Genetic diversity of maize (Zea mays L. ssp. mays) in communities of the western highlands of Guatemala: geographical patterns and processes.

This study concerns spatial genetic patterning, seed flow and the impact of modern varieties in maize populations in Chimaltenango, Guatemala. It uses a collection of 79 maize seed samples from farmers in the area and five samples derived from modern varieties. Bulked SSR markers employed with bulked samples (ten plants) were used. Genetic distances between populations based on these SSR data were used as a measure of co-ancestry. The study describes the genetic variation in space, assesses the association of maize diversity with spatial and environmental descriptors and quantitative traits, and provides a test of the impact of improved varieties. Maize diversity showed significant isolation-by-distance locally, but not regionally. This was interpreted as evidence for a difference between local and regional mechanisms of seed exchange; regional exchange is more related to innovation. There was also a significant association with altitude and ear/grain characteristics (related to racial classifications). Also, consistent evidence for the influence of modern varieties of maize was found, although its impact was limited spatially. It is argued that the spatial distributions of maize diversity are important to consider for germplasm collection, but should be seen as a recent outcome of dynamic processes

Conservation program for the canarian creole cattle

The Cattle census of the Canary Islands is about 20500 animals, of this the Canary Creole Cattle Breed is only the 15.8 p.100. The other part of the census is formed by another selected breeds for milk production. Until the beginning of this decade this authochtonous breed became into danger of extinction because the competence of these imported breeds. In many cases the local population were absorbed and the total number decreased. At present, with the participation of an specific farmer association (Asociación Canaria de Arrastre) and the Official Institutions, the census are stabilised and is possible to see the future survival of the breed. In this paper we present the results of the main studies that had been made for the official acknowledgement of the Breeders Association, the standard of the breed and the situation of the Conservation program.El censo de ganado vacuno en Canarias es de unas 20500 cabezas, el 15,8 p.100 de raza Canaria y el resto, en su mayoría, es ganado selecto de aptitud lechera. Hasta principios de los años noventa esta raza se vio en grave peligro de extinción por la presión que sobre ella ejercieron otras razas más seleccionadas. A partir de entonces, gracias al esfuerzo de la Asociación Canaria de Arrastre y el apoyo de las distintas administraciones de la Comunidad Autónoma Canaria, los censos se han estabilizado e inician su recuperación. En esta comunicación se recopilan los resultados de los principales trabajos llevados a cabo para el reconocimiento de la Asociación de Criadores de esta raza, su estándar racial, así como el programa para su conservación

Unbiased taxonomic annotation of metagenomic samples

The classification of reads from a metagenomic sample using a reference taxonomy is usually based on first mapping the reads to the reference sequences and then classifying each read at a node under the lowest common ancestor of the candidate sequences in the reference taxonomy with the least classification error. However, this taxonomic annotation can be biased by an imbalanced taxonomy and also by the presence of multiple nodes in the taxonomy with the least classification error for a given read. In this article, we show that the Rand index is a better indicator of classification error than the often used area under thereceiver operating characteristic (ROC) curve andF-measure for both balanced and imbalanced reference taxonomies, and we also address the second source of bias by reducing the taxonomic annotation problem for a whole metagenomic sample to a set cover problem, for which a logarithmic approximation can be obtained in linear time and an exact solution can be obtained by integer linear programming. Experimental results with a proof-of-concept implementation of the set cover approach to taxonomic annotation in a next release of the TANGO software show that the set cover approach further reduces ambiguity in the taxonomic annotation obtained with TANGO without distorting the relative abundance profile of the metagenomic sample.Peer ReviewedPostprint (published version

