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  • 1
    Language: English
    In: Journal of Environmental Radioactivity, August, 2014, Vol.134, p.109(5)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvrad.2014.03.005 Byline: Michael Schubert, Juergen Kopitz, StanisAaw ChaAupnik Abstract: Radon is used as environmental tracer in a wide range of applications particularly in aquatic environments. If liquid scintillation counting (LSC) is used as detection method the radon has to be transferred from the water sample into a scintillation cocktail. Whereas the volume of the cocktail is generally given by the size of standard LSC vials (20 ml) the water sample volume is not specified. Aim of the study was an optimization of the water sample volume, i.e. its minimization without risking a significant decrease in LSC count-rate and hence in counting statistics. An equation is introduced, which allows calculating the A[sup.2]A[sup.2]A[sup.2]Rn concentration that was initially present in a water sample as function of the volumes of water sample, sample flask headspace and scintillation cocktail, the applicable radon partition coefficient, and the detected count-rate value. It was shown that water sample volumes exceeding about 900 ml do not result in a significant increase in count-rate and hence counting statistics. On the other hand, sample volumes that are considerably smaller than about 500 ml lead to noticeably lower count-rates (and poorer counting statistics). Thus water sample volumes of about 500-900 ml should be chosen for LSC radon-in-water detection, if 20 ml vials are applied. Author Affiliation: (a) Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany (b) Universitatsklinikum Heidelberg, Im Neuenheimer Feld 672, 69120 Heidelberg, Germany (c) Silesian Centre for Environmental Radioactivity, Central Mining Institute, Pl. Gwarkow, 140-166 Katowice, Poland Article History: Received 27 November 2013; Revised 7 February 2014; Accepted 9 March 2014
    Keywords: Tracers (Chemistry) ; Water
    ISSN: 0265-931X
    Source: Cengage Learning, Inc.
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  • 2
    Language: English
    In: 2012, Vol.7(11), p.e50030
    Description: Most proteins of the TRIM family (also known as RBCC family) are ubiquitin ligases that share a peculiar protein structure, characterized by including an N-terminal RING finger domain closely followed by one or two B-boxes. Additional protein domains found at their C termini have been used to classify TRIM proteins into classes. TRIMs are involved in multiple cellular processes and many of them are essential components of the innate immunity system of animal species. In humans, it has been shown that mutations in several TRIM-encoding genes lead to diverse genetic diseases and contribute to several types of cancer. They had been hitherto detected only in animals. In this work, by comprehensively analyzing the available diversity of TRIM and TRIM-like protein sequences and evaluating their evolutionary patterns, an improved classification of the TRIM family is obtained. Members of one of the TRIM subfamilies defined, called Subfamily A, turn to be present not only in animals, but also in many other eukaryotes, such as fungi, apusozoans, alveolates, excavates and plants. The rest of subfamilies are animal-specific and several of them originated only recently. Subfamily A proteins are characterized by containing a MATH domain, suggesting a potential evolutionary connection between TRIM proteins and a different type of ubiquitin ligases, known as TRAFs, which contain quite similar MATH domains. These results indicate that the TRIM family emerged much earlier than so far thought and contribute to our understanding of its origin and diversification. The structural and evolutionary links with the TRAF family of ubiquitin ligases can be experimentally explored to determine whether functional connections also exist.
    Keywords: Research Article ; Biology ; Plant Biology ; Evolutionary Biology ; Biochemistry
    E-ISSN: 1932-6203
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  • 3
    Language: English
    In: PLoS ONE, 2012, Vol.7(4), p.e35111
    Description: Higher vertebrates use similar genetic tools to derive very different facial features. This diversity is believed to occur through temporal, spatial and species-specific changes in gene expression within cranial neural crest (NC) cells. These contribute to the facial skeleton and contain species-specific information that drives morphological variation. A few signaling molecules and transcription factors are known to play important roles in these processes, but little is known regarding the role of micro-RNAs (miRNAs). We have identified and compared all miRNAs expressed in cranial NC cells from three avian species (chicken, duck, and quail) before and after species-specific facial distinctions occur. We identified 170 differentially expressed miRNAs. These include thirty-five novel chicken orthologs of previously described miRNAs, and six avian-specific miRNAs. Five of these avian-specific miRNAs are conserved over 120 million years of avian evolution, from ratites to galliforms, and their predicted target mRNAs include many components of Wnt signaling. Previous work indicates that mRNA gene expression in NC cells is relatively static during stages when the beak acquires species-specific morphologies. However, miRNA expression is remarkably dynamic within this timeframe, suggesting that the timing of specific developmental transitions is altered in birds with different beak shapes. We evaluated one miRNA:mRNA target pair and found that the cell cycle regulator p27 KIP1 is a likely target of miR-222 in frontonasal NC cells, and that the timing of this interaction correlates with the onset of phenotypic variation. Our comparative genomic approach is the first comprehensive analysis of miRNAs in the developing facial primordial, and in species-specific facial development.
