4,038 research outputs found

    Global transcriptome profiling reveals molecular mechanisms of metal tolerance in a chronically exposed wild population of brown trout.

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    addresses: Biosciences, College of Life & Environmental Sciences, Geoffrey Pope Building, University of Exeter , Exeter, EX4 4QD. [email protected] © 2013 American Chemical SocietyThis is an open access article that is freely available in ORE or from the publisher's web site. http://pubs.acs.org/doi/abs/10.1021/es401380p Please cite the published versioncontacts: T.M.U.W.: E-mail [email protected], phone +44 (0)1392 724677, fax +44 (0)1392 263434. E.M.S.: E-mail E.Santos@ exeter.ac.uk, phone +44 (0)1392 264607, fax +44 (0)1392 263434.Worldwide, a number of viable populations of fish are found in environments heavily contaminated with metals, including brown trout (Salmo trutta) inhabiting the River Hayle in South-West of England. This population is chronically exposed to a water-borne mixture of metals, including copper and zinc, at concentrations lethal to naïve fish. We aimed to investigate the molecular mechanisms employed by the River Hayle brown trout to tolerate high metal concentrations. To achieve this, we combined tissue metal analysis with whole-transcriptome profiling using RNA-seq on an Illumina platform. Metal concentrations in the Hayle trout, compared to fish from a relatively unimpacted river, were significantly increased in the gills, liver and kidney (63-, 34- and 19-fold respectively), but not the gut. This confirms that these fish can tolerate considerable metal accumulation, highlighting the importance of these tissues in metal uptake (gill), storage and detoxification (liver, kidney). We sequenced, assembled and annotated the brown trout transcriptome using a de novo approach. Subsequent gene expression analysis identified 998 differentially expressed transcripts and functional analysis revealed that metal- and ion-homeostasis pathways are likely to be the most important mechanisms contributing to the metal tolerance exhibited by this population.Natural Environment Research Council (NERC

    Conditioned stochastic particle systems and integrable quantum spin systems

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    We consider from a microscopic perspective large deviation properties of several stochastic interacting particle systems, using their mapping to integrable quantum spin systems. A brief review of recent work is given and several new results are presented: (i) For the general disordered symmectric exclusion process (SEP) on some finite lattice conditioned on no jumps into some absorbing sublattice and with initial Bernoulli product measure with density ρ\rho we prove that the probability Sρ(t)S_\rho(t) of no absorption event up to microscopic time tt can be expressed in terms of the generating function for the particle number of a SEP with particle injection and empty initial lattice. Specifically, for the symmetric simple exclusion process on Z\mathbb Z conditioned on no jumps into the origin we obtain the explicit first and second order expansion in ρ\rho of Sρ(t)S_\rho(t) and also to first order in ρ\rho the optimal microscopic density profile under this conditioning. For the disordered ASEP on the finite torus conditioned on a very large current we show that the effective dynamics that optimally realizes this rare event does not depend on the disorder, except for the time scale. For annihilating and coalescing random walkers we obtain the generating function of the number of annihilated particles up to time tt, which turns out to exhibit some universal features.Comment: 25 page

    Cysticidal therapy - Impact on seizure control in epilepsy associated with neurocysticercosis

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    Objective: To evaluate the clinical features and seizure control of epilepsy related to neurocysticercosis. Method: 18 patients with partial epilepsy and neurocysticercosis were treated with albendazol or praziquantel and followed from 3 months to 12 years. We analyzed results from the CSF exam, interictal electroencephalogram (EEG), head computerized tomography and/or magnetic resonance imaging. Results: The patients' mean age was 36.4 years. The mean duration of epilepsy was 16 years, 83% patients had simple partial seizures; 17% had complex partial seizures. All patients underwent routine EEGs; 62% had abnormalities and 38% were normal. A relationship was observed between focal EEG abnormality and the location of cyst in 28% of the patients. The CSF exams showed pleocytosis in 33% of the patients, and 28% had elevated protein levels. Only 22% of patients had positive titer for cysticercosis in the CSF. In all patients who had somatosensory and special sensory seizures there was a relationship between location of the cysts and seizure semiology (n = 11). After cysticidal therapy, 83% patients had a significant improvement in controlling seizures. Conclusion: In this group, we found a predominance of simple partial seizures and a relationship between somatosensory and special sensory seizures and the location of the cysts. Cysticidal therapy was effective in controlling seizures in these patients and should be considered for patients with partial seizures and semiology related to cyst location.5841014102

    In silico identification of potential chaperone genes that belong to type III and type IV secretion systems in Xanthomonas axonopodis pv citri

