244 research outputs found

    Improving Nutrient Supply of Grassland Soil

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    In the Southern corner of the Eastern Carpathian Mountains is located the hilly region of Barcaság. The total agricultural area is 180 thousand ha of which 90 thousand ha is grassland. The maximum yield of natural grassland does not exceed 1.2 t ha-1 hay. The aim of this work is to find appropriate fertiliser and liming rates to increase the hay yield and improve the soil nutrient supply

    Novel polymorphic microsatellites from Guppy (Poecilia reticulata) and their utility in swordtails (Xiphophorus helleri)

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    Ten microsatellites were isolated from a genomic DNA library generated from guppy (Poecilia reticulata; Poecilidae) enriched for CA-repeats. All of the 10 microsatellites were polymorphic in guppy with an average allele number of 4.9/locus ranging from 2 to 14. All 10-primer pairs amplified specific products in green swordtail (Xiphophorus helleri) and 9 of the 10 microsatellites displayed polymorphism (average allele number: 4.1/locus with a scope between 2 and 8). Size range of alleles at most loci were similar between the two fish species. These microsatellites could be applied to breeding programs performed on these two species and possibly other poecilids and to genetic and ecological studies

    A new problem with cross-species amplification of microsatellites: Generation of non-homologous products

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    Microsatellites have been widely used in studies on population genetics, ecology and evolutionary biology. However, microsatellites are not always available for the species to be studied and their isolation could be time-consuming. In order to save time and effort researchers often rely on cross-species amplification. We revealed a new problem of microsatellite cross-species amplification in addition to size homoplasy by analyzing the sequences of electromorphs from seven catfish species belonging to three different families (Clariidae, Heteropneustidae and Pimelodidae). A total of 50 different electromorphs were amplified from the seven catfish species by using primers for 4 microsatellite loci isolated from the species Clarias batrachus. Two hundred and forty PCR-products representing all 50 electromorphs were sequenced and analyzed. Primers for two loci amplified specific products from orthologous loci in all species tested, whereas primers for the other two loci produced specific and polymorphic bands from some non-orthologous loci, even in closely related non-source species. Size homoplasy within the source species was not obvious, whereas extensive size homoplasy across species were detected at three loci, but not at the fourth one. These data suggest that amplification of products from non-orthologous loci and appearance of size homoplasy by cross-amplification are locus dependent, and do not reflect phylogenetic relationship. Amplification of non-orthologous loci and appearance of size homoplasy will lead to obvious complications in phylogenetic interference, population genetic and evolutionary studies. Therefore, we propose that sequence analysis of cross-amplification products should be conducted prior to application of cross-species amplification of microsatellites

    Neural Variability and Sampling-Based Probabilistic Representations in the Visual Cortex

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    Neural responses in the visual cortex are variable, and there is now an abundance of data characterizing how the magnitude and structure of this variability depends on the stimulus. Current theories of cortical computation fail to account for these data; they either ignore variability altogether or only model its unstructured Poisson-like aspects. We develop a theory in which the cortex performs probabilistic inference such that population activity patterns represent statistical samples from the inferred probability distribution. Our main prediction is that perceptual uncertainty is directly encoded by the variability, rather than the average, of cortical responses. Through direct comparisons to previously published data as well as original data analyses, we show that a sampling-based probabilistic representation accounts for the structure of noise, signal, and spontaneous response variability and correlations in the primary visual cortex. These results suggest a novel role for neural variability in cortical dynamics and computations.European Union-FP7 (Marie Curie Intra-European Fellowship, Marie Curie CIG), Hungarian Academy of Sciences (Lendulet Award), Swartz Foundation, Swiss National Science Foundation, National Science Foundation, Wellcome Trus

    Mapping QTL for sex and growth traits in Salt-Tolerant Tilapia (Oreochromis spp. X O. mossambicus)