    Keywords: Research Article ; Biology ; Genetics And Genomics ; Molecular Biology ; Developmental Biology ; Evolutionary Biology
    E-ISSN: 1932-6203
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  • 4
    Language: English
    In: Current Biology, 21 August 2012, Vol.22(16), pp.R641-R643
    Description: How can organisms silence deleterious gene loci? A recent study has shed light on a very brute mechanism in a jawless vertebrate: the irreversible deletion of massive chunks of genomic DNA.
    Keywords: Biology
    ISSN: 0960-9822
    E-ISSN: 1879-0445
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  • 5
    In: PLoS ONE, 2015, Vol.10(8)
    Description: Meprins are astacin metalloproteases with a characteristic, easily recognizable structure, given that they are the only proteases with both MAM and MATH domains plus a transmembrane region. So far assumed to be vertebrate-specific, it is shown here, using a combination of evolutionary and genomic analyses, that meprins originated before the urochordates/vertebrates split. In particular, three genes encoding structurally typical meprin proteins are arranged in tandem in the genome of the urochordate Ciona intestinalis . Phylogenetic analyses showed that the protease and MATH domains present in the meprin-like proteins encoded by the Ciona genes are very similar in sequence to the domains found in vertebrate meprins, which supports them having a common origin. While many vertebrates have the two canonical meprin-encoding genes orthologous to human MEP1A and MEP1B (which respectively encode for the proteins known as meprin α and meprin β), a single gene has been found so far in the genome of the chondrichthyan fish Callorhinchus milii , and additional meprin-encoding genes are present in some species. Particularly, a group of bony fish species have genes encoding highly divergent meprins, here named meprin-F. Genes encoding meprin-F proteins, derived from MEP1B genes, are abundant in some species, as the Amazon molly, Poecilia formosa , which has 7 of them. Finally, it is confirmed that the MATH domains of meprins are very similar to the ones in TRAF ubiquitin ligases, which suggests that meprins originated when protease and TRAF E3-encoding sequences were combined.
    Keywords: Research Article
    E-ISSN: 1932-6203
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  • 6
    Language: English
    In: PLoS ONE, 2012, Vol.7(2), p.e31902
    Description: Cnidarians are characterized by the presence of stinging cells containing nematocysts, a sophisticated injection system targeted mainly at prey-capture and defense. In the anthozoan subclass Octocorallia nematocytes have been considered to exist only in low numbers, to be small, and all of the ancestral atrichous-isorhiza type. This study, in contrast, revealed numerous nematocytes in the octocoral Heteroxenia fuscescens . The study demonstrates the applicability of cresyl-violet dye for differential staining and stimulating discharge of the nematocysts. In addition to the atrichous isorhiza-type of nematocysts, a novel type of macrobasic-mastigophore nematocysts was found, featuring a shaft, uniquely comprised of three loops and densely packed arrow-like spines. In contrast to the view that octocorals possess a single type of nematocyst, Heteroxenia fuscescens features two distinct types, indicating for the first time the diversification and complexity of nematocysts for Octocorallia.