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    The secretion of bacterial virulence factors and flagellar components requires the assistance of specific type III and flagellar chaperones. Standard computational annotation of the genome of Xanthomonas axonopodis pv citri, a plant pathogen that causes citrus canker, initially did not identify any genes belonging to these chaperone categories since the primary sequence homology between them was very low. However, in a search for hypothetical proteins with characteristics similar to these chaperones, we have now identified 30 chromosomal and 10 plasmidial potential genes encoding chaperones belonging to types III/IV, and flagellar secretion systems in this organism. The significance of these findings is discussed.28232132

    Variability of coastal and ocean water temperature in the upper 700 m along the western Iberian Peninsula from 1975 to 2006

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    Temperature is observed to have different trends at coastal and ocean locations along the western Iberian Peninsula from 1975 to 2006, which corresponds to the last warming period in the area under study. The analysis was carried out by means of the Simple Ocean Data Assimilation (SODA). Reanalysis data are available at monthly scale with a horizontal resolution of 0.5° × 0.5° and a vertical resolution of 40 levels, which allows obtaining information beneath the sea surface. Only the first 21 vertical levels (from 5.0 m to 729.35 m) were considered here, since the most important changes in heat content observed for the world ocean during the last decades, correspond to the upper 700 m. Warming was observed to be considerably higher at ocean locations than at coastal ones. Ocean warming ranged from values on the order of 0.3 °C dec(-1) near surface to less than 0.1 °C dec(-1) at 500 m, while coastal warming showed values close to 0.2 °C dec(-1) near surface, decreasing rapidly below 0.1 °C dec(-1) for depths on the order of 50 m. The heat content anomaly for the upper 700 m, showed a sharp increase from coast (0.46 Wm(-2)) to ocean (1.59 Wm(-2)). The difference between coastal and ocean values was related to the presence of coastal upwelling, which partially inhibits the warming from surface of near shore water.publishe

    CO2 laser and fluoride on the inhibition of root caries-an in vitro microbial model

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)An increase in the dental caries prevalence on root surfaces has been observed mainly in elderly. This research assessed, in vitro, the effectiveness of a pulsed CO2 (lambda = 10.6 mu m) laser associated or not with fluoride, in reducing human root dentine demineralization in conditions that mimic an oral high cariogenic challenge. After sterilization, root dentine specimens were randomly assigned into 6 groups (n = 30), in triplicate. The groups were Control (C), Streptococcus mutans (SM), Fluoride (F), Laser (L), Fluoride + laser (FL), and Laser + fluoride (LF). Except for the control group, all the specimens were inoculated with SM and immersed 3 times a day in a 40% sucrose bath. After a 7-day cariogenic challenge, the mineral loss and lesion depth were evaluated by transverse microradiography and fluoride in the biofilm was determined using an ion-selective electrode. Results were statistically analyzed by analysis of variance, at 5% of significance level. For groups C, SM, F, L, FL and LF, the means (standard-deviation) of mineral loss were 816.3 (552.5)(a), 3291.5 (1476.2)(c), 2508.5 (1240.5)(bc), 2916.2 (1323.7)(c), 1839.7 (815.2)(b) and 1955.0 (1001.4)(b), respectively; while lesion depths were 39.6 (22.8)(a), 103.1 (38.9)(c), 90.3 (44.6)(bc), 91.7 (27.0)(bc), 73.3 (26.6)(b), 75.1 (35.2)(b), respectively (different superscript letters indicate significant differences among groups). In conclusion, irradiation of root dentine with a pulsed CO2 laser at fluency of 12.0 J/cm(2) was able to inhibit root surface demineralization only when associated with fluoride. No synergy effect on the inhibition of root dentine mineral loss was provided by the combination of fluoride application and laser irradiation.20918381843Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [201746/2007-7

    Planet Populations as a Function of Stellar Properties

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    Exoplanets around different types of stars provide a window into the diverse environments in which planets form. This chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to planet formation in protoplanetary disks. Giant planets occur more frequently around more metal-rich and more massive stars. These findings support the core accretion theory of planet formation, in which the cores of giant planets form more rapidly in more metal-rich and more massive protoplanetary disks. Smaller planets, those with sizes roughly between Earth and Neptune, exhibit different scaling relations with stellar properties. These planets are found around stars with a wide range of metallicities and occur more frequently around lower mass stars. This indicates that planet formation takes place in a wide range of environments, yet it is not clear why planets form more efficiently around low mass stars. Going forward, exoplanet surveys targeting M dwarfs will characterize the exoplanet population around the lowest mass stars. In combination with ongoing stellar characterization, this will help us understand the formation of planets in a large range of environments.Comment: Accepted for Publication in the Handbook of Exoplanet
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