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    In aquaculture, growth and sex are economically important traits. To accelerate genetic improvement in increasing growth in salt-tolerant tilapia, we conducted QTL mapping for growth traits and sex with an F2 family, including 522 offspring and two parents. We used 144 polymorphic microsatellites evenly covering the genome of tilapia to genotype the family. QTL analyses were carried out using interval mapping for all individuals, males and females in the family, respectively. Using all individuals, three suggestive QTL for body weight, body length and body thickness respectively were detected in LG20, LG22 and LG12 and explained 2.4% to 3.1% of phenotypic variance (PV). When considering only males, five QTL for body weight were detected on five LGs, and explained 4.1 to 6.3% of PV. Using only females from the F2 family, three QTL for body weight were detected on LG1, LG6 and LG8, and explained 7.9–14.3% of PV. The QTL for body weight in males and females were located in different LGs, suggesting that in salt-tolerant tilapia, different set of genes ‘switches’ control the growth in males and females. QTL for sex were mapped on LG1 and LG22, indicating multigene sex determination in the salt-tolerant tilapia. This study provides new insights on the locations and effects of QTL for growth traits and sex, and sets the foundation for fine mapping for future marker-assisted selection for growth and sex in salt-tolerant tilapia aquaculture

    Altered mitochondrial response to activation of T-cells in neonate

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    Mitochondrial functions have a major impact on T-cell functionality. In this study we characterized whether mitochondrial function in the neonatal T-cells differs from that in the adult T-cells during short T-cell activation. Methods: We used fow cytometry methods to test mitochondrial mass and to monitor mitochondrial Ca2+ levels, mitochondrial potential and superoxide generation in parallel with cytoplasmic Ca2+ levels during phythohaemagglutinine-induced activation of CD4+ and CD8+ T-cells of 12 term neonates and 11 healthy adults. Results: Baseline mitochondrial mass of CD4+ and CD8+ cells was lower in the neonate than in the adult. In comparison with the adult, neonatal resting CD4+ T-cells had lower cytoplasmic Ca2+ levels and this was associated with normal activation induced Ca2+-response. During short-term activation cytoplasmic Ca2+-response was lower in neonatal than in adult CD8+ T-cells. Mitochondrial Ca2+ uptake was increased in CD4+ neonatal T cells while it decreased in CD8+ T-cells. Mitochondrial depolarization was increased in CD4+ and decreased in CD8+ neonatal T-cells compared to adults. Superoxide generation was higher and equal in neonatal CD4+ and CD8+ cells, respectively, compared to the adult ones. Conclusion: Our data suggest that neonatal T-cells exhibit marked differences in mitochondrial function and superoxide generation compared to adult T-cells

    Altered mitochondrial response to activation of T-cells in neonate

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    Mitochondrial functions have a major impact on T-cell functionality. In this study we characterized whether mitochondrial function in the neonatal T-cells differs from that in the adult T-cells during short T-cell activation. METHODS: We used fow cytometry methods to test mitochondrial mass and to monitor mitochondrial Ca(2+) levels, mitochondrial potential and superoxide generation in parallel with cytoplasmic Ca(2+) levels during phythohaemagglutinine-induced activation of CD4+ and CD8+ T-cells of 12 term neonates and 11 healthy adults. RESULTS: Baseline mitochondrial mass of CD4+ and CD8+ cells was lower in the neonate than in the adult. In comparison with the adult, neonatal resting CD4+ T-cells had lower cytoplasmic Ca(2+) levels and this was associated with normal activation induced Ca(2+)-response. During short-term activation cytoplasmic Ca(2+)-response was lower in neonatal than in adult CD8+ T-cells. Mitochondrial Ca(2+) uptake was increased in CD4+ neonatal T cells while it decreased in CD8+ T-cells. Mitochondrial depolarization was increased in CD4+ and decreased in CD8+ neonatal T-cells compared to adults. Superoxide generation was higher and equal in neonatal CD4+ and CD8+ cells, respectively, compared to the adult ones. CONCLUSION: Our data suggest that neonatal T-cells exhibit marked differences in mitochondrial function and superoxide generation compared to adult T-cells
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