Sheathless capillary electrophoresis-mass spectrometry for anionic metabolic profiling

The performance of CE coupled on-line to MS via a sheathless porous tip sprayer was evaluated for anionic metabolic profiling. A representative metabolite mixture and biological samples were used for the evaluation of various analytical parameters, such as peak efficiency (plate numbers), migration time and peak area repeatability, and LODs. The BGE, i.e. 10% acetic acid (pH 2.2), previously used for cationic metabolic profiling was now assessed for anionic metabolic profiling by using MS detection in negative ion mode. For test compounds, RSDs for migration times and peak areas were below 2 and 11%, respectively, and plate numbers ranged from 60 000 to 40 0000 demonstrating a high separation efficiency. Critical metabolites with low or no retention on reversed-phase LC could be efficiently separated and selectively analyzed by the sheathless CE-MS method. An injection volume of only circa 20 nL resulted in LODs between 10 and 200 nM (corresponding to an amount of 0.4-4 fmol), which was an at least tenfold improvement as compared to LODs obtained by conventional CE-MS approaches for these analytes. The methodology was applied to anionic metabolic profiling of glioblastoma cell line extracts. Overall, a sheathless CE-MS method has been developed for highly efficient and sensitive anionic metabolic profiling studies, which can also be used for cationic metabolic profiling studies by only switching the MS detection and separation voltage polarity.Analytical BioScience

Identification of novel miRNAs involved in cardiac repair following infarction in fetal and adolescent sheep hearts

Aims:Animal models have been used to show that there are critical molecular mechanisms that can be activated to induce myocardial repair at specific times in development. For example, specific miRNAs are critical for regulating the response to myocardial infarction (MI) and improving the response to injury. Manipulating these miRNAs in small animal models provides beneficial effects post-MI; however it is not known if these miRNAs are regulated similarly in large mammals. Studying a large animal where the timing of heart development in relation to birth is similar to humans may provide insights to better understand the capacity to repair a developing mammalian heart and its application to the adult heart. Methods:We used a sheep model of MI that included permanent ligation of the left anterior descending (LAD) coronary artery. Surgery was performed on fetuses (at 105 days gestation when all cardiomyocytes are mononucleated and proliferative) and adolescent sheep (at 6 months of age when all cardiomyocytes contribute to heart growth by hypertrophy). A microarray was utilized to determine the expression of known miRNAs within the damaged and undamaged tissue regions in fetal and adolescent hearts after MI. Results:73 miRNAs were up-regulated and 58 miRNAs were down-regulated significantly within the fetal infarct compared to remote cardiac samples. From adolescent hearts 69 non-redundant miRNAs were up-regulated and 63 miRNAs were down-regulated significantly in the infarct area compared to remote samples. Opposite differential expression profiles of 10 miRNAs within tissue regions (Infarct area, Border zone and Remote area of the left ventricle) occurred between the fetuses and adolescent sheep. These included miR-558 and miR-1538, which when suppressed using LNA anti-miRNAs in cell culture, increased cardiomyoblast proliferation. Conclusion:There were significant differences in miRNA responses in fetal and adolescent sheep hearts following a MI, suggesting that the modulation of novel miRNA expression may have therapeutic potential, by promoting proliferation or repair in a damaged heart.Mitchell C. Lock, Ross L. Tellam, Jack R. T. Darby, Jia Yin Soo, Doug A. Brooks, Mike Seed ... et al

Constraints on dark matter-nucleon effective couplings in the presence of kinematically distinct halo substructures using the DEAP-3600 detector

DEAP-3600 is a single-phase liquid argon detector aiming to directly detect weakly interacting massive particles (WIMPs), located at SNOLAB (Sudbury, Canada). After analyzing data taken during the first year of operation, a null result was used to place an upper bound on the WIMP-nucleon, spin-independent, isoscalar cross section. This study reinterprets this result within a nonrelativistic effective field theory framework and further examines how various possible substructures in the local dark matter halo may affect these constraints. Such substructures are hinted at by kinematic structures in the local stellar distribution observed by the Gaia satellite and other recent astronomical surveys. These include the Gaia Sausage (or Enceladus), as well as a number of distinct streams identified in recent studies. Limits are presented for the coupling strength of the effective contact interaction operators O1, O3, O5, O8, and O11, considering isoscalar, isovector, and xenonphobic scenarios, as well as the specific operators corresponding to millicharge, magnetic dipole, electric dipole, and anapole interactions. The effects of halo substructures on each of these operators are explored as well, showing that the O5 and O8 operators are particularly sensitive to the velocity distribution, even at dark matter masses above 100 GeV=c

