549 research outputs found

    Conservation Laws in Cellular Automata

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    If X is a discrete abelian group and B a finite set, then a cellular automaton (CA) is a continuous map F:B^X-->B^X that commutes with all X-shifts. If g is a real-valued function on B, then, for any b in B^X, we define G(b) to be the sum over all x in X of g(b_x) (if finite). We say g is `conserved' by F if G is constant under the action of F. We characterize such `conservation laws' in several ways, deriving both theoretical consequences and practical tests, and provide a method for constructing all one-dimensional CA exhibiting a given conservation law.Comment: 19 pages, LaTeX 2E with one (1) Encapsulated PostScript figure. To appear in Nonlinearity. (v2) minor changes/corrections; new references added to bibliograph

    Fetal development and blood hematological-biochemical parameters in Campeiro and Pantaneiro foals.

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    Made available in DSpace on 2019-01-02T23:37:38Z (GMT). No. of bitstreams: 1 2018Vieiraetal..pdf: 293128 bytes, checksum: 55472a23573b40b9efd496c73b492ee6 (MD5) Previous issue date: 2019-01-02bitstream/item/189575/1/2018-Vieira-et-al.-.pd

    Fermi LAT Gamma-ray Detections of Classical Novae V1369 Centauri 2013 and V5668 Sagittarii 2015

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    We report the Fermi Large Area Telescope (LAT) detections of high-energy (>100 MeV) gamma-ray emission from two recent optically bright classical novae, V1369 Centauri 2013 and V5668 Sagittarii 2015. At early times, Fermi target-of-opportunity observations prompted by their optical discoveries provided enhanced LAT exposure that enabled the detections of gamma-ray onsets beginning ~2 days after their first optical peaks. Significant gamma-ray emission was found extending to 39-55 days after their initial LAT detections, with systematically fainter and longer duration emission compared to previous gamma-ray detected classical novae. These novae were distinguished by multiple bright optical peaks that encompassed the timespans of the observed gamma rays. The gamma-ray light curves and spectra of the two novae are presented along with representative hadronic and leptonic models, and comparisons to other novae detected by the LAT are discussed.Comment: 13 pages, 6 figures, 4 tables, ApJ accepte

    Ultrasound evaluation of ovarian dynamics in Indubrasil cows submitted to two nutritional managements.

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    The objective of this study was to compare ovarian dynamics of Indubrasil cows submitted to grazing or confinement regimes. Follicular growth was monitored daily starting at estrus during two consecutive estrous cycles in seven adult non-lactating Indubrasil cows with body score 4 (classification 1 to 5), in 2x7 experiment. The first evaluation was in the grazing regime, when animals were kept in pastures of Brachiaria brizantha cv Marandu intercropped with Leucaena leococephala, with water and mineral salt ad libitum. The second evaluation was performed during the following estrous cycle when animals were submitted to the confinement regime, and fed with corn silage, proteinated mineral salt and water ad libitum. An ultrasound HS 1500 (HondaŸ, Japan) equipped with a linear 7.5 MHZ probe was used to assess follicle and luteal dynamics. Data were recorded according to the day of the cycle and are presented as means ± standard deviation. Means were compared by T Tests and differences considered significant when P<0.05. The duration of the first estrous was 20±1.6 and 21±1.22 days for grazing and confined animals, respectively. The number of follicular waves was 2±0.49 and 3±0.40 and their duration was 9±1.99 and 9±1.65 days, for grazing and confined animals, respectively. The maximum diameter of the ovulatory follicle was larger in confined (15±0.51mm; p <0.05) than grazing animals (13±0.87mm). For subordinate follicles, the maximum diameter was 9±1.13mm and 9±0.82mm for grazing and confined animals, respectively. The dominant follicle persisted for 7±1.41 and 6±0.82 days in grazing and confined animals, respectively. Finally, the persistence of the corpus luteum was 14±1.59 and 15±1.06 days for grazing and confined animals, respectively. These data suggest that diet influences growth rate and size of the ovulatory follicle in Indubrasil cows. We speculate that greater dry matter intake in the confinement regime may have promoted an increase in the metabolism of steroid hormones, influencing dominant follicle growth. This abstract describes for the first time follicle dynamics in Indubrasil cows, which was found to be very similar to other Bos indicus breeds

    Probabilistic cellular automata with conserved quantities

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    We demonstrate that the concept of a conservation law can be naturally extended from deterministic to probabilistic cellular automata (PCA) rules. The local function for conservative PCA must satisfy conditions analogous to conservation conditions for deterministic cellular automata. Conservation condition for PCA can also be written in the form of a current conservation law. For deterministic nearest-neighbour CA the current can be computed exactly. Local structure approximation can partially predict the equilibrium current for non-deterministic cases. For linear segments of the fundamental diagram it actually produces exact results.Comment: 17 pages, 2 figure

    Large scale anisotropies on halo infall

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    We perform a statistical analysis of the peculiar velocity field around dark matter haloes in numerical simulations. We examine different properties of the infall of material onto haloes and its relation to central halo shapes and the shape of the large scale surrounding regions (LSSR). We find that the amplitude of the infall velocity field along the halo shape minor axis is larger than that along the major axis. This is consistent for general triaxial haloes, and for both prolate and oblate systems. We also report a strong anisotropy of the velocity field along the principal axes of the LSSR. The infall velocity field around dark matter haloes reaches a maximum value along the direction of the minor axis of the LSSR, whereas along the direction of its major axis, it exhibits the smallest velocities. We also analyse the dependence of the matter velocity field on the local environment. The amplitude of the infall velocity at high local density regions is larger than at low local density regions. The velocity field tends to be more laminar along the direction towards the minor axis of the LSSR, where the mean ratio between flow velocity and velocity dispersion is of order unity and nearly constant up to scales of 15 Mpc/h. We also detect anisotropies in the outflowing component of the velocity field, showing a maximum amplitude along the surrounding LSSR major axis.Comment: 12 pages, 9 figures, accepted for publication in Monthly Notices of the Royal Astronomical Societ
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