakteristische Werte von ca. 0,4 bis 0,9 GPa um Chrom-Pyrop-Einschlüsse, 0,6 bis 2,0 GPa um Chrom-Diopsid-Einschlüsse, 0,3 bis 1,2 GPa um Olivin-Einschlüsse, 0,2 bis 1,0 GPa um Chromit-Einschlüsse, beziehungsweise 0,5 GPa um Graphit Einschlüsse.rnDie kristallstrukturellen Beziehung von Diamanten und ihren monomineralischen Einschlüssen wurden mit Hilfe der Quantifizierung der Winkelkorrelationen zwischen der [111] Richtung von Diamanten und spezifisch ausgewählten Richtungen ihrer mineralischen Einschlüsse untersucht. Die Winkelkorrelationen zwischen Diamant [111] und Chrom-Pyrop [111] oder Chromit [111] zeigen die kleinsten Verzerrungen von 2,2 bis zu 3,4. Die Chrom-Diopsid- und Olivin-Einschlüsse zeigen die Missorientierungswerte mit Diamant [111] bis zu 10,2 und 12,9 von Chrom-Diopsid [010] beziehungsweise Olivin [100].rnDie chemische Zusammensetzung von neun herausgearbeiteten (orientiertes Anschleifen) Einschlüssen (drei Chrom-Pyrop-Einschlüsse von Koffiefontein-, Finsch- und Venetia-Mine (zwei von drei koexistieren nebeneinander mit Enstatit), ein Chromit von Udachnaya (Sibirien/Russland), drei Chrom-Diopside von Koffiefontein, Koingnaas und Udachnaya (Sibirien/Russland) und zwei Olivin Einschlüsse von De Beers Pool und Koingnaas) wurden mit Hilfe EPMA und LA-ICP-MS analysiert. Auf der Grundlage der chemischen Zusammensetzung können die Mineraleinschlüsse in Diamanten in dieser Arbeit der peridotitischen Suite zugeordnet werden.rnDie Geothermobarometrie-Untersuchungen waren aufgrund der berührenden Koexistenz von Chrom-Pyrop- und Enstatit in einzelnen Diamanten möglich. Durchschnittliche Temperaturen und Drücke der Bildung sind mit ca. 1087 (± 15) C, 5,2 (± 0,1) GPa für Diamant DHK6.2 von der Koffiefontein Mine beziehungsweise ca. 1041 (± 5) C, 5,0 (± 0,1) GPa für Diamant DHF10.2 von der Finsch Mine zu interpretieren.rn

Regulation of v-Mos kinase activity by phosphorylation

In this thesis, I investigated the effect of cylic AMP-dependent protein kinase (PKA) on v-Mos kinase activity. Increase in PKA activity in vivo brought about either by forskolin treatment or by overexpression of the PKA catalytic subunit resulted in a significant inhibition of v-Mos kinase activity. The purified PKA catalytic subunit was able to phosphorylate recombinant p37$\rm\sp{v-mos}$ in vitro, suggesting that the mechanism of in vivo inhibition of v-Mos kinase involves direct phosphorylation by PKA. Ser-263 was identified as a residue that is normally phosphorylated at a very low level but whose phosphorylation is dramatically increased upon forskolin treatment. Consistent with the inhibitory role of Ser-263 phosphorylation, the Ala-263 mutant of v-Mos was not inhibited by forskolin treatment. Based on our results, we propose that the known inhibitory role of PKA in the initiation of oocyte maturation could be explained at least in part by its inhibition of Mos kinase.^ Combining tryptic phosphopeptide two-dimensional mapping analysis and in vitro mutagenesis studies, I identified Ser-56 as the major in vivo phosphorylation site on v-Mos. I studied the interrelationship between Ser-34 and Ser-56 phosphorylation in regulating v-Mos function. After site-directed mutagenesis to substitute serine residues with alanine or glutamic acid in different combinations to mimick unphosphorylated and phosphorylated serines respectively, various v-Mos mutants were expressed in COS-1 cells. As expected, Ala-34 mutant of v-Mos had very low (less 5% of wild type) kinase activity. The Ala-56 mutant had kinase activity 50% that of wild type. Surprisingly, the Ala-34 Ala-56 double mutant and the Ala-56 mutant exhibited identical kinase activity. On the other hand, Ala-34 Glu-56 double mutant had reduced kinase activity comparable to Ala-34 mutant. These results suggest that the phosphorylation at Ser-56 may serve to inhibit the activation of newly synthesized Mos protein. As predicted from Xenopus c-Mos studies, Glu-34 mutant of v-Mos was highly active (125% that of wild type). Interestingly, consistant with the model involving an inhibitory role of Ser-56 phosphorylation, the Glu-34 Glu-56 double mutant was totally inactive as a kinase. Moreover in my experiments, there was a perfect correlation between the level of v-Mos kinase activity of various mutants and their transforming activity. The latter is dependent upon MEK1 phosphorylation/ activation in v-mos transformed cells. Residues corresponding to both v-Mos Ser-34 and Ser-56 are evolutionarily conserved in c-Mos. Therefore, the cytostatic factor function of c-Mos may be regulated in the same manner as v-Mos kinase activity.^ It has been known that v-mos transforms cells by affecting G1 phase progression of the cell cycle. Here I showed that mos induces cyclin D1 expression in mos transformed NIH 3T3 cells and NRK 6m2 cells, and this induced level was found to be unaffected by serum starvation. Consequently, cyclin D1-Cdk4 and cyclin E-Cdk2 activities increase, and retinoblastoma protein is hyperphosphorylated. Based on studies from several laboratories, these findings suggest that increased amount of cyclin D1-Cdk4 complexes ties up the limited amount of cyclin E-Cdk2 inhibitors (e.g. p27), causing the activation of cyclin E-Cdk2. My results indicate that activation of key cell cycle regulators of G1 phase may be important for cellular transformation by mos. (Abstract shortened by UMI.) ^