Calidad alimenticia y estabilidad oxidativa de pseudoplatystoma corruscans

De todos los tipos de carnes, la del pescado es la más susceptible a la autolisis, a la oxidación e hidrólisis de las grasas, y a la alteración por microorganismos. El surubí manchado (Pseudoplatystoma corruscans) es el pez de agua dulce más comercializado en el noreste argentino. Los ejemplares analizados provinieron del río Paraná, 27° 17´ 30´´ latitud sur y 58° 59 50 de longitud oeste. Las muestras se envasaron en películas de alta y baja permeabilidad al oxígeno y se almacenaron a 16 °C y 5 °C. Se realizaron determinaciones fisicoquímicas, UFC, Valor de peróxido y TBARS, cada 7 días en las muestras refrigeradas y cada 14 días en las congeladas. El recuento inicial de microorganismos fue de 1,25.10+05. Al cabo de 2 semanas las muestras refrigeradas ya no fueron aptas microbiológicamente para el consumo (1.10+07). Para atenuar el crecimiento microbiano y retardar la oxidación lipídica deben emplearse temperaturas de congelación y envases de baja permeabilidad al oxígeno.De todos los tipos de carnes, la del pescado es la más susceptible a la autolisis, a la oxidación e hidrólisis de las grasas, y a la alteración por microorganismos. El surubí manchado (Pseudoplatystoma corruscans) es el pez de agua dulce más comercializado en el noreste argentino. Los ejemplares analizados provinieron del río Paraná, 27° 17’ 30” latitud sur y 58° 59’ 50” de longitud oeste. Las muestras se envasaron en películas de alta y baja permeabilidad al oxígeno y se almacenaron a –16 °C y 5 °C. Se realizaron determinaciones fisicoquímicas, UFC, Valor de Peróxido y TBARS, cada 7 días en las muestras refrigeradas y cada 14 días en las congeladas. El recuento inicial de microorganismos fue de 1,25.10+05. Al cabo de 2 semanas las muestras refrigeradas ya no fueron aptas microbiológicamente para el consumo (1.10+07). Para atenuar el crecimiento microbiano y retardar la oxidación lipídica deben emplearse temperaturas de congelación y envases de baja permeabilidad al oxígeno.De todolos tipos de carnes, á do pescado é a máis susceptible á autolisis, á oxidación e hidrólisis das grasas, e á alteración por microorganismos. O surubí manchado (Pseudoplatystoma corruscans) e o peixe de auga dulce máis comercializado no noreste argentino. Os exemplares analizados proveñeron do río Paraná, 27° 17’ 30” latitude sur e 58° 59’ 50” lonxitude oeste. As mostras envasaronse en películas de alta e baixa permeabilidade ó oxíxeno e almacenaron-se a -16 °C e 5 °C. Realizaronse determinacións fisicoquímicas, UFC, Valor de Peróxido e TBARS, cada 7 días nas mostras refrixeradas e cada 14 días nas conxeladas. O reconto inicial de microorganismos foi de 1,25.10+05. O cabo de 2 semanas as mostras refrixeradas xa non foron aptas microbiolóxicamente para o consumo (1.10+07). Para atenuar o crecemento microbiano e retardar a oxidación lipídica deben emplearse temperaturas de conxelación e envases de baixa permeabilidade ó oxíxeno.Fil: Molina, M.R... Universidad Nacional del Nordeste. Facultad de Agroindustrias; ArgentinaFil: Garro, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Judis, Maria Alicia. Universidad Nacional del Nordeste. Facultad de Agroindustrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

AXA: a computer program for the management of the Canary Goat Group milking control programs

A computer program, developed in Clipper, for the management of the genealogical and productive information from the Canary Goat Group, is described. The two first sections of this program are planned for the males and females genealogical data arrangement. Third section is devised for the productive data storage. Fourth section is constructed for the emission of reports and finally, fifth section is a miscellaneous of utilities, where the connection with other programs must be highlighted. Also an exit control is enclosed. The basic purposes of this program aim the emission of official production reports for the Administration and farmers, and the information processing for its analysis in programs of genetic selection.Se describe un programa de ordenador, desarrollado en Clipper, para la gestión de la información genealógica y productiva de la Agrupación Caprina Canaria. Sus dos primeras secciones se ocupan de la organización de la información genealógica de machos y de hembras; la tercera de la información productiva; la cuarta de la elaboración de informes y la quinta es una miscelánea de utilidades y un control de salida, con conexión con otros programas. Las misiones básicas del programa se centran en la emisión de informes productivos oficiales, destinados a la administración y a los ganaderos, y la preparación de la información para su análisis en programas de selección genética

Implementation of a Markov Chain Monte Carlo method to inorganic aerosol modeling of observations from the MCMA-2003 campaign ? Part I: Model description and application to the La Merced site

International audienceThe equilibrium inorganic aerosol model ISORROPIA was embedded in a Markov Chain Monte Carlo algorithm to develop a powerful tool to analyze aerosol data and predict gas phase concentrations where these are unavailable. The method directly incorporates measurement uncertainty, prior knowledge, and provides a formal framework to combine measurements of different quality. The method was applied to particle- and gas-phase precursor observations taken at La Merced during the Mexico City Metropolitan Area (MCMA) 2003 Field Campaign and served to discriminate between diverging gas-phase observations of ammonia and predict gas-phase concentrations of hydrochloric acid. The model reproduced observations of particle-phase ammonium, nitrate, and sulfate well. The most likely concentrations of ammonia were found to vary between 4 and 26 ppbv, while the range for nitric acid was 0.1 to 55 ppbv. During periods where the aerosol chloride observations were consistently above the detection limit, the model was able to reproduce the aerosol chloride observations well and predicted the most likely gas-phase hydrochloric acid concentration varied between 0.4 and 5 ppbv. Despite the high ammonia concentrations observed and predicted by the model, when the aerosols were assumed to be in the efflorescence branch they are predicted to be acidic (pH~3)

Gold-decorated magnetic nanoparticles design for hyperthermia applications and as a potential platform for their surface-functionalization

