327 research outputs found
Sociophysics Simulations I: Language Competition
Using a bit-string model similar to biological simulations, the competition
between different languages is simulated both without and with spatial
structure. We compare our agent-based work with differential equations and the
competing bit-string model of Kosmidis et al.Comment: 8th Granada Seminar (sociophysics); for AIP Conf. Proc. (8 pages
incl. figs
Monte Carlo simulation of the rise and the fall of languages
Similar to biological evolution and speciation we define a language through a
string of 8 or 16 bits. The parent gives its language to its children, apart
from a random mutation from zero to one or from one to zero; initially all bits
are zero. The Verhulst deaths are taken as proportional to the total number of
people, while in addition languages spoken by many people are preferred over
small languages. For a fixed population size, a sharp phase transition is
observed: For low mutation rates, one language contains nearly all people; for
high mutation rates, no language dominates and the size distribution of
languages is roughly log-normal as for present human languages. A simple
scaling law is valid.Comment: 8 pages including all figs., for IJMPC. New version with new results
at en
Identifizierung von Haplotypen bei Pityogenes chalcographus (Col., Scolytidae) durch SSCP
Pityogenes chalcographus is a widely distributed spruce pest in Eurasia (KNIZEK et al. 2005). In 70ies, E. Führer studied the intraspecific variation of this spruce bark beetle and detected race differentiation among European populations based on crossing experiments (FÜHRER 1977), morphological characters FÜHRER 1978) and allozyme electrophoresis (RITZENGRUBER 1990). In order to verify the hypothesis differentiation, we analysed diverse European P. chalcographus populations using the Cytochrome Oxidase gene (COI) of the mitochondrial DNA. The complete COI gene of 96 individuals was sequenced. In facilitate the screening of the European populations, we applied a PCR-SSCP method. This polyacrylamide electrophoresis technique offers a sensitive but inexpensive, rapid and convenient method for detecting polymorphisms, reducing the amount of samples that require sequencing (SUNNUCKS et al. 2000).Der Kupferstecher Pityogenes chalcographus (Coleoptera, Scolytidae) gehört zu den am weitesten verbreiteten Borkenkäfern Europas. Käferpopulationen aus verschiedenen Gebieten Europas zeigten eine hohe Divergenz hinsichtlich der Nukleotidzusammensetzung des mitochondrialen Cytochrom Oxidase I Gens. Die Unterschiede betragen bis zu 2,26% zwischen einzelnen Herkünften. Die phylogenetische Auswertung der Sequenzen des kompletten Gens (1503bp) ergab einen 6-astigen Baum mit insgesamt 34 Haplotypen. Ausgehend von dieser Struktur wurden Primerpaare entworfen, um jeweils etwa 250 bp lange mutationsreiche Abschnitte des COI Gens zu amplifizieren. Die PCR Produkte wurden mittels Single Strand Conformation Polymorphism (SSCP) untersucht. Zwischen den einzelnen Haplotypen konnten zahlreiche Polymorphismen erkannt werden. Diese eignen sich als schnelles Werkzeug zum screening einzelner Individuen und verringern signifikant die Notwendigkeit klassischer Sequenzierreaktionen
Competition of languages in the presence of a barrier
Using the Schulze model for Monte Carlo simulations of language competition,
we include a barrier between the top half and the bottom half of the lattice.
We check under which conditions two different languages evolve as dominating in
the two halves.Comment: 6 pages including 3 figure
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