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Sample records for fimbrial designer adhesins

  1. Bioaccumulation of heavy metals by fimbrial designer adhesins

    DEFF Research Database (Denmark)

    Schembri, Mark; Kjærgaard, Kristian; Klemm, Per

    1999-01-01

    Naturally occurring adhesins bind to specific molecular targets in a lock-and-key fashion due to the composition of the binding domain of the adhesin. By introduction of random peptide libraries in a suitable surface exposed carrier protein it is possible to create and select designer adhesins wi...

  2. The role of Actinobacillus actinomycetemcomitans fimbrial adhesin on MMP-8 activity in aggressive periodontitis pathogenesis

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    Rini Devijanti Ridwan

    2012-12-01

    Full Text Available Background: Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans is Gram negative and a major bacterial agent associated with aggressive periodontitis in young adult, this bacteria was an important factor in pathogenesis of aggressive periodontitis. A. actinomycetemcomitans possesses fimbriae with an adhesin protein that was the first bacterial molecules to make physical contact with host. Purpose: The objective of this research was to analyzed the influence of A. actinomycetemcomitans fimbrial adhesin protein induction on MMP-8 activity. Methods: The research was an experimental laboratory study, the step in this study were isolation and identification A. actinomycetemcomitans, characterize A. actinomycetemcomitans adhesin and study the role of A. actinomycetemcomitans adhesin in Wistar rats. Results: The result of this research on the role of adhesin in Wistar rats after analysis with Analysis of Variance (ANOVA showed significant differences in the control group with group induction with A. actinomycetemcomitans, A. actinomycetemcomitans plus adhesin and adhesin. MMP-8 activity increased with induction A. actinomycetemcomitans and 24 kDa A. actinomycetemcomitans adhesin. This fimbrial adhesin protein showed that A. actinomycetemcomitans has the ability to adhesion, colonization and invasion for host in aggressive periodontitis pathogenesis. Conclusion: A. actinomycetemcomitans fimbrial adhesin protein induction increasing MMP-8 activity for aggressive periodontitis pathogenesis.Latar belakang: A. actinomycetemcomitans merupakan salah satu bakteri Gram negatif yang terkait dengan periodontitis agresif yang menyerang penderita usia muda dan merupakan faktor penting dalam patogenesis periodontitis agresif. A. actimycetemcomitans mempunyai fimbriae dengan protein adhesin yang merupakan molekul pertama dari bakteri untuk melakukan kontak fisik dengan host. Tujuan: Tujuan penelitian ini adalah menganalisis pengaruh induksi adhesin A

  3. Structures of C-mannosylated anti-adhesives bound to the type 1 fimbrial FimH adhesin

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    Jerome de Ruyck

    2016-05-01

    Full Text Available Selective inhibitors of the type 1 fimbrial adhesin FimH are recognized as attractive alternatives for antibiotic therapies and prophylaxes against Escherichia coli infections such as urinary-tract infections. To construct these inhibitors, the α-d-mannopyranoside of high-mannose N-glycans, recognized with exclusive specificity on glycoprotein receptors by FimH, forms the basal structure. A hydrophobic aglycon is then linked to the mannose by the O1 oxygen inherently present in the α-anomeric configuration. Substitution of this O atom by a carbon introduces a C-glycosidic bond, which may enhance the therapeutic potential of such compounds owing to the inability of enzymes to degrade C-glycosidic bonds. Here, the first crystal structures of the E. coli FimH adhesin in complex with C-glycosidically linked mannopyranosides are presented. These findings explain the role of the spacer in positioning biphenyl ligands for interactions by means of aromatic stacking in the tyrosine gate of FimH and how the normally hydrated C-glycosidic link is tolerated. As these new compounds can bind FimH, it can be assumed that they have the potential to serve as potent new antagonists of FimH, paving the way for the design of a new family of anti-adhesive compounds against urinary-tract infections.

  4. Evolution of Salmonella enterica virulence via point mutations in the fimbrial adhesin.

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    Dagmara I Kisiela

    Full Text Available Whereas the majority of pathogenic Salmonella serovars are capable of infecting many different animal species, typically producing a self-limited gastroenteritis, serovars with narrow host-specificity exhibit increased virulence and their infections frequently result in fatal systemic diseases. In our study, a genetic and functional analysis of the mannose-specific type 1 fimbrial adhesin FimH from a variety of serovars of Salmonella enterica revealed that specific mutant variants of FimH are common in host-adapted (systemically invasive serovars. We have found that while the low-binding shear-dependent phenotype of the adhesin is preserved in broad host-range (usually systemically non-invasive Salmonella, the majority of host-adapted serovars express FimH variants with one of two alternative phenotypes: a significantly increased binding to mannose (as in S. Typhi, S. Paratyphi C, S. Dublin and some isolates of S. Choleraesuis, or complete loss of the mannose-binding activity (as in S. Paratyphi B, S. Choleraesuis and S. Gallinarum. The functional diversification of FimH in host-adapted Salmonella results from recently acquired structural mutations. Many of the mutations are of a convergent nature indicative of strong positive selection. The high-binding phenotype of FimH that leads to increased bacterial adhesiveness to and invasiveness of epithelial cells and macrophages usually precedes acquisition of the non-binding phenotype. Collectively these observations suggest that activation or inactivation of mannose-specific adhesive properties in different systemically invasive serovars of Salmonella reflects their dynamic trajectories of adaptation to a life style in specific hosts. In conclusion, our study demonstrates that point mutations are the target of positive selection and, in addition to horizontal gene transfer and genome degradation events, can contribute to the differential pathoadaptive evolution of Salmonella.

