Length-weight relationships of coral reef fishes from the Alacran Reef, Yucatan, Mexico

Length-weight relationships were computed for 42 species of coral reef fishes from 14 families from the Alacran Reef (Yucatan, Mexico). A total of 1 892 individuals was used for this purpose. The fish species were caught by different fishing techniques such as fishhooks, harpoons, gill and trawl nets. The sampling period was from March 1998 to January 2000

Entropy involved in fidelity of DNA replication

Information has an entropic character which can be analyzed within the Statistical Theory in molecular systems. R. Landauer and C.H. Bennett showed that a logical copy can be carried out in the limit of no dissipation if the computation is performed sufficiently slowly. Structural and recent single-molecule assays have provided dynamic details of polymerase machinery with insight into information processing. We introduce a rigorous characterization of Shannon Information in biomolecular systems and apply it to DNA replication in the limit of no dissipation. Specifically, we devise an equilibrium pathway in DNA replication to determine the entropy generated in copying the information from a DNA template in the absence of friction. Both the initial state, the free nucleotides randomly distributed in certain concentrations, and the final state, a polymerized strand, are mesoscopic equilibrium states for the nucleotide distribution. We use empirical stacking free energies to calculate the probabilities of incorporation of the nucleotides. The copied strand is, to first order of approximation, a state of independent and non-indentically distributed random variables for which the nucleotide that is incorporated by the polymerase at each step is dictated by the template strand, and to second order of approximation, a state of non-uniformly distributed random variables with nearest-neighbor interactions for which the recognition of secondary structure by the polymerase in the resultant double-stranded polymer determines the entropy of the replicated strand. Two incorporation mechanisms arise naturally and their biological meanings are explained. It is known that replication occurs far from equilibrium and therefore the Shannon entropy here derived represents an upper bound for replication to take place. Likewise, this entropy sets a universal lower bound for the copying fidelity in replication.Comment: 25 pages, 5 figure

Lifting properties in operator ranges

Given a bounded positive linear operator A on a Hilbert space H we consider the semi-Hilbertian space (H, _A), where _A =. On the other hand, we consider the operator range R(A^1/2) with its canonical Hilbertian structure, denoted by R(A^1/2). In this paper we explore the relationship between different types of operators on (H, _A) with classical subsets of operators on R(A^1/2), like Hermitian, normal, contractions, projections, partial isometries and so on. We extend a theorem by M. G. Krein on symmetrizable operators and a result by M. Mbekhta on reduced minimum modulus.Fil: Arias, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; ArgentinaFil: Corach, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; ArgentinaFil: Gonzalez, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentin

Linguistic and cultural crisis in Galicia, Spain.

To truly understand Spain, one must have more than just a basic knowledge of the country\u27s physical features or general traditions. If one investigates further into the history of ethnology of the name that is Spain, one discovers an intricate network of individual worlds that somehow revolve around one center, Madrid. Each patria chica or miniature country is a product of its location within the Peninsula, and each conserves its own institutions, values, and idiosyncracies. Today, the autonomous regions of Spain maintain and cherish their individuality with a certain degree of liberty thanks to the Constitution of 1978. Soon after the Reconquest of Iberia, the Catholic Sovereigns attained the unity of Spain. Consequently, the Castilian dialect of Latin became the official language of Spain and its overseas territories. The central power of Castile began its persecution of the regions. Castile succeeded greatly in homogenizing Spain by suppressing the very source of identity of its ethnic peoples--language. The installation of the Castilian language marked a new era in Spanish history. The linguistic supremacy of Castilian effectively arrested the cultural growth of the atrias chicas until very recently. Ample evidence of this is the virtual loss of the Leonese, Aragonese, Asturian, Navarrese, and Andalusian dialects of Latin along with the 400-year-old dialectalization of the Galician, Catalan, and Basque languages. Castilian dominance of Spain greatly degraded the state of education in Catalonia, Euzkadi, and Galicia. Not only did people from these regions lose an enormous part of their heritage, but Galicia, in particular, became the unwilling victim of generations of illiteracy and poverty. The year 1975 has come to represent the renaissance of the ethnic Spanish regions. Today, the historic autonomies of Spain can finally step out of the Castilian shadow and rediscover their pasts. One objective for them is certain--they must place their own languages at the forefront of their efforts to preserve their cultures. Their languages are their past, present, and future. Just how they will use them in this age of increasing global unity may make the future an interesting new era in Spain\u27s history

Thermodynamic framework for information in nanoscale systems with memory

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Arias-Gonzalez, J. Ricardo. 2017. Thermodynamic Framework for Information in Nanoscale Systems with Memory. The Journal of Chemical Physics 147 (20). AIP Publishing: 205101. doi:10.1063/1.5004793 and may be found at https://doi.org/10.1063/1.5004793."[EN] Information is represented by linear strings of symbols with memory that carry errors as a result of their stochastic nature. Proofreading and edition are assumed to improve certainty although such processes may not be effective. Here, we develop a thermodynamic theory for material chains made up of nanoscopic subunits with symbolic meaning in the presence of memory. This framework is based on the characterization of single sequences of symbols constructed under a protocol and is used to derive the behavior of ensembles of sequences similarly constructed. We then analyze the role of proofreading and edition in the presence of memory finding conditions to make revision an effective process, namely, to decrease the entropy of the chain. Finally, we apply our formalism to DNA replication and RNA transcription finding that Watson and Crick hybridization energies with which nucleotides are branched to the template strand during the copying process are optimal to regulate the fidelity in proofreading. These results are important in applications of information theory to a variety of solid-state physical systems and other biomolecular processes. Published by AIP Publishing.This work was supported by the Spanish Ministry of Economy and Competitiveness (Grant No. MAT2015-71806-R).Arias-Gonzalez, JR. (2017). Thermodynamic framework for information in nanoscale systems with memory. The Journal of Chemical Physics. 147(20):1-10. https://doi.org/10.1063/1.5004793S11014720Bustamante, C., Cheng, W., & Mejia, Y. X. (2011). 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