    Keywords: Research Article ; Biology ; Earth Sciences ; Physiology ; Marine And Aquatic Sciences ; Evolutionary Biology
    E-ISSN: 1932-6203
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  • 7
    Language: English
    In: European Journal of Applied Physiology, 2012, Vol.112(7), pp.2475-2482
    Description: The aim of this study was to study if accuracy in sensorimotor control and cortical activity was influenced after induced fatigue during a knee joint reproduction task. Twelve volunteers performed a sensorimotor task before, directly after and 60 min after a prolonged exhaustive exercise protocol. The task consisted of an active reproduction of a target knee angle. After three practice trials, visual feedback was taken and the task was performed for 10 repetitions at a suitable pace. Reproduction accuracy was analyzed and EEG raw data were obtained from the frontal, central, temporal, parietal and occipital scalp locations during the task. The average power spectra in theta and alpha frequencies were computed across conditions for each participant. Task accuracy decreases significantly related to fatigue and increases after recovery. This is accompanied by a significant decrease in frontal theta, alpha-1 and alpha-2 frequencies after inducing fatigue. The power values in all frequency bands recovered after 60 min. Sensorimotor control was influenced by induced fatigue, which could be demonstrated in behavior and brain activity. Characteristics of brain activity demonstrated an increase in theta and a decrease in alpha-1 and alpha-2 frequency band power. The changes were discussed related to attentional recourses, alertness and somatosensory information processing mechanisms.
    Keywords: Exhaustive exercise ; Proprioception ; Joint position sense ; EEG ; Cortical activity
    ISSN: 1439-6319
    E-ISSN: 1439-6327
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  • 8
    Language: English
    In: PLoS ONE, 2012, Vol.7(7), p.e40172
    Description: Extracellular matrices regulate biological processes at the level of cells, tissues, and in some cases, entire multicellular organisms. The subphylum Urochordata exemplifies the latter case, where animals are partially or completely enclosed in “houses” or “tunics”. Despite this common strategy, we show that the house proteome of the appendicularian, Oikopleura , has very little in common with the proteome of the sister class, ascidian, Ciona . Of 80 identified house proteins (oikosins), ∼half lack domain modules or similarity to known proteins, suggesting de novo appearance in appendicularians. Gene duplication has been important in generating almost 1/3 of the current oikosin complement, with serial duplications up to 8 paralogs in one family. Expression pattern analyses revealed that individual oikosins are produced from specific fields of cells within the secretory epithelium, but in some cases, migrate up to at least 20 cell diameters in extracellular space to combine in defined house structures. Interestingly, peroxidasin and secretory phospholipase A 2 domains, implicated in innate immune defence are secreted from the anlage associated with the food-concentrating filter, suggesting that this extra-organismal structure may play, in part, such a role in Oikopleura . We also show that sulfation of proteoglycans is required for the hydration and inflation of pre-house rudiments into functional houses. Though correct proportioning in the production of oikosins would seem important in repetitive assembly of the complex house structure, the genomic organization of oikosin loci appears incompatible with common enhancers or locus control regions exerting such a coordinate regulatory role. Thus, though all tunicates employ extracellular matrices based on a cellulose scaffold as a defining feature of the subphylum, they have evolved radically different protein compositions associated with this common underlying structural theme.
    Keywords: Research Article ; Biology ; Genetics And Genomics ; Developmental Biology ; Evolutionary Biology ; Biochemistry
    E-ISSN: 1932-6203
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  • 9
    Language: English
    In: 2012, Vol.7(8), p.e44083
    Description: We show using the most complete phylogeny of one of the most species-rich orders of vertebrates (Gobiiformes), and calibrations from the rich fossil record of teleost fishes, that the genus Typhleotris , endemic to subterranean karst habitats in southwestern Madagascar, is the sister group to Milyeringa , endemic to similar subterranean systems in northwestern Australia. Both groups are eyeless, and our phylogenetic and biogeographic results show that these obligate cave fishes now found on opposite ends of the Indian Ocean (separated by nearly 7,000 km) are each others closest relatives and owe their origins to the break up of the southern supercontinent, Gondwana, at the end of the Cretaceous period. Trans-oceanic sister-group relationships are otherwise unknown between blind, cave-adapted vertebrates and our results provide an extraordinary case of Gondwanan vicariance.
    Keywords: Research Article ; Biology ; Earth Sciences ; Genetics And Genomics ; Marine And Aquatic Sciences ; Evolutionary Biology
    E-ISSN: 1932-6203
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  • 10
    Language: English
    In: Pharmacogenomics, December 2014, Vol.15(16), pp.1943-6
    Keywords: Cancer Genomics ; Co-Occurrent Mutations ; Data Mining ; Data-Driven Analyses ; Mutual Exclusivity ; Synthetic Lethality ; Genomics ; Precision Medicine ; Neoplasms -- Genetics
    ISSN: 14622416
    E-ISSN: 1744-8042
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