  5. Subcutaneous or oral immunization of mice with Lactococcus lactis expressing F4 fimbrial adhesin FaeG.

    Science.gov (United States)

    Liu, Shujie; Li, Yongming; Xu, Ziwei; Wang, Yicheng

    2013-01-01

    Enterotoxigenic Escherichia coli (ETEC) is one of the most common causes of diarrhea in neonatal and postweaning piglets. Fimbrial adhesion of ETEC has been considered an important colonization factor with antigenicity. To safely and effectively deliver the F4 (K88) fimbrial adhesin FaeG to the immune system, we have previously constructed the secretory expression vector pNZ8112-faeG, and FaeG was produced in cytoplasmic form in Lactococcus lactis. In this work, BALB/c mice were immunized with recombinant L. lactis to further determine the immunogenicity of recombinant FaeG (rFaeG) via the subcutaneous or oral route. Subcutaneous immunization in mice with recombinant L. lactis induced a significant increase in the F4-specific serum IgG titer and the number of antibody-secreting cells (ASCs) in the spleen. Oral immunization of mice with recombinant L. lactis induced mucosal and systemic F4-specific immune responses and increased the number of ASCs in the spleen, mesenteric lymph nodes and Peyer's patches. High-dose (2.8 × 10(11) CFU) recombinant strains and adjuvant cholera toxin B subunit enhanced specific mucosal immune responses. The results suggest the feasibility of delivering rFaeG expressed in L. lactis to the immune system in order to induce an F4-specific immune response.

  6. K88 Fimbrial Adhesin Targeting of Microspheres Containing Gentamicin Made with Albumin Glycated with Lactose

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    Andre-i Sarabia-Sainz

    2015-09-01

    Full Text Available The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88 was investigated. Glycated albumin with lactose (BSA-glucose-β (4-1 galactose was used as the microsphere matrix (MS-Lac and gentamicin included as the transported antibiotic. The proposed target strategy was that exposed galactoses of MS-Lac could be specifically recognized by E. coli K88 adhesins, and the delivery of gentamicin would inhibit bacterial growth. Lactosylated microspheres (MS-Lac1, MS-Lac2 and MS-Lac3 were obtained using a water-in-oil emulsion, containing gentamicin, followed by crosslinking with different concentrations of glutaraldehyde. Electron microscopy displayed spherical particles with a mean size of 10–17 µm. In vitro release of gentamicin from MS-Lac was best fitted to a first order model, and the antibacterial activity of encapsulated and free gentamicin was comparable. MS-Lac treatments were recognized by plant galactose-specific lectins from Ricinus communis and Sophora japonica and by E. coli K88 adhesins. Results indicate MS-Lac1, produced with 4.2 mg/mL of crosslinker, as the best treatment and that lactosylated microsphere are promising platforms to obtain an active, targeted system against E. coli K88 infections.

  7. Molecular design of Mycoplasma hominis Vaa adhesin

    DEFF Research Database (Denmark)

    Boesen, Thomas; Fedosova, Natalya U.; Kjeldgaard, Morten

    2001-01-01

    The variable adherence-associated (Vaa) adhesin of the opportunistic human pathogen Mycoplasma hominis is a surface-exposed, membrane-associated protein involved in the attachment of the bacterium to host cells. The molecular masses of recombinant 1 and 2 cassette forms of the protein determined...

  8. Mutation of Tyr137 of the universal Escherichia coli fimbrial adhesin FimH relaxes the tyrosine gate prior to mannose binding

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    Said Rabbani

    2017-01-01

    Full Text Available The most prevalent diseases manifested by Escherichia coli are acute and recurrent bladder infections and chronic inflammatory bowel diseases such as Crohn's disease. E. coli clinical isolates express the FimH adhesin, which consists of a mannose-specific lectin domain connected via a pilin domain to the tip of type 1 pili. Although the isolated FimH lectin domain has affinities in the nanomolar range for all high-mannosidic glycans, differentiation between these glycans is based on their capacity to form predominantly hydrophobic interactions within the tyrosine gate at the entrance to the binding pocket. In this study, novel crystal structures of tyrosine-gate mutants of FimH, ligand-free or in complex with heptyl α-d-O-mannopyranoside or 4-biphenyl α-d-O-mannopyranoside, are combined with quantum-mechanical calculations and molecular-dynamics simulations. In the Y48A FimH crystal structure, a large increase in the dynamics of the alkyl chain of heptyl α-d-O-mannopyranoside attempts to compensate for the absence of the aromatic ring; however, the highly energetic and stringent mannose-binding pocket of wild-type FimH is largely maintained. The Y137A mutation, on the other hand, is the most detrimental to FimH affinity and specificity: (i in the absence of ligand the FimH C-terminal residue Thr158 intrudes into the mannose-binding pocket and (ii ethylenediaminetetraacetic acid interacts strongly with Glu50, Thr53 and Asn136, in spite of multiple dialysis and purification steps. Upon mutation, pre-ligand-binding relaxation of the backbone dihedral angles at position 137 in the tyrosine gate and their coupling to Tyr48 via the interiorly located Ile52 form the basis of the loss of affinity of the FimH adhesin in the Y137A mutant.

  9. Fimbrial adhesins from extraintestinal Escherichia coli

    DEFF Research Database (Denmark)

    Klemm, Per; Hancock, Viktoria; Schembri, Mark A.

    2010-01-01

    Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment...

  10. Immunogenicity of recombinant Lactobacillus casei-expressing F4 (K88) fimbrial adhesin FaeG in conjunction with a heat-labile enterotoxin A (LTAK63) and heat-labile enterotoxin B (LTB) of enterotoxigenic Escherichia coli as an oral adjuvant in mice.

