ESR studies of the slow tumbling of vanadyl spin probes in nematic liquid crystals

ESR line shapes that are appropriate for slowly tumbling vanadyl spin probes in viscous nematic liquid crystals were calculated by the stochastic Liouville method. Because of the symmetry possessed by vanadyl, the analysis and interpretation of these line shapes was simplified considerably. Spectral line shapes agreed well with experimental spectra of VOAcAc in the nematic liquid crystal Phase V and BEPC. Deviations from Brownian rotational diffusion were noted. A slowly fluctuating torque analysis yielded good agreement with the experimental spectra

Self-consistent physical parameters for MC clusters from CMD modelling: application to SMC clusters observed with the SOAR telescope

The Magellanic Clouds (MCs) present a rich system of stellar clusters that can be used to probe the dynamical and chemical evolution of these neighboring and interacting irregular galaxies. In particular, these stellar clusters (SCs) present combinations of age and metallicity that are not found for this class of objects in the Milky Way, being therefore very useful templates to test and to calibrate integrated light simple stellar population (SSP) models applied to unresolved distance galaxies. On its turn, the age and metallicity for a cluster can be determined spatially resolving its stars, by means of analysis of its colour-magnitude diagrams (CMDs). In this work we present our method to determine self-consistent physical parameters (age, metallicity, distance modulus and reddening) for a stellar cluster, from CMDs modelling of relatively unstudied SCs in the Small Magellanic Cloud (SMC) imaged in the BVI filters with the 4.1 m SOAR telescope. Our preliminary results confirm our expectations that come from a previous integrated spectra and colour analysis: at least one of them (Lindsay 2) is an intermediate-age stellar cluster with ~ 2.6 Gyr and [Fe/H] ~ -1.3, being therefore a new interesting witness regarding the reactivation of the star formation in the MCs in the last 4 Gyr.Comment: 4 pages, 2 figures. To be published in the proceedings of IAUS256: The Magellanic System: Stars, Gas, and Galaxie

Contour methods for long-range Ising models: weakening nearest-neighbor interactions and adding decaying fields

We consider ferromagnetic long-range Ising models which display phase transitions. They are long-range one-dimensional Ising ferromagnets, in which the interaction is given by $J_{x,y} = J(|x-y|)\equiv \frac{1}{|x-y|^{2-\alpha}}$ with $\alpha \in [0, 1)$, in particular, $J(1)=1$. For this class of models one way in which one can prove the phase transition is via a kind of Peierls contour argument, using the adaptation of the Fr\"ohlich-Spencer contours for $\alpha \neq 0$, proposed by Cassandro, Ferrari, Merola and Presutti. As proved by Fr\"ohlich and Spencer for $\alpha=0$ and conjectured by Cassandro et al for the region they could treat, $\alpha \in (0,\alpha_{+})$ for $\alpha_+=\log(3)/\log(2)-1$, although in the literature dealing with contour methods for these models it is generally assumed that $J(1)\gg1$, we can show that this condition can be removed in the contour analysis. In addition, combining our theorem with a recent result of Littin and Picco we prove the persistence of the contour proof of the phase transition for any $\alpha \in [0,1)$. Moreover, we show that when we add a magnetic field decaying to zero, given by $h_x= h_*\cdot(1+|x|)^{-\gamma}$ and $\gamma >\max\{1-\alpha, 1-\alpha^* \}$ where $\alpha^*\approx 0.2714$, the transition still persists.Comment: 13 page

Quality of high dimensional numerical “Space filling designs” for the sensitivity analysis of interference optical filters

AbstractIn the field of computer experiments, when the relations between the outputs and the inputs of the computer code are complex, the Space Filling Designs (SFD) are used to study the outputs all over the domain or to build metamodels. We introduce here the results of SFD quality obtained in high dimensional case by the methodology of Minimum Spanning Tree (MST). Then, different SFD are used for the sensitivity analysis of interference optical filters. The intrinsic quality of SFD is assessed by MST criterion and is proved to be in accordance with the results of the optical filter sensitivity analysis. This study can be considered as a first step to connect intrinsic quality and extrinsic quality of SFD designs

Biology and Conservation of the Freshwater Turtles and Tortoises of Peru

Little information has been published on Peruvian chelonians. Here we have compiled the available literature pertaining to Peruvian freshwater turtles and tortoises on four topics: Human consumption and ethnobiology, habitat use, status and abundance, and reproduction. In addition, we provide a map of the regions of Peru showing the number of research records and the number of species that occur in each region. Reproduction was the topic most frequently studied, although investigations were concentrated on only three species (Podocnemis unifilis, P. expansa, P. sextuberculata). The regions where the most studies were implemented are the Departamentos de Loreto and Madre de Dios, with studies tending to be concentrated in the vicinity of  Iquitos, the Pacaya-Samiria National Reserve, and Manu National Park and its buffer zone. In general, regions in which more research effort was evident reported more turtle species, which suggests that the least-studied states could have more species, as they share the same types of habitats as the more intensely investigated regions. We identified major gaps in information and suggest future research in the following poorly studied Peruvian regions: Departaments of Junín, San Martín, Tumbes, Huanuco, Amazonas, Cusco, Ayacucho, Puno, Huancavelica, and Cajamarca. The status, distribution, and abundance of Peruvian populations of Podocnemis expansa, P. unifilis, Chelonoidis carbonaria, Peltocephalus dumerilianus, and Mesoclemmys heliostemma are in particular need  of study. Conservation priorities are also discussed

Tabulation of PVI Transcendents and Parametrization Formulas (August 17, 2011)

The critical and asymptotic behaviors of solutions of the sixth Painlev\'e equation PVI, obtained in the framework of the monodromy preserving deformation method, and their explicit parametrization in terms of monodromy data, are tabulated.Comment: 30 pages, 1 figure; Nonlinearity 201

Kitchen-Sink Enlightenment: A Review of “Grace for Amateurs”

Excerpt: Here’s an honest admission: Several times while reading Lily Burana’s new book Grace for Amateurs: Field Notes on a Journey Back to Faith, I consulted the copyright page, confirming again that Grace for Amateurs was really published by Thomas Nelson, the notoriously evangelical (and, in my mind, notoriously traditional) press. After all, it wasn’t that long ago that Thomas Nelson asked another writer to remove the word “vagina” from her book, well aware that Christian readers would balk at language so closely associated with women and S-E-X. Would this same publisher be willing to support a memoir as edgy and progressive as Burana’s