116 research outputs found

    Fecal Metaproteomics Reveals Reduced Gut Inflammation and Changed Microbial Metabolism Following Lifestyle-Induced Weight Loss

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    Gut microbiota-mediated inflammation promotes obesity-associated low-grade inflammation, which represents a hallmark of metabolic syndrome. To investigate if lifestyle-induced weight loss (WL) may modulate the gut microbiome composition and its interaction with the host on a functional level, we analyzed the fecal metaproteome of 33 individuals with metabolic syndrome in a longitudinal study before and after lifestyle-induced WL in a well-defined cohort. The 6-month WL intervention resulted in reduced BMI (−13.7%), improved insulin sensitivity (HOMA-IR, −46.1%), and reduced levels of circulating hsCRP (−39.9%), indicating metabolic syndrome reversal. The metaprotein spectra revealed a decrease of human proteins associated with gut inflammation. Taxonomic analysis revealed only minor changes in the bacterial composition with an increase of the families Desulfovibrionaceae, Leptospiraceae, Syntrophomonadaceae, Thermotogaceae and Verrucomicrobiaceae. Yet we detected an increased abundance of microbial metaprotein spectra that suggest an enhanced hydrolysis of complex carbohydrates. Hence, lifestyle-induced WL was associated with reduced gut inflammation and functional changes of human and microbial enzymes for carbohydrate hydrolysis while the taxonomic composition of the gut microbiome remained almost stable. The metaproteomics workflow has proven to be a suitable method for monitoring inflammatory changes in the fecal metaproteome

    Mapping migrant territories as topological deformations of space

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    Our research uses the concept of “territories” to describe the production of migrant space. The article describes a project based in London where the everyday practice of walking is used to map migrant territories, which are conceptualized as dispersed and overlapping, causing topological deformations to the actual lived space. We interrogate these deformations through focusing on the micro-scale and the everyday, mapping them as “scapes” and “spheres.” Using specific computational techniques, we transform the original walks into an architectural tool for investigating the fluctuations and flows of the contemporary city. In doing so, we approach territories from two distinct angles: from the geopolitical perspective of territories seen as the product of the interplay of politics, power, and space and from the biological perspective of territories seen as the primal need of all animals, including humans, for space and a certain distinction from their environment and from others

    Анализ применимости численных алгоритмов для моделирования процессов в топке котла с циркулирующим кипящим слоем

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    Моделирование различных задач связано с решением систем дифференциальных уравнений с большим числом неизвестных, что приводит к их упрощению и соответственно отражается на качестве расчета. Данная работа направлена на оценку применимости тех или иных математических алгоритмов для получения качественного моделирования процессов в энергетических котлах с циркулирующим кипящим слоемModeling of various tasks related to the solution of systems of differential equations with a large number of unknowns, which leads to their simplification and, accordingly, affect the quality of the calculation. This work aims to assess the applicability of those or other mathematical algorithms to obtain a quantitative simulation of processes in power boilers with circulating fluidized bed

    Performing the Anglo-Scottish Border: Cultural Landscapes, Heritage and Borderland Identities

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    Recent times have seen much reflection on the nature of the Anglo-Scottish border region; its past, present and potential future. Political concerns have rightly absorbed much of the attention, but at the same time important light has been shed on the legacy of cultural engagements and forms of interaction that might be said to perform and produce this border over time and render it particularly distinctive. A soft, internal border, the territory considered in this article is one with an ancient feudal past and a heavily conserved, preserved and, in parts, still militarized present. It is predominantly rural and characterized by large swathes of forestry, agriculture, and moorland, all of which raise issues of aesthetic and environmental, as well as social and economic sustainability. The concern in the case studies presented in this article is how, through the relational and processual perspectives of border studies and cultural landscapes, we might comprehend the over layered and sedimented histories, the nature of identities, heritage and experience of place here. I consider too the ways in which recent forms of creative practice are contributing to a wider investigation of this region and re-conceptualizing the cultural significance of the border

    Quantitative Modeling of Escherichia coli Chemotactic Motion in Environments Varying in Space and Time

