178 research outputs found

    Role of Heat Exchange between Water and Atmosphere in Models of Thermal Pollution in Rivers

    Get PDF
    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

    Numerical Modeling of Transport of Thermal Pollution in a River – Case Study

    Get PDF
    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    Structural role of hydrophobic core in proteins-selected examples

    Get PDF
    This paper discusses the sequence/structure relation. The core question concerns the degree to which similar sequences produce similar structures and vice versa. A mechanism by which similar sequences may result in dissimilar structures is proposed, based on the Fuzzy Oil Drop (FOD) model in which structural similarity is estimated by analyzing the protein’s hydrophobic core. We show that local changes in amino acid sequences, in addition to producing local structural alterations at the substitution site, may also change the shape of the hydrophobic core, significantly affecting the overall tertiary conformation of the protein. Our analysis focuses on four sets of proteins: 1) Pair of designer proteins with specially prepared sequences; 2) Pair of natural proteins modified (mutated) to converge to a point of high-level sequence identity while retaining their respective wild-type tertiary folds; 3) Pair of natural proteins with common ancestry but with differing structures and biological profiles shaped by divergent evolution; and 4) Pair of natural proteins of high structural similarity with no sequence similarity and different biological function

    Sequence-to-structure relation in proteins-amyloidogenic proteins with chameleon sequences

    Get PDF
    The existence of polypeptide chain fragments in which identical sequences translate into different secondary folds gives rise to questions concerning the structural variability associated with amyloidogenesis. In this paper the structural contribution of identical sequences to a common hydrophobic core is assessed on the basis of the fuzzy oil drop model. The model compares the observed hydrophobicity density distribution in a protein molecule to its idealized counterpart, where all hydrophilic residues are exposed on the surface while all hydrophobic residues are internalized. The conformational variability of such fragments is thought to be associated with their role: they either participate in the formation of a stable core, or become involved in mediating the protein’s biological function. The fuzzy oil drop model provides clues as to the role of chameleon sequences in prions, seen as potential loci of conformational changes resulting in amyloidogenesis

    Schistosoma mansoni egg-derived thioredoxin and Sm14 drive the development of IL-10 producing regulatory B cells

    Get PDF
    During chronic schistosome infections, a complex regulatory network is induced to regulate the host immune system, in which IL-10-producing regulatory B (Breg) cells play a significant role. Schistosoma mansoni soluble egg antigens (SEA) are bound and internalized by B cells and induce both human and mouse IL-10 producing Breg cells. To identify Breg-inducing proteins in SEA, we fractionated SEA by size exclusion chromatography and found 6 fractions able to induce IL-10 production by B cells (out of 18) in the high, medium and low molecular weight (MW) range. The high MW fractions were rich in heavily glycosylated molecules, including multi-fucosylated proteins. Using SEA glycoproteins purified by affinity chromatography and synthetic glycans coupled to gold nanoparticles, we investigated the role of these glycan structures in inducing IL-10 production by B cells. Then, we performed proteomics analysis on active low MW fractions and identified a number of proteins with putative immunomodulatory properties, notably thioredoxin (SmTrx1) and the fatty acid binding protein Sm14. Subsequent splenic murine B cell stimulations and hock immunizations with recombinant SmTrx1 and Sm14 showed their ability to dose-dependently induce IL-10 production by B cells both in vitro and in vivo. Identification of unique Breg cells-inducing molecules may pave the way to innovative therapeutic strategies for inflammatory and auto-immune diseases.Author summaryWorm parasites, such as schistosomes, are master regulators of the human immune system, manipulating the host response in order to prolong their survival in their host. As a bystander effect, they also reduce immune responses to allergens and/or auto antigens, thus protecting their host against inflammatory and auto-immune diseases. One of the immune cells involved in immune regulation is the IL-10-producing regulatory B (Breg) cells. Schistosome eggs release various molecules that induce the development of Breg cells, but the identity of these molecules is not yet fully known. In this study, the authors aimed to identify some of these molecules. They investigated both the involvement of glycans on high molecular weight schistosomal egg molecules, as well as dissected the role of proteins with a lower molecular weight coming from schistosomal eggs. Using proteomics, they targeted various interesting molecules, which they recombinantly expressed and confirmed the IL-10 inducing capacity in B cells in vitro and in vivo for 2 molecules. This new knowledge may explain the hyporesponsiveness found in chronic schistosome-infected people and may pave the way to new innovative therapies for inflammatory and auto-immune diseases.Bio-organic Synthesi

    A global multinational survey of cefotaxime-resistant coliforms in urban wastewater treatment plants

    Get PDF
    The World Health Organization Global Action Plan recommends integrated surveillance programs as crucial strategies for monitoring antibiotic resistance. Although several national surveillance programs are in place for clinical and veterinary settings, no such schemes exist for monitoring antibiotic-resistant bacteria in the environment. In this transnational study, we developed, validated, and tested a low-cost surveillance and easy to implement approach to evaluate antibiotic resistance in wastewater treatment plants (WWTPs) by targeting cefotaxime-resistant (CTX-R) coliforms as indicators. The rationale for this approach was: i) coliform quantification methods are internationally accepted as indicators of fecal contamination in recreational waters and are therefore routinely applied in analytical labs; ii) CTX-R coliforms are clinically relevant, associated with extended-spectrum β-lactamases (ESBLs), and are rare in pristine environments. We analyzed 57 WWTPs in 22 countries across Europe, Asia, Africa, Australia, and North America. CTX-R coliforms were ubiquitous in raw sewage and their relative abundance varied significantly (<0.1% to 38.3%), being positively correlated (p < 0.001) with regional atmospheric temperatures. Although most WWTPs removed large proportions of CTX-R coliforms, loads over 103 colony-forming units per mL were occasionally observed in final effluents. We demonstrate that CTX-R coliform monitoring is a feasible and affordable approach to assess wastewater antibiotic resistance status

    A global multinational survey of cefotaxime-resistant coliforms in urban wastewater treatment plants

    Get PDF
    The World Health Organization Global Action Plan recommends integrated surveillance programs as crucial strategies for monitoring antibiotic resistance. Although several national surveillance programs are in place for clinical and veterinary settings, no such schemes exist for monitoring antibiotic-resistant bacteria in the environment. In this transnational study, we developed, validated, and tested a low-cost surveillance and easy to implement approach to evaluate antibiotic resistance in wastewater treatment plants (WWTPs) by targeting cefotaxime-resistant (CTX-R) coliforms as indicators. The rationale for this approach was: i) coliform quantification methods are internationally accepted as indicators of fecal contamination in recreational waters and are therefore routinely applied in analytical labs; ii) CTX-R coliforms are clinically relevant, associated with extended-spectrum β-lactamases (ESBLs), and are rare in pristine environments. We analyzed 57 WWTPs in 22 countries across Europe, Asia, Africa, Australia, and North America. CTX-R coliforms were ubiquitous in raw sewage and their relative abundance varied significantly (<0.1% to 38.3%), being positively correlated (p < 0.001) with regional atmospheric temperatures. Although most WWTPs removed large proportions of CTX-R coliforms, loads over 10 colony-forming units per mL were occasionally observed in final effluents. We demonstrate that CTX-R coliform monitoring is a feasible and affordable approach to assess wastewater antibiotic resistance status. [Abstract copyright: Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.
    corecore