    Science.gov (United States)

    Yu, M; Qi, R; Chen, C; Yin, J; Ma, S; Shi, W; Wu, Y; Ge, J; Jiang, Y; Tang, L; Xu, Y; Li, Y

    2017-02-01

    The aims of this study were to develop an effective oral vaccine against enterotoxigenic Escherichia coli (ETEC) infection and to design new and more versatile mucosal adjuvants. Genetically engineered Lactobacillus casei strains expressing F4 (K88) fimbrial adhesin FaeG (rLpPG-2-FaeG) and either co-expressing heat-labile enterotoxin A (LTA) subunit with an amino acid mutation associated with reduced virulence (LTAK63) and a heat-labile enterotoxin B (LTB) subunit of E. coli (rLpPG-2-LTAK63-co-LTB) or fused-expressing LTAK63 and LTB (rLpPG-2-LTAK63-fu-LTB) were constructed. The immunogenicity of rLpPG-2-FaeG in conjunction with rLpPG-2-LTAK63-co-LTB or rLpPG-2-LTAK63-fu-LTB as an orally administered mucosal adjuvant in mice was evaluated. Results showed that the levels of FaeG-specific serum IgG and mucosal sIgA, as well as the proliferation of lymphocytes, were significantly higher in mice orally co-administered rLpPG-2-FaeG and rLpPG-2-LTAK63-fu-LTB compared with those administered rLpPG-2-FaeG alone, and were lower than those co-administered rLpPG-2-FaeG and rLpPG-2-LTAK63-co-LTB. Moreover, effective protection was observed after challenge with F4+ ETEC strain CVCC 230 in mice co-administered rLpPG-2-FaeG and rLpPG-2-LTAK63-co-LTB or rLpPG-2-FaeG and rLpPG-2-LTAK63-fu-LTB group compared with those that received rLpPG-2-FaeG alone. rLpPG-2-FaeG showed greater immunogenicity in combination with LTAK63 and LTB as molecular adjuvants. Recombinant Lactobacillus provides a promising platform for the development of vaccines against F4+ ETEC infection. © 2016 The Society for Applied Microbiology.

  11. Fimbrial phase variation

    DEFF Research Database (Denmark)

    Khandige, Surabhi; Møller-Jensen, Jakob

    2016-01-01

    Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question if the fimb......Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question...... if the fimbrial diversity seen at the population level is the product of random stochasticity or a concerted effort based on active communication. Here we discuss the possibility of a mechanism alternative to a stochastic fimbrial phase variation model affecting the dynamics of a heterogeneous population....

  12. Characterization of fimbrial subunits from Bordetella species

    NARCIS (Netherlands)

    Mooi, F.R.; Heide, H.G.J. van der; Avest, A.R. ter; Welinder, K.G.; Livey, I.; Zeijst, B.A.M. van der; Gaastra, W.

    Using antisera raised against serotype 2 and 3 fimbrial subunits from Bordetella pertussis, serologically related polypeptides were detected in Bordetella bronchiseptica, Bordetella parapertussis and Bordetella avium strains. The two B. pertussis fimbrial subunits, and three of the serologically

  13. Characterization of the modular design of the autolysin/adhesin Aaa from Staphylococcus aureus.

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    Hirschhausen, Nina; Schlesier, Tim; Peters, Georg; Heilmann, Christine

    2012-01-01

    Staphylococcus aureus is a frequent cause of serious and life-threatening infections, such as endocarditis, osteomyelitis, pneumonia, and sepsis. Its adherence to various host structures is crucial for the establishment of diseases. Adherence may be mediated by a variety of adhesins, among them the autolysin/adhesins Atl and Aaa. Aaa is composed of three N-terminal repeated sequences homologous to a lysin motif (LysM) that can confer cell wall attachment and a C-terminally located cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domain having bacteriolytic activity in many proteins. Here, we show by surface plasmon resonance that the LysM domain binds to fibrinogen, fibronectin, and vitronectin respresenting a novel adhesive function for this domain. Moreover, we demonstrated that the CHAP domain not only mediates the bacteriolytic activity, but also adherence to fibrinogen, fibronectin, and vitronectin, thus demonstrating for the first time an adhesive function for this domain. Adherence of an S. aureus aaa mutant and the complemented aaa mutant is slightly decreased and increased, respectively, to vitronectin, but not to fibrinogen and fibronectin, which might at least in part result from an increased expression of atl in the aaa mutant. Furthermore, an S. aureus atl mutant that showed enhanced adherence to fibrinogen, fibronectin, and endothelial cells also demonstrated increased aaa expression and production of Aaa. Thus, the redundant functions of Aaa and Atl might at least in part be interchangeable. Lastly, RT-PCR and zymographic analysis revealed that aaa is negatively regulated by the global virulence gene regulators agr and SarA. We identified novel functions for two widely distributed protein domains, LysM and CHAP, i.e. the adherence to the extracellular matrix proteins fibrinogen, fibronectin, and vitronectin. The adhesive properties of Aaa might promote S. aureus colonization of host extracellular matrix and tissue, suggesting a role for

  14. Chimeric FimH adhesin of type 1 fimbriae: a bacterial surface display system for heterologous sequences

    DEFF Research Database (Denmark)

    Pallesen, L; Poulsen, LK; Christiansen, Gunna

    1995-01-01

    of heterologous DNA segments encoding two reporter sequences. In the selected positions such insertions did not significantly alter the function of the FimH protein with regard to surface location and adhesive ability. The system seemed to be quite flexible, since chimeric versions of the FimH adhesin containing...... as many as 56 foreign amino acids were transported to the bacterial surface as components of the fimbrial organelles. Furthermore, the foreign protein segments were recognized by insert-specific antibodies when expressed within chimeric proteins on the surface of the bacteria. The results from...