Mapping the royal road and other hierarchical functions

In this paper we present a technique for visualising hierarchical and symmetric, multimodal fitness functions that have been investigated in the evolutionary computation literature. The focus of this technique is on landscapes in moderate-dimensional, binary spaces (i.e., fitness functions defined over {0, 1}(n), for n less than or equal to 16). The visualisation approach involves an unfolding of the hyperspace into a two-dimensional graph, whose layout represents the topology of the space using a recursive relationship, and whose shading defines the shape of the cost surface defined on the space. Using this technique we present case-study explorations of three fitness functions: royal road, hierarchical-if-and-only-if (H-IFF), and hierarchically decomposable functions (HDF). The visualisation approach provides an insight into the properties of these functions, particularly with respect to the size and shape of the basins of attraction around each of the local optima.

Separation and Mapping of Chromosomes of Parasitic Protozoa

Many protozoan parasites represent an important group of human pathogens. Pulsed Field Gradient Gel Electrophoresis (PFGE) analysis has been an important tool for fundamental genetic studies of parasites like Trypanosoma, Leishmania, Giardia or the human malaria parasite Plasmodium falciparum. We present PFGE conditions allowing a high resolution separation of chromosomes ranging from 500 to 4000 kb within a two day electrophoresis run. In addition, we present conditions for separating large chromosomes (2000-6000 kb) within 36 hr. We demontrate that the application of two dimentional PFGE (2D-PFGE) technique to parasite karyotypes is a very useful method for the analysis of dispersed gene families and comparative studies of the intrachomosomal genome organization

Dynamic perceptual mapping

Perceptual maps have been used for decades by market researchers to illuminatethem about the similarity between brands in terms of a set of attributes, to position consumersrelative to brands in terms of their preferences, or to study how demographic and psychometricvariables relate to consumer choice. Invariably these maps are two-dimensional and static. Aswe enter the era of electronic publishing, the possibilities for dynamic graphics are opening up.We demonstrate the usefulness of introducing motion into perceptual maps through fourexamples. The first example shows how a perceptual map can be viewed in three dimensions,and the second one moves between two analyses of the data that were collected according todifferent protocols. In a third example we move from the best view of the data at the individuallevel to one which focuses on between-group differences in aggregated data. A final exampleconsiders the case when several demographic variables or market segments are available foreach respondent, showing an animation with increasingly detailed demographic comparisons.These examples of dynamic maps use several data sets from marketing and social scienceresearch.

Interest rates mapping

The present study deals with the analysis and mapping of Swiss franc interest rates. Interest rates depend on time and maturity, defining term structure of the interest rate curves (IRC). In the present study IRC are considered in a two-dimensional feature space - time and maturity. Exploratory data analysis includes a variety of tools widely used in econophysics and geostatistics. Geostatistical models and machine learning algorithms (multilayer perceptron and Support Vector Machines) were applied to produce interest rate maps. IR maps can be used for the visualisation and pattern perception purposes, to develop and to explore economical hypotheses, to produce dynamic asset-liability simulations and for financial risk assessments. The feasibility of an application of interest rates mapping approach for the IRC forecasting is considered as well. (C) 2008 Elsevier B.V. All rights reserved.

Single acquisition electrical property mapping based on relative coil sensitivities: A proof-of-concept demonstration.

PURPOSE: All methods presented to date to map both conductivity and permittivity rely on multiple acquisitions to compute quantitatively the magnitude of radiofrequency transmit fields, B1+. In this work, we propose a method to compute both conductivity and permittivity based solely on relative receive coil sensitivities ( B1-) that can be obtained in one single measurement without the need to neither explicitly perform transmit/receive phase separation nor make assumptions regarding those phases. THEORY AND METHODS: To demonstrate the validity and the noise sensitivity of our method we used electromagnetic finite differences simulations of a 16-channel transceiver array. To experimentally validate our methodology at 7 Tesla, multi compartment phantom data was acquired using a standard 32-channel receive coil system and two-dimensional (2D) and 3D gradient echo acquisition. The reconstructed electric properties were correlated to those measured using dielectric probes. RESULTS: The method was demonstrated both in simulations and in phantom data with correlations to both the modeled and bench measurements being close to identity. The noise properties were modeled and understood. CONCLUSION: The proposed methodology allows to quantitatively determine the electrical properties of a sample using any MR contrast, with the only constraint being the need to have 4 or more receive coils and high SNR. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.