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    Escherichia coli chemotactic motion in spatiotemporally varying environments is studied by using a computational model based on a coarse-grained description of the intracellular signaling pathway dynamics. We find that the cell's chemotaxis drift velocity vd is a constant in an exponential attractant concentration gradient [L]∝exp(Gx). vd depends linearly on the exponential gradient G before it saturates when G is larger than a critical value GC. We find that GC is determined by the intracellular adaptation rate kR with a simple scaling law: . The linear dependence of vd on G = d(ln[L])/dx directly demonstrates E. coli's ability in sensing the derivative of the logarithmic attractant concentration. The existence of the limiting gradient GC and its scaling with kR are explained by the underlying intracellular adaptation dynamics and the flagellar motor response characteristics. For individual cells, we find that the overall average run length in an exponential gradient is longer than that in a homogeneous environment, which is caused by the constant kinase activity shift (decrease). The forward runs (up the gradient) are longer than the backward runs, as expected; and depending on the exact gradient, the (shorter) backward runs can be comparable to runs in a spatially homogeneous environment, consistent with previous experiments. In (spatial) ligand gradients that also vary in time, the chemotaxis motion is damped as the frequency ω of the time-varying spatial gradient becomes faster than a critical value ωc, which is controlled by the cell's chemotaxis adaptation rate kR. Finally, our model, with no adjustable parameters, agrees quantitatively with the classical capillary assay experiments where the attractant concentration changes both in space and time. Our model can thus be used to study E. coli chemotaxis behavior in arbitrary spatiotemporally varying environments. Further experiments are suggested to test some of the model predictions

    Spectroscopic Evidence for an Oxazolone Structure in Anionic b-Type Peptide Fragments

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    Infrared spectra of anionic b-type fragments generated by collision induced dissociation (CID) from deprotonated peptides are reported. Spectra of the b2 fragments of deprotonated AlaAlaAla and AlaTyrAla have been recorded over the 800–1800 cm–1 spectral range by multiple-photon dissociation (MPD) spectroscopy using an FTICR mass spectrometer in combination with the free electron laser FELIX. Structural characterization of the b-type fragments is accomplished by comparison with density functional theory calculated spectra at the B3LYP/6-31++G(d,p) level for different isomeric structures. Although diketopiperazine structures represent the energetically lowest isomers, the IR spectra suggest an oxazolone structure for the b2 fragments of both peptides. Deprotonation is shown to occur on the oxazolone α-carbon, which leads to a conjugated structure in which the negative charge is practically delocalized over the entire oxazolone ring, providing enhanced gas-phase stability

    Oligodendrocytes Do Not Export NAA-Derived Aspartate In Vitro.

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    Oligodendroglial cells are known to de-acetylate the N-acetylaspartate (NAA) synthesized and released by neurons and use it for lipid synthesis. However, the role of NAA regarding their intermediary metabolism remains poorly understood. Two hypotheses were proposed regarding the fate of aspartate after being released by de-acetylation: (1) aspartate is metabolized in the mitochondria of oligodendrocyte lineage cells; (2) aspartate is released to the medium. We report here that aspartoacylase mRNA expression increases when primary rat oligodendrocyte progenitor cells (OPCs) differentiate into mature cells in culture. Moreover, characterising metabolic functions of acetyl coenzyme A and aspartate from NAA catabolism in mature oligodendrocyte cultures after 5 days using isotope-labelled glucose after 5-days of differentiation we found evidence of extensive NAA metabolism. Incubation with [1,6-13C]glucose followed by gas chromatography-mass spectrometry and high performance liquid chromatography analyses of cell extracts and media in the presence and absence of NAA established that the acetate moiety produced by hydrolysis of NAA does not enter mitochondrial metabolism in the form of acetyl coenzyme A. We also resolved the controversy concerning the possible release of aspartate to the medium: aspartate is not released to the medium by oligodendrocytes in amounts detectable by our methods. Therefore we propose that: aspartate released from NAA joins the cytosolic aspartate pool rapidly and takes part in the malate-aspartate shuttle, which transports reducing equivalents from glycolysis into the mitochondria for ATP production and enters the tricarboxylic acid cycle at a slow rate.This work was supported by grants from the UK Multiple Sclerosis Society and from Qatar Foundation. The work was further supported by core funding from the Wellcome Trust and MRC to the Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute. The authors acknowledge the excellent technical support in GC-MS and HPLC analysis from Lars Evje (NTNU, Norway).This is the final version of the article. It first appeared from Springer at http://dx.doi.org/10.1007/s11064-016-1985-y

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe
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