The integration of noble metal and magnetic nanoparticles with controlled structures that can couple various specific effects to the different nanocomposite in multifunctional nanosystems have been found interesting in the field of medicine. In this work, we show synthesis route to prepare small Au nanoparticles of sizes = 3.9 ± 0.2 nm attached to Fe 3 O 4 nanoparticle cores ( = 49.2 ± 3.5 nm) in aqueous medium for potential application as a nano-heater. Remarkably, the resulted Au decorated PEI-Fe 3 O 4 (Au@PEI-Fe 3 O 4 ) nanoparticles are able to retain bulk magnetic moment M S = 82–84 Am 2 /kg Fe3O4 , with the Verwey transition observed at T V = 98 K. In addition, the in vitro cytotoxicity analysis of the nanosystem microglial BV2 cells showed high viability (>97.5%) to concentrate up to 100 µg/mL in comparison to the control samples. In vitro heating experiments on microglial BV2 cells under an ac magnetic field (H 0 = 23.87 kA/m; f = 571 kHz) yielded specific power absorption (SPA) values of SPA = 43 ± 3 and 49 ± 1 μW/cell for PEI-Fe 3 O 4 and Au@PEI-Fe 3 O 4 NPs, respectively. These similar intracellular SPA values imply that functionalization of the magnetic particles with Au did not change the heating efficiency, providing at the same time a more flexible platform for multifunctional functionalization.Fil: León Félix, L.. Universidade do Brasília; Brasil. Universidad de Zaragoza; EspañaFil: Sanz, B.. Nb Nanoscale Biomagnetics S.l.; EspañaFil: Sebastián, V.. Universidad de Zaragoza; España. Centro de Investigación en Red en Bioingeniería; EspañaFil: Torres Molina, Teobaldo Enrique. Universidad de Zaragoza; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sousa, Marcelo Henrique. Universidade do Brasília; BrasilFil: Coaquira, J. A. H.. Universidade do Brasília; BrasilFil: Ibarra, M.R.. Universidad de Zaragoza; EspañaFil: Goya, Gerardo Fabian. Universidad de Zaragoza; Españ

Globally-Linked Vortex Clusters in Trapped Wave Fields

We put forward the existence of a rich variety of fully stationary vortex structures, termed H-clusters, made of an increasing number of vortices nested in paraxial wave fields confined by trapping potentials. However, we show that the constituent vortices are globally linked, rather than products of independent vortices. Also, they always feature a monopolar global wave front and exist in nonlinear systems, such as Bose-Einstein condensates. Clusters with multipolar global wave fronts are non-stationary or at best flipping.Comment: 4 pages, 5 PostScript figure

Implementation of a Markov Chain Monte Carlo method to inorganic aerosol modeling of observations from the MCMA-2003 campaign ? Part II: Model application to the CENICA, Pedregal and Santa Ana sites

International audienceA Markov Chain Monte Carlo model for integrating the observations of inorganic species with a thermodynamic equilibrium model was presented in Part I of this series. Using observations taken at three ground sites, i.e. a residential, industrial and rural site, during the MCMA-2003 campaign in Mexico City, the model is used to analyze the inorganic particle and ammonia data and to predict gas phase concentrations of nitric and hydrochloric acid. In general, the model is able to accurately predict the observed inorganic particle concentrations at all three sites. The agreement between the predicted and observed gas phase ammonia concentration is excellent. The NOz concentration calculated from the NOy, NO and NO2 observations is of limited use in constraining the gas phase nitric acid concentration given the large uncertainties in this measure of nitric acid and additional reactive nitrogen species. Focusing on the acidic period of 9?11 April identified by Salcedo et al. (2006), the model accurately predicts the particle phase observations during this period with the exception of the nitrate predictions after 10:00 a.m. (Central Daylight Time, CDT) on 9 April, where the model underpredicts the observations by, on average, 20%. This period had a low planetary boundary layer, very high particle concentrations, and higher than expected nitrogen dioxide concentrations. For periods when the particle chloride observations are consistently above the detection limit, the model is able to both accurately predict the particle chloride mass concentrations and provide well-constrained HCl (g) concentrations. The availability of gas-phase ammonia observations helps constrain the predicted HCl (g) concentrations. When the particles are aqueous, the most likely concentrations of HCl (g) are in the sub-ppbv range. The most likely predicted concentration of HCl (g) was found to reach concentrations of order 10 ppbv if the particles are dry. Finally, the atmospheric relevance of HCl (g) is discussed in terms of its indicator properties for the possible influence of chlorine-mediated photochemistry in Mexico City

Evolution of wave packets in quasi-1D and 1D random media: diffusion versus localization

We study numerically the evolution of wavepackets in quasi one-dimensional random systems described by a tight-binding Hamiltonian with long-range random interactions. Results are presented for the scaling properties of the width of packets in three time regimes: ballistic, diffusive and localized. Particular attention is given to the fluctuations of packet widths in both the diffusive and localized regime. Scaling properties of the steady-state distribution are also analyzed and compared with theoretical expression borrowed from one-dimensional Anderson theory. Analogies and differences with the kicked rotator model and the one-dimensional localization are discussed.Comment: 32 pages, LaTex, 11 PostScript figure