  15. The Biology of Neisseria Adhesins

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    Miao-Chiu Hung

    2013-07-01

    Full Text Available Members of the genus Neisseria include pathogens causing important human diseases such as meningitis, septicaemia, gonorrhoea and pelvic inflammatory disease syndrome. Neisseriae are found on the exposed epithelia of the upper respiratory tract and the urogenital tract. Colonisation of these exposed epithelia is dependent on a repertoire of diverse bacterial molecules, extending not only from the surface of the bacteria but also found within the outer membrane. During invasive disease, pathogenic Neisseriae also interact with immune effector cells, vascular endothelia and the meninges. Neisseria adhesion involves the interplay of these multiple surface factors and in this review we discuss the structure and function of these important molecules and the nature of the host cell receptors and mechanisms involved in their recognition. We also describe the current status for recently identified Neisseria adhesins. Understanding the biology of Neisseria adhesins has an impact not only on the development of new vaccines but also in revealing fundamental knowledge about human biology.

  16. Yersinia infection tools—characterization of structure and function of adhesins

    Science.gov (United States)

    Mikula, Kornelia M.; Kolodziejczyk, Robert; Goldman, Adrian

    2013-01-01

    Among the seventeen species of the Gram-negative genus Yersinia, three have been shown to be virulent and pathogenic to humans and animals—Y. enterocolitica, Y. pseudotuberculosis, and Y. pestis. In order to be so, they are armoured with various factors that help them adhere to tissues and organelles, cross the cellular barrier and escape the immune system during host invasion. The group of proteins that mediate pathogen–host interactions constitute adhesins. Invasin, Ail, YadA, YadB, YadC, Pla, and pH 6 antigen belong to the most prominent and best-known Yersinia adhesins. They act at different times and stages of infection complementing each other by their ability to bind a variety of host molecules such as collagen, fibronectin, laminin, β1 integrins, and complement regulators. All the proteins are anchored in the bacterial outer membrane (OM), often forming rod-like or fimbrial-like structures that protrude to the extracellular milieu. Structural studies have shown that the anchor region forms a β-barrel composed of 8, 10, or 12 antiparallel β-strands. Depending on the protein, the extracellular part can be composed of several domains belonging to the immunoglobulin fold superfamily, or form a coiled-coil structure with globular head domain at the end, or just constitute several loops connecting individual β-strands in the β-barrel. Those extracellular regions define the activity of each adhesin. This review focuses on the structure and function of these important molecules, and their role in pathogenesis. PMID:23316485

  17. FaaPred: a SVM-based prediction method for fungal adhesins and adhesin-like proteins.

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    Jayashree Ramana

    Full Text Available Adhesion constitutes one of the initial stages of infection in microbial diseases and is mediated by adhesins. Hence, identification and comprehensive knowledge of adhesins and adhesin-like proteins is essential to understand adhesin mediated pathogenesis and how to exploit its therapeutic potential. However, the knowledge about fungal adhesins is rudimentary compared to that of bacterial adhesins. In addition to host cell attachment and mating, the fungal adhesins play a significant role in homotypic and xenotypic aggregation, foraging and biofilm formation. Experimental identification of fungal adhesins is labor- as well as time-intensive. In this work, we present a Support Vector Machine (SVM based method for the prediction of fungal adhesins and adhesin-like proteins. The SVM models were trained with different compositional features, namely, amino acid, dipeptide, multiplet fractions, charge and hydrophobic compositions, as well as PSI-BLAST derived PSSM matrices. The best classifiers are based on compositional properties as well as PSSM and yield an overall accuracy of 86%. The prediction method based on best classifiers is freely accessible as a world wide web based server at http://bioinfo.icgeb.res.in/faap. This work will aid rapid and rational identification of fungal adhesins, expedite the pace of experimental characterization of novel fungal adhesins and enhance our knowledge about role of adhesins in fungal infections.

  18. MULTIFUNCTIONAL ADHESIN PROTEINS AND THEIR DISPLAY IN MICROBIAL CELLS

    DEFF Research Database (Denmark)

    1999-01-01

    Recombinant cells expressing a multifunctional adhesin protein derived from a naturally occurring adhesin, containing a binding domain that is capable of binding to an organic receptor and a binding domain that is capable of binding to a compound to which the naturally occurring adhesin protein...... substantially does not bind. The cells or modified adhesin proteins, optionally in immobilized form, are useful for separating organic and inorganic compounds including toxic or precious metals from an environment....

  19. stg fimbrial operon from S. Typhi STH2370 contributes to association and cell disruption of epithelial and macrophage-like cells.

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    Berrocal, Liliana; Fuentes, Juan A; Trombert, A Nicole; Jofré, Matías R; Villagra, Nicolás A; Valenzuela, Luis M; Mora, Guido C

    2015-07-07

    Salmonella enterica serovar Typhi (S. Typhi) stg operon, encoding a chaperone/usher fimbria (CU), contributes to an increased adherence to human epithelial cells. However, one report suggests that the presence of the Stg fimbria impairs the monocyte--bacteria association, as deduced by the lower level of invasion to macrophage-like cells observed when the stg fimbrial cluster was overexpressed. Nevertheless, since other CU fimbrial structures increase the entry of S. Typhi into macrophages, and considering that transcriptomic analyses revealed that stg operon is indeed expressed in macrophages, we reassessed the role of the stg operon in the interaction between S. Typhi strain STH2370 and human cells, including macrophage-like cells and mononuclear cells directly taken from human peripheral blood. We compared S. Typhi STH2370 WT, a Chilean clinical strain, and the S. Typhi STH2370 Δstg mutant with respect to association and invasion using epithelial and macrophage-like cells. We observed that deletion of stg operon reduced the association and invasion of S. Typhi, in both cellular types. The presence of the cloned stg operon restored the WT phenotype in all the cases. Moreover, we compared Salmonella enterica sv. Typhimurium 14028s (S. Typhimurium, a serovar lacking stg operon) and S. Typhimurium heterologously expressing S. Typhi stg. We found that the latter presents an increased cell disruption of polarized epithelial cells and an increased association in both epithelial and macrophage-like cells. S. Typhi stg operon encodes a functional adhesin that participates in the interaction bacteria-eukaryotic cells, including epithelial cells and macrophages-like cells. The phenotypes associated to stg operon include increased association and consequent invasion in bacteria-eukaryotic cells, and cell disruption.

