Statistical relationships of cnidocyst sizes in the sea anemone Oulactis muscosa (Actiniaria: Actiniidae)

This study analysis the multivariate statistical relationships among cnidocyst types and tissues in terms of cnidocyst capsule size in the sea anemone O. muscosa. In a total of 12 individuals we measured the length of 30 unfired capsules of each cnida type, taken randomly from each of the following tissues: tentacles, acrorhagi, column, actinopharynx and mesenterial filaments. In these tissues, we found spirocysts, basitrichs, microbasic b-mastigophores, microbasic p-mastigophores and holotrichs. Thus, a total of 5400 measurements were made. Looking for a common pattern of variation, a principal components analysis (PCA) was performed on the data matrix, among cnidocyst types for each tissue and between tissues for each cnidocyst type. The results showed that the lengths of most cnidocysts, whether from the same or different tissues, are not statistically related to each other, suggesting that different forces (cnidogenesis, replacement dynamics, etc.), could affect in various forms the development and therefore the length of each cnida, depending on the type or tissue of origin.Fil: Acuña, Fabian Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Determinants of Chilean youth voter registration: Evidence for the Bio Bio region

Youth voter registration is a worldwide phenomenon that exhibits a marked decline over the last two decades. On this basis, this article presents evidence regarding those factors that determine the voter registration of Chilean youth, in particular, the inhabitants of Bio Bio region. The methodology uses a linear model, proposed by Silberman and Durden (1975), which considers a relationship between voter registration and several social/economic variables. The model is estimated using a dynamic panel for the Bio Bio region, which includes its 54 communes and 10 planning territories for the years 2003 and 2009. The results indicate that, at commune level, the main determinants of youth voter registration are citizen participation and poverty rates, while ethnic aspects are also affecting female voter registration, and only citizen participation rate has some influence over male voter registration. Finally, at territory level, the results show that citizen participation rate is a cross determinant of youth voter registration in the Bio Bio region.citizen participation; panel data; unobserved effects model; voter registration

Critical phenomena of the Majority voter model in a three dimensional cubic lattice

In this work we investigate the critical behavior of the three dimensional simple-cubic Majority voter model. Using numerical simulations and a combination of two different cumulants we evaluated the critical point with a higher accuracy than the previous numerical result found by Yang et al. [J.- S. Yang, I.-M. Kim and W. Kwak, Phys. Rev. E 77, 051122 (2008)]. Using standard Finite Size Scaling theory and scaling corrections we find that the critical exponents {\nu}, {\gamma} and {\beta} are the same as those of the three dimensional Ising model.Comment: 5 pages, 5 figures. Accepted in PR

Money and Real Fluctuations: Calibrating a Cash in Advance Model for the Chilean Economy

In this paper we assess the ability of a cash-in-advance model to replicate the behavior of the macroeconomic variables of the Chilean economy for quarterly data spanning between Q1:1986 and Q1:2000. The monetary models that we studied are able to replicate the phase shift and correlation with GDP of many macroeconomics variables such as consumption, price level and productivity. However, there are some other variables in which the model fails; namely money and capital stock. Introducing an "erratic" monetary growth rate improves the ability of the model to replicate the behavior of consumption. A sensitivity analysis shows that the main determinant of output volatility is the standard deviation of technology shock. Other deep parameters do not have an important quantitative effect on the cyclical behaviour of the macroeconomic variables.monetary fluctuations; real business cycles; general equilibrium

New record for the distribution of the colonial hydroid Cordylophora caspia (Pallas, 1771) (Cnidaria: Hydrozoa) in Argentina

Cordylophora caspia is a colonial, athecate hydroid inhabiting both in freshwater and brackish habitats. Its global distribution is in part due to its ability to tolerate a wide range of salinity. It is considered an invasive species and its control is widely studied because of the industrial and ecological problems it causes in many environments. We report for the first time the occurrence of this hydrozoan in Nahuel Rucá Lake (Buenos Aires province, Argentina) with some notes on its internal and external morphology.Fil: Deserti, Maria Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Escalante, Alicia Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Acuña, Fabian Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin