36 research outputs found

    Identification and conservation of remnant genetic resources of brown trout in relict populations from Western Mediterranean streams

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    This is a post-peer-review, pre-copyedit version of an article published in Hydrobiologia. The final authenticated version is available online at: https://doi.org/10.1007/s10750-012-1402-8Brown trout is a cold-adapted freshwater species with restricted distribution to headwater streams in rivers of the South European peninsulas, where populations are highly vulnerable because Mediterranean regions are highly sensitive to the global climatic warming. Moreover, these populations are endangered due to the introgressive hybridization with cultured stocks. Individuals from six remnant populations in Western Mediterranean rivers were sequenced for the complete mitochondrial DNA control region and genotyped for 11 nuclear markers. Three different brown trout lineages were present in the studied region. Significant genetic divergence was observed among locations and a strong effect of genetic drift was suggested. An important stocking impact (close to 25%) was detected in the zone. Significant correlations between mitochondrial-based rates of hatchery introgression and water flow variation suggested a higher impact of stocked females in unstable habitats. In spite of hatchery introgression, all populations remained highly differentiated, suggesting that native genetic resources are still abundant. However, climatic predictions indicated that suitable habitats for the species in these rivers will be reduced and hence trout populations are highly endangered and vulnerable. Thus, management policies should take into account these predictions to design upstream refuge areas to protect remnant native trout in the regionThis study has been supported by the Generalitat Valenciana Autonomous Government (Spain) project (2008/CI446)S

    Effects of water pollution and river fragmentation on population genetic structure of invasive mosquitofish

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    We analyzed variation at the GPI-2 locus and eleven microsatellite loci of eastern mosquitofish Gambusia holbrooki populations introduced to the Ebro River (Spain), sampling above and below a dam (Flix Reservoir) where severe chronic pollution has been well documented. Allele frequency changes at the GPI-2 locus in the sites nearest to the polluted sediments agree with previous results from studies in mercury-exposed populations of this highly invasive fish. Genetic distinction of the mosquitofish collected close to the polluted sediments was detected at the GPI locus but also at the presumptive neutral microsatellite loci. Recent migration rates estimated from microsatellites indicated that around 30% of fish collected in a specific location were immigrants from upstream and downstream sources. Such high migration rates probably contribute to the mosquitofish's invasive success and suggest that the consequences on the mosquitofish regional genetic structured of high levels of water toxicants could be mediated by immigration from other sites, but the effect of pollutants on local diversity might be higher than observed here.info:eu-repo/semantics/acceptedVersio

    Proportions of Convective and Stratiform Precipitation Revealed in Water Isotope Ratios

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    Tropical and midlatitude precipitation is fundamentally of two types, spatially-limited and high-intensity convective or widespread and lower-intensity stratiform, owing to differences in vertical air motions and microphysical processes governing rain formation. These processes are difficult to observe or model and precipitation partitioning into rain types is critical for understanding how the water cycle responds to climate changes. Here, we combine two independent data sets – convective and stratiform precipitation fractions, derived from the Tropical Rainfall Measuring Mission satellite or synoptic cloud observations, and stable isotope and tritium compositions of surface precipitation, derived from a global network – to show that isotope ratios reflect rain type proportions and are negatively correlated with stratiform fractions. Condensation and riming associated with boundary layer moisture produces higher isotope ratios in convective rain, along with higher tritium when riming in deep convection occurs with entrained air at higher altitudes. Based on our data, stable isotope ratios can be used to monitor changes in the character of precipitation in response to periodic variability or changes in climate. Our results also provide observational constraints for an improved simulation of convection in climate models and a better understanding of isotope variations in proxy archives, such as speleothems and tropical ice

    Data Descriptor: Daily observations of stable isotope ratios of rainfall in the tropics

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    We present precipitation isotope data (δ2H and δ18O values) from 19 stations across the tropics collected from 2012 to 2017 under the Coordinated Research Project F31004 sponsored by the International Atomic Energy Agency. Rainfall samples were collected daily and analysed for stable isotopic ratios of oxygen and hydrogen by participating laboratories following a common analytical framework. We also calculated daily mean stratiform rainfall area fractions around each station over an area of 5° x 5° longitude/latitude based on TRMM/GPM satellite data. Isotope time series, along with information on rainfall amount and stratiform/convective proportions provide a valuable tool for rainfall characterisation and to improve the ability of isotope-enabled Global Circulation Models to predict variability and availability of inputs to fresh water resources across the tropics.Fil: Munksgaard, Niels C.. James Cook University; Australia. Charles Darwin University. School of Environmental Research; AustraliaFil: Kurita, Naoyuki. Nagoya University; JapónFil: Sánchez Murillo, Ricardo. Universidad Nacional; Costa RicaFil: Ahmed, Nasir. Bangladesh Atomic Energy Commission; BangladeshFil: Araguas, Luis. International Atomic Energy Agency (iaea); AustriaFil: Balachew, Dagnachew L.. International Atomic Energy Agency (iaea); AustriaFil: Bird, Michael I.. James Cook University; AustraliaFil: Chakraborty, Supriyo. Indian Institute of Tropical Meteorology; IndiaFil: Kien Chinh, Nguyen. Center for Nuclear Techniques; VietnamFil: Cobb, Kim M.. Georgia Institute of Technology; Estados UnidosFil: Ellis, Shelby A.. Georgia Institute of Technology; Estados UnidosFil: Esquivel Hernández, Germain. Universidad Nacional; Costa RicaFil: Ganyaglo, Samuel Y.. National Nuclear Research Institute; GhanaFil: Gao, Jing. Chinese Academy of Sciences; República de ChinaFil: Gastmans, Didier. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Kaseke, Kudzai F.. Indiana University-Purdue University Indianapolis; India. University of California Santa Barbara; Estados UnidosFil: Kebede, Seifu. Addis Ababa University; EtiopíaFil: Morales, Marcelo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Mueller, Moritz. Swinburne University of Technology; MalasiaFil: Poh, Seng Chee. Universiti Malaysia Terengganu; MalasiaFil: Santos, Vinícius dos. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Shaoneng, He. Nanyang Technological University; SingapurFil: Wang, Lixin. Indiana University-Purdue University Indianapolis; IndiaFil: Yacobaccio, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Zwart, Costijn. James Cook University; Australi

    Adquisicion de los contenidos isotopicos (18O y D) de las aguas subterraneas Variaciones en la atmosfera y en la zona no saturada del suelo

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    Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

    Visión y Robótica con Software Libre

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    En el siguiente trabajo se describe una metodología basada en el paradigma estructurado de desarrollo de sistemas del tipo simplificado con la finalidad de resolver una situación problemática conceptual en forma sencilla y eficiente. El procedimiento utilizado es la articulación de librerías de edición de video, software de robótica y un hardware mediante el lenguaje de programación ANSI C, herramienta de compilación para linkeo y depuración en plataforma GNU/Linux. Se logro suavizar la respuesta de control del algoritmo de seguimiento de un objeto mediante la utilización de un controlador proporcional integral derivativo debido a que la implementación del mismo logra acoplar la librería de edición de video y algoritmo de control con la respuesta inercial de la plataforma móvil.Sociedad Argentina de Informática e Investigación Operativ

    Genetic risks of supplementing trout populations with native stocks: A simulation case study from current pyrenean populations

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    The risks of supplementation must be examined to assess the genetic effects to native wild populations before full implementation or exclusion of programs that involve captive breeding and release. Real genetic data can be applied to simulations of genetic changes in populations of interest and subsequently used in risk assessment. Ancestral Mediterranean brown trout (Salmo trutta) lineages exhibit complex population structure among native populations. Genetically divergent Atlantic stocks were maintained and released in the Mediterranean rivers as recreational fish, which resulted in hybridization and introgression with local populations. Therefore, we designed a new supplementation program based on native stocks and evaluated the genetic risks associated with releasing native fish in recreational fisheries. Our simulation was delimited by the observed population genetic structure and available hatchery facilities in the study region. Supplementation with native stocks maintained estimates of gene diversity indexes (total diversity (HT), local diversity (HS), and population differentiation (GST)). However, simulations indicated that long-term supplementation significantly reduced genetic diversity among locations because of a homogenizing effect of populations along each management unit. Therefore, such reinforcements compromised the conservation of local genetic variation. Nevertheless, replacement of current foreign stocks with native stocks can be an important step towards promoting the value of preserving local diversity among anglers
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