  20. Ovary and fimbrial stem cells: biology, niche and cancer origins.

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    Ng, Annie; Barker, Nick

    2015-10-01

    The mammalian ovary is covered by a single-layered epithelium that undergoes rupture and remodelling following each ovulation. Although resident stem cells are presumed to be crucial for this cyclic regeneration, their identity and mode of action have been elusive. Surrogate stemness assays and in vivo fate-mapping studies using recently discovered stem cell markers have identified stem cell pools in the ovary and fimbria that ensure epithelial homeostasis. Recent findings provide insights into intrinsic mechanisms and local extrinsic cues that govern the function of ovarian and fimbrial stem cells. These discoveries have advanced our understanding of stem cell biology in the ovary and fimbria, and lay the foundations for evaluating the contribution of resident stem cells to the initiation and progression of human epithelial ovarian cancer.

  1. Sequestration of zinc oxide by fimbrial designer chelators

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Sørensen, Jack K; Schembri, Mark

    2000-01-01

    O. Sequences responsible for ZnO adherence were identified, and distinct binding motifs were characterized. The sequences selected exhibited various degrees of affinity and specificity towards ZnO. Competitive binding experiments revealed that the sequences recognized only the oxide form of Zn. Interestingly......, one of the inserts exhibited significant homology to a specific sequence in a putative zinc-containing helicase, which suggests that searches such as this one may aid in identifying binding motifs in nature. The zinc-binding bacteria might have a use in detoxification of metal-polluted water...

  2. Capsule Shields the Function of Short Bacterial Adhesins

    OpenAIRE

    Schembri, Mark A.; Dalsgaard, Dorte; Klemm, Per

    2004-01-01

    Bacterial surface structures such as capsules and adhesins are generally regarded as important virulence factors. Here we demonstrate that capsules block the function of the self-recognizing protein antigen 43 through physical shielding. The phenomenon is not restricted to Escherichia coli but can occur in other gram-negative bacteria. Likewise, we show that other short adhesins exemplified by the AIDA-I protein are blocked by the presence of a capsule. The results support the notion that cap...

  3. Functional Analysis of the Chaperone-Usher Fimbrial Gene Clusters of Salmonella enterica serovar Typhi.

    Science.gov (United States)

    Dufresne, Karine; Saulnier-Bellemare, Julie; Daigle, France

    2018-01-01

    The human-specific pathogen Salmonella enterica serovar Typhi causes typhoid, a major public health issue in developing countries. Several aspects of its pathogenesis are still poorly understood. S . Typhi possesses 14 fimbrial gene clusters including 12 chaperone-usher fimbriae ( stg, sth, bcf , fim, saf , sef , sta, stb, stc, std, ste , and tcf ). These fimbriae are weakly expressed in laboratory conditions and only a few are actually characterized. In this study, expression of all S . Typhi chaperone-usher fimbriae and their potential roles in pathogenesis such as interaction with host cells, motility, or biofilm formation were assessed. All S . Typhi fimbriae were better expressed in minimal broth. Each system was overexpressed and only the fimbrial gene clusters without pseudogenes demonstrated a putative major subunits of about 17 kDa on SDS-PAGE. Six of these (Fim, Saf, Sta, Stb, Std, and Tcf) also show extracellular structure by electron microscopy. The impact of fimbrial deletion in a wild-type strain or addition of each individual fimbrial system to an S . Typhi afimbrial strain were tested for interactions with host cells, biofilm formation and motility. Several fimbriae modified bacterial interactions with human cells (THP-1 and INT-407) and biofilm formation. However, only Fim fimbriae had a deleterious effect on motility when overexpressed. Overall, chaperone-usher fimbriae seem to be an important part of the balance between the different steps (motility, adhesion, host invasion and persistence) of S . Typhi pathogenesis.

  4. High-throughput sequencing reveals key genes and immune homeostatic pathways activated in myeloid dendritic cells by Porphyromonas gingivalis 381 and its fimbrial mutants.

    Science.gov (United States)

    Arjunan, P; El-Awady, A; Dannebaum, R O; Kunde-Ramamoorthy, G; Cutler, C W

    2016-02-01

    The human microbiome consists of highly diverse microbial communities that colonize our skin and mucosal surfaces, aiding in maintenance of immune homeostasis. The keystone pathogen Porphyromonas gingivalis induces a dysbiosis and disrupts immune homeostasis through as yet unclear mechanisms. The fimbrial adhesins of P. gingivalis facilitate biofilm formation, invasion of and dissemination by blood dendritic cells; hence, fimbriae may be key factors in disruption of immune homeostasis. In this study we employed RNA-sequencing transcriptome profiling to identify differentially expressed genes (DEGs) in human monocyte-derived dendritic cells (MoDCs) in response to in vitro infection/exposure by Pg381 or its isogenic mutant strains that solely express minor-Mfa1 fimbriae (DPG3), major-FimA fimbriae (MFI) or are deficient in both fimbriae (MFB) relative to uninfected control. Our results yielded a total of 479 DEGs that were at least two-fold upregulated and downregulated in MoDCs significantly (P ≤ 0.05) by all four strains and certain DEGs that were strain-specific. Interestingly, the gene ontology biological and functional analysis shows that the upregulated genes in DPG3-induced MoDCs were more significant than other strains and associated with inflammation, immune response, anti-apoptosis, cell proliferation, and other homeostatic functions. Both transcriptome and quantitative polymerase chain reaction results show that DPG3, which solely expresses Mfa1, increased ZNF366, CD209, LOX1, IDO1, IL-10, CCL2, SOCS3, STAT3 and FOXO1 gene expression. In conclusion, we have identified key DC-mediated immune homeostatic pathways that could contribute to dysbiosis in periodontal infection with P. gingivalis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. The fimbrial protein FlfA from Gallibacterium anatis is a virulence factor and vaccine candidate