Prenatal diagnosis of Beckwith-Wiedemann syndrome by two- and three-dimensional ultrasonography

Beckwith-Wiedemann syndrome is a genetic syndrome characterized by macroglossia, omphalocele, fetal gigantism and neonatal hypoglycemia. The authors report a case of Beckwith-Wiedemann syndrome diagnosed in a 32-year-old primigravida in whom two-dimensional ultrasonography revealed the presence of abdominal wall cyst, macroglossia and polycystic kidneys. Three-dimensional ultrasonography in rendering mode was of great importance to confirm the previous two-dimensional ultrasonography findings.

Comparison of Two- and Three-dimensional Ultrasonography in the Evaluation of Lesion Level in Fetuses with Spina Bifida

Purpose To evaluate the precision of both two- and three-dimensional ultrasonography in determining vertebral lesion level (the first open vertebra) in patients with spina bifida. Methods This was a prospective longitudinal study comprising of fetuses with open spina bifida who were treated in the fetal medicine division of the department of obstetrics of Hospital das Clínicas of the Universidade de São Paulo between 2004 and 2013. Vertebral lesion level was established by using both two- and three-dimensional ultrasonography in 50 fetuses (two examiners in each method). The lesion level in the neonatal period was established by radiological assessment of the spine. All pregnancies were followed in our hospital prenatally, and delivery was scheduled to allow immediate postnatal surgical correction. Results Two-dimensional sonography precisely estimated the spina bifida level in 53% of the cases. The estimate error was within one vertebra in 80% of the cases, in up to two vertebrae in 89%, and in up to three vertebrae in 100%, showing a good interobserver agreement. Three-dimensional ultrasonography precisely estimated the lesion level in 50% of the cases. The estimate error was within one vertebra in 82% of the cases, in up to two vertebrae in 90%, and in up to three vertebrae in 100%, also showing good interobserver agreement. Whenever an estimate error was observed, both two- and three-dimensional ultrasonography scans tended to underestimate the true lesion level (55.3% and 62% of the cases, respectively). Conclusions No relevant difference in diagnostic performance was observed between the two- and three-dimensional ultrasonography. The use of three-dimensional ultrasonography showed no additional benefit in diagnosing the lesion level in the fetuses with spina bifida. Errors in both methods showed a tendency to underestimate lesion level.

Mapping fibre orientation in complex-shaped biological systems with micrometre resolution by scanning X-ray microdiffraction

A fully automated procedure to extract and to image local fibre orientation in biological tissues from scanning X-ray diffraction is presented. The preferred chitin fibre orientation in the flow sensing system of crickets is determined with high spatial resolution by applying synchrotron radiation based X-ray microbeam diffraction in conjunction with advanced sample sectioning using a UV micro-laser. The data analysis is based on an automated detection of azimuthal diffraction maxima after 2D convolution filtering (smoothing) of the 2D diffraction patterns. Under the assumption of crystallographic fibre symmetry around the morphological fibre axis, the evaluation method allows mapping the three-dimensional orientation of the fibre axes in space. The resulting two-dimensional maps of the local fibre orientations - together with the complex shape of the flow sensing system - may be useful for a better understanding of the mechanical optimization of such tissues.

Two- and three-dimensional shape fabric analysis by the intercept method in grey levels

The count intercept is a robust method for the numerical analysis of fabrics Launeau and Robin (1996). It counts the number of intersections between a set of parallel scan lines and a mineral phase, which must be identified on a digital image. However, the method is only sensitive to boundaries and therefore supposes the user has some knowledge about their significance. The aim of this paper is to show that a proper grey level detection of boundaries along scan lines is sufficient to calculate the two-dimensional anisotropy of grain or crystal distributions without any particular image processing. Populations of grains and crystals usually display elliptical anisotropies in rocks. When confirmed by the intercept analysis, a combination of a minimum of 3 mean length intercept roses, taken on 3 more or less perpendicular sections, allows the calculation of 3-dimensional ellipsoids and the determination of their standard deviation with direction and intensity in 3 dimensions as well. The feasibility of this quick method is attested by numerous examples on theoretical objects deformed by active and passive deformation, on BSE images of synthetic magma flow, on drawing or direct analysis of thin section pictures of sandstones and on digital images of granites directly taken and measured in the field. (C) 2010 Elsevier B.V. All rights reserved.

Dimensional Compactification and Two-Particle Binding

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)