Early colonization of littoral communities on polyurethane coated substrates: A field and laboratory study

Materials used for urbanized coastal structures often create a hard substra te ready to be colonized. Elastocoast, a new coastal protection material made from stones and polyurethane, is such a material. This study examined the recovery and growth during the winter of 2007-2008 of the biological community on two dykes in the Netherlands which were refurbished with Elastocoast at the beginning of the storm season, and describes an algal colonization experiment done with Elastocoast in the laboratory. In the field, 4 months after the cons truction of the Elastocoast top layer, dyke vegetation has returned, though strongly zonated and leaving large patches without any vegetation. Main algal species are Enteromorplta mi1tima and Fucus spiralis. Animals found on the Elastocoast layer mainly consisted of Littoriua sp. and Patella Vulgata. The Elastocoast pilots in the field were examined for 25 weeks, it is expected that the biological community will recover further when given enough time. The laboratory experiment showed that by colonization by micro-algae under favorable circumstances can be fast and substantial, by numerous micro algae and animals. Elastocoast therefore seems to be a material which allows community recovery to be fast and according to the typical vegetation of that area

Evidence for an osmoregulatory role of thyroid hormones in the freshwater mozambique tilapia Oreochromis mossambicus

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The spatial construct of social relations: social transformation in early Kaushi, Taiwan

This research attempts to extend the application of spatial analysis to the investigation of human agency in social relations. Marcos Llobera's research framework on modelling daily experience and social space showcases great potentials of utilising Geographic Information Systems (GIS) to explore the perception and behaviour of individual agents. By expanding Llobera's work and incorporating Tim Ingold's wayfaring theory to explore the human agency in the context of social relations, this research proposes a new analytical method to investigate social relations through the accumulation of intimate interactions. Exemplified with detailed analysis on two settlements of Kaushi people in Taiwan, the proposed analytical method demonstrates great strength and yields fruitful insights into their social structure and transformation. In addition, this method is particularly instrumental in unravelling specific relations between individuals, as well as between social groups. The application of this method on Kaushi settlements yielded fruitful insights of their social structure and transformation. On the other hand, the side products of this approach can be further employed to investigate the visual structure and movement intensity of a site, as well as to experiment alternative 'what if' scenarios relating to visibility, movement, and interaction. In sum, this research augments the potential of spatial analysis to explore human agency in a social context and lays out a further platform for the investigation of social relations at a settlement scale.This thesis is not currently available via ORA

Evidence-based alignment of conservation policies with remote sensing-enabled essential biodiversity variables

Nature conservation policies require up-to-date and accurate biodiversity monitoring. Innovative synoptic information products such as Remote Sensing-enabled Essential Biodiversity Variables (RS-enabled EBVs) could complement field observations in biodiversity monitoring. It is not clear however, how these scientific remote sensing products can be utilized for policy reporting. Agreement on the monitored geographic extent (area size and scale), as well as biodiversity attributes (composition, structure, and function), may provide a common'point of departure' for policymakers and the scientific community to develop and further improve monitoring. In this study, biodiversity indicators of 10 nature conservation policies and 50 RS-enabled EBVs were compared using non-parametric tests (chi-square and Mann-Whitney U). Our main finding is that policy indicators and RS-enabled EBVs are very similar in the spatial extent they address (mapping scale). However, most policy indicators are related to ecosystem structure while most of the RS-enabled EBVs are related to ecosystem function and ecosystem structure. RS-enabled EBVs have added value in monitoring of biodiversity, especially when looking at ecosystem functioning. Information on ecosystem functioning and structure provides evidence needed as input for policy development and management of biodiversity. However, to make this happen, a stronger focus on ecosystem functioning and structure with appropriate variables is needed, in policy requirements and target