    DEFF Research Database (Denmark)

    Bager, Ragnhild Jørgensen; Nesta, Barbara; Pors, Susanne Elisabeth

    2013-01-01

    in the natural chicken host. Furthermore, protection against G. anatis 12656-12 could be induced by immunizing chickens with recombinant FlfA. Finally, in vitro expression of FlfA homologs was observed in a genetically diverse set of G. anatis strains, suggesting the potential of FlfA as a serotype-independent...... vaccine candidate This is the first study describing a fimbrial subunit protein of G. anatis with a clear potential as a vaccine antigen....

  6. Interaction of Mycobacterium leprae with human airway epithelial cells: adherence, entry, survival, and identification of potential adhesins by surface proteome analysis.

    Science.gov (United States)

    Silva, Carlos A M; Danelishvili, Lia; McNamara, Michael; Berredo-Pinho, Márcia; Bildfell, Robert; Biet, Franck; Rodrigues, Luciana S; Oliveira, Albanita V; Bermudez, Luiz E; Pessolani, Maria C V

    2013-07-01

    This study examined the in vitro interaction between Mycobacterium leprae, the causative agent of leprosy, and human alveolar and nasal epithelial cells, demonstrating that M. leprae can enter both cell types and that both are capable of sustaining bacterial survival. Moreover, delivery of M. leprae to the nasal septum of mice resulted in macrophage and epithelial cell infection in the lung tissue, sustaining the idea that the airways constitute an important M. leprae entry route into the human body. Since critical aspects in understanding the mechanisms of infection are the identification and characterization of the adhesins involved in pathogen-host cell interaction, the nude mouse-derived M. leprae cell surface-exposed proteome was studied to uncover potentially relevant adhesin candidates. A total of 279 cell surface-exposed proteins were identified based on selective biotinylation, streptavidin-affinity purification, and shotgun mass spectrometry; 11 of those proteins have been previously described as potential adhesins. In vitro assays with the recombinant forms of the histone-like protein (Hlp) and the heparin-binding hemagglutinin (HBHA), considered to be major mycobacterial adhesins, confirmed their capacity to promote bacterial attachment to epithelial cells. Taking our data together, they suggest that the airway epithelium may act as a reservoir and/or portal of entry for M. leprae in humans. Moreover, our report sheds light on the potentially critical adhesins involved in M. leprae-epithelial cell interaction that may be useful in designing more effective tools for leprosy control.

  7. Capsule shields the function of short bacterial adhesins

    DEFF Research Database (Denmark)

    Schembri, Mark; Dalsgaard, D.; Klemm, Per

    2004-01-01

    Bacterial surface structures such as capsules and adhesins are generally regarded as important virulence factors. Here we demonstrate that capsules block the function of the self-recognizing protein antigen 43 through physical shielding. The phenomenon is not restricted to Escherichia coli but can...

  8. Inhibition of Bifidobacterium Cell Wall 51.74 kDa Adhesin Isolated from Infants Feces Towards Adhesion of Enteric Phatogen E. coli on Enterocyte Balb/C Mice

    Directory of Open Access Journals (Sweden)

    I Sukrama

    2012-01-01

    Full Text Available Objectives: To determine 51.74 kDa adhesin of Bifidobacterium sp cell wall isolated from infants feces as an anti adhesion of E. coli on enterocyte mice. Methods: Randomized Posttest-Only Control Group Design was employed to investigate adherence ability of this adhesin towards E.coli adhesion on mice entherocyte. Results: In this research, it was obtained, that the 51.74 kDa adhesin cell wall of Bifidobacterium sp has an ability to inhibit adhesion of E. coli on mice enterocyte. The ability was increased as an increase of adhsein concentration. Conclusions: that can be drawn from this research is the finding of 51.74 kDa adhesin cell wall of Bifidobacterium sp isolated from infants feces that can inhibit adhseion of E. coli on mice enterocyte. Future work that can be carried out are further researches concerning whether these protein can be applied to inhibit adherence of other pathogen bacteria

  9. Efficiency of Direct Microscopy of Stool Samples Using an Antigen-Specific Adhesin Test for Entamoeba Histolytica

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    Arzu İrvem

    2016-10-01

    Full Text Available Background: E. histolytica is among the common causes of acute gastroenteritis. The pathogenic species E. histolytica and the nonpathogenic species E. dispar cannot be morphologically differentiated, although correct identification of these protozoans is important for treatment and public health. In many laboratories, the screening of leukocytes, erythrocytes, amoebic cysts, trophozoites and parasite eggs is performed using Native-Lugol’s iodine for pre-diagnosis. Aims: In this study, we aimed to investigate the frequency of E. histolytica in stool samples collected from 788 patients residing in the Anatolian region of İstanbul who presented with gastrointestinal complaints. We used the information obtained to evaluate the effectiveness of microscopic examinations when used in combination with the E. histolytica adhesin antigen test. Study Design: Retrospective cross-sectional study Methods: Preparations of stool samples stained with Native-Lugol’s iodine were evaluated using the E. histolytica adhesin test and examined using standard light microscopy at ×40 magnification. Pearson’s Chi-square and Fisher’s exact tests were used for statistical analysis. Logistic regression analysis was used for multivariate analysis. Results: Of 788 samples, 38 (4.8% were positive for E. histolytica adhesin antigens. When evaluated together with the presences of erythrocytes, leukocytes, cysts, and trophozoites, respectively, using logistic regression analysis, leukocyte positivity was significantly higher. The odds ratio of leukocyte positivity increased adhesin test-positivity by 2,530-fold (95% CI=1.01–6.330. Adhesin test-positivity was significant (p=0.047. Conclusion: In line with these findings, the consistency between the presence of cysts and erythrocytes and adhesin test-positivity was found to be highly significant, but that of higher levels of leukocytes was found to be discordant. It was concluded that leukocytes and trophozoites were

  10. F4+ enterotoxigenic Escherichia coli (ETEC) adhesion mediated by the major fimbrial subunit FaeG.

    Science.gov (United States)

    Xia, Pengpeng; Song, Yujie; Zou, Yajie; Yang, Ying; Zhu, Guoqiang

    2015-09-01

    The FaeG subunit is the major constituent of F4(+) fimbriae, associated with glycoprotein and/or glycolipid receptor recognition and majorly contributes to the pathogen attachment to the host cells. To investigate the key factor involved in the fimbrial binding of F4(+) Escherichia coli, both the recombinant E. coli SE5000 strains carrying the fae operon gene clusters that express the different types of fimbriae in vitro, named as rF4ab, rF4ac, and rF4ad, respectively, corresponding to the fimbrial types F4ab, F4ac, and F4ad, and the three isogenic in-frame faeG gene deletion mutants were constructed. The adhesion assays and adhesion inhibition assays showed that ΔfaeG mutants had a significant reduction in the binding to porcine brush border as well as the intestinal epithelial cell lines, while the complemented strain ΔfaeG/pfaeG restored the adhesion function. The recombinant bacterial strains rF4ab, rF4ac, and rF4ad have the same binding property as wild-type F4(+) E. coli strains do and improvement in terms of binding to porcine brush border and the intestinal epithelial cells, and the adherence was blocked by the monoclonal antibody anti-F4 fimbriae. These data demonstrate that the fimbrial binding of F4(+) E. coli is directly mediated by the major FaeG subunit. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Genetic exchange of fimbrial alleles exemplifies the adaptive virulence strategy of Porphyromonas gingivalis.

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    Jennifer E Kerr

    Full Text Available Porphyromonas gingivalis is a gram-negative anaerobic bacterium, a member of the human oral microbiome, and a proposed "keystone" pathogen in the development of chronic periodontitis, an inflammatory disease of the gingiva. P. gingivalis is a genetically diverse species, and is able to exchange chromosomal DNA between strains by natural competence and conjugation. In this study, we investigate the role of horizontal DNA transfer as an adaptive process to modify behavior, using the major fimbriae as our model system, due to their critical role in mediating interactions with the host environment. We show that P. gingivalis is able to exchange fimbrial allele types I and IV into four distinct strain backgrounds via natural competence. In all recombinants, we detected a complete exchange of the entire fimA allele, and the rate of exchange varies between the different strain backgrounds. In addition, gene exchange within other regions of the fimbrial genetic locus was identified. To measure the biological implications of these allele swaps we compared three genotypes of fimA in an isogenic background, strain ATCC 33277. We demonstrate that exchange of fimbrial allele type results in profound phenotypic changes, including the quantity of fimbriae elaborated, membrane blebbing, auto-aggregation and other virulence-associated phenotypes. Replacement of the type I allele with either the type III or IV allele resulted in increased invasion of gingival fibroblast cells relative to the isogenic parent strain. While genetic variability is known to impact host-microbiome interactions, this is the first study to quantitatively assess the adaptive effect of exchanging genes within the pan genome cloud. This is significant as it presents a potential mechanism by which opportunistic pathogens may acquire the traits necessary to modify host-microbial interactions.

  12. Genetic exchange of fimbrial alleles exemplifies the adaptive virulence strategy of Porphyromonas gingivalis.

    Science.gov (United States)

    Kerr, Jennifer E; Abramian, Jared R; Dao, Doan-Hieu V; Rigney, Todd W; Fritz, Jamie; Pham, Tan; Gay, Isabel; Parthasarathy, Kavitha; Wang, Bing-yan; Zhang, Wenjian; Tribble, Gena D

    2014-01-01

    Porphyromonas gingivalis is a gram-negative anaerobic bacterium, a member of the human oral microbiome, and a proposed "keystone" pathogen in the development of chronic periodontitis, an inflammatory disease of the gingiva. P. gingivalis is a genetically diverse species, and is able to exchange chromosomal DNA between strains by natural competence and conjugation. In this study, we investigate the role of horizontal DNA transfer as an adaptive process to modify behavior, using the major fimbriae as our model system, due to their critical role in mediating interactions with the host environment. We show that P. gingivalis is able to exchange fimbrial allele types I and IV into four distinct strain backgrounds via natural competence. In all recombinants, we detected a complete exchange of the entire fimA allele, and the rate of exchange varies between the different strain backgrounds. In addition, gene exchange within other regions of the fimbrial genetic locus was identified. To measure the biological implications of these allele swaps we compared three genotypes of fimA in an isogenic background, strain ATCC 33277. We demonstrate that exchange of fimbrial allele type results in profound phenotypic changes, including the quantity of fimbriae elaborated, membrane blebbing, auto-aggregation and other virulence-associated phenotypes. Replacement of the type I allele with either the type III or IV allele resulted in increased invasion of gingival fibroblast cells relative to the isogenic parent strain. While genetic variability is known to impact host-microbiome interactions, this is the first study to quantitatively assess the adaptive effect of exchanging genes within the pan genome cloud. This is significant as it presents a potential mechanism by which opportunistic pathogens may acquire the traits necessary to modify host-microbial interactions.

  13. Molecular mechanism of extreme mechanostability in a pathogen adhesin.

    Science.gov (United States)

    Milles, Lukas F; Schulten, Klaus; Gaub, Hermann E; Bernardi, Rafael C

    2018-03-30

    High resilience to mechanical stress is key when pathogens adhere to their target and initiate infection. Using atomic force microscopy-based single-molecule force spectroscopy, we explored the mechanical stability of the prototypical staphylococcal adhesin SdrG, which targets a short peptide from human fibrinogen β. Steered molecular dynamics simulations revealed, and single-molecule force spectroscopy experiments confirmed, the mechanism by which this complex withstands forces of over 2 nanonewtons, a regime previously associated with the strength of a covalent bond. The target peptide, confined in a screwlike manner in the binding pocket of SdrG, distributes forces mainly toward the peptide backbone through an intricate hydrogen bond network. Thus, these adhesins can attach to their target with exceptionally resilient mechanostability, virtually independent of peptide side chains. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  14. Staphylococcus aureus adherence to Candida albicans hyphae is mediated by the hyphal adhesin Als3p.

    Science.gov (United States)

    Peters, Brian M; Ovchinnikova, Ekaterina S; Krom, Bastiaan P; Schlecht, Lisa Marie; Zhou, Han; Hoyer, Lois L; Busscher, Henk J; van der Mei, Henny C; Jabra-Rizk, Mary Ann; Shirtliff, Mark E

    2012-12-01

    The bacterium Staphylococcus (St.) aureus and the opportunistic fungus Candida albicans are currently among the leading nosocomial pathogens, often co-infecting critically ill patients, with high morbidity and mortality. Previous investigations have demonstrated preferential adherence of St. aureus to C. albicans hyphae during mixed biofilm growth. In this study, we aimed to characterize the mechanism behind this observed interaction. C. albicans adhesin-deficient mutant strains were screened by microscopy to identify the specific receptor on C. albicans hyphae recognized by St. aureus. Furthermore, an immunoassay was developed to validate and quantify staphylococcal binding to fungal biofilms. The findings from these experiments implicated the C. albicans adhesin agglutinin-like sequence 3 (Als3p) in playing a major role in the adherence process. This association was quantitatively established using atomic force microscopy, in which the adhesion force between single cells of the two species was significantly reduced for a C. albicans mutant strain lacking als3. Confocal microscopy further confirmed these observations, as St. aureus overlaid with a purified recombinant Als3 N-terminal domain fragment (rAls3p) exhibited robust binding. Importantly, a strain of Saccharomyces cerevisiae heterologously expressing Als3p was utilized to further confirm this adhesin as a receptor for St. aureus. Although the parental strain does not bind bacteria, expression of Als3p on the cell surface conferred upon the yeast the ability to strongly bind St. aureus. To elucidate the implications of these in vitro findings in a clinically relevant setting, an ex vivo murine model of co-infection was designed using murine tongue explants. Fluorescent microscopic images revealed extensive hyphal penetration of the epithelium typical of C. albicans mucosal infection. Interestingly, St. aureus bacterial cells were only seen within the epithelial tissue when associated with the invasive

  15. Surface adhesins and exopolymers of selected foodborne pathogens

    DEFF Research Database (Denmark)

    Jaglic, Zoran; Desvaux, Mickaël; Weiss, Agnes

    2014-01-01

    The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalisation, avoidance of an immune response and survival and persistence in the environment. A variety of bacter......The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalisation, avoidance of an immune response and survival and persistence in the environment. A variety...... of bacterial surface structures are involved in this process and these promote bacterial adhesion in a more or less specific manner. In this review, we will focus on those surface adhesins and exopolymers in selected foodborne pathogens that are involved mainly in primary adhesion. Their role in biofilm...

  16. Regions important for the adhesin activity of Moraxella catarrhalis Hag

    Directory of Open Access Journals (Sweden)

    Lafontaine Eric R

    2007-07-01

    Full Text Available Abstract Background The Moraxella catarrhalis Hag protein, an Oca autotransporter adhesin, has previously been shown to be important for adherence of this respiratory tract pathogen to human middle ear and A549 lung cells. Results The present study demonstrates that adherence of M. catarrhalis isogenic hag mutant strains to the human epithelial cell lines Chang (conjunctival and NCIH292 (lung is reduced by 50–93%. Furthermore, expressing Hag in a heterologous Escherichia coli background substantially increased the adherence of recombinant bacteria to NCIH292 cells and murine type IV collagen. Hag did not, however, increase the attachment of E. coli to Chang cells. These results indicate that Hag directly mediates adherence to NCIH292 lung cells and collagen, but is not sufficient to confer binding to conjunctival monolayers. Several in-frame deletions were engineered within the hag gene of M. catarrhalis strain O35E and the resulting proteins were tested for their ability to mediate binding to NCIH292 monolayers, middle ear cells, and type IV collagen. These experiments revealed that epithelial cell and collagen binding properties are separable, and that residues 385–705 of this ~2,000 amino acid protein are important for adherence to middle ear and NCIH292 cells. The region of O35E-Hag encompassing aa 706 to 1194 was also found to be required for adherence to collagen. In contrast, β-roll repeats present in Hag, which are structural features conserved in several Oca adhesins and responsible for the adhesive properties of Yersinia enterocolitica YadA, are not important for Hag-mediated adherence. Conclusion Hag is a major adherence factor for human cells derived from various anatomical sites relevant to pathogenesis by M. catarrhalis and its structure-function relationships differ from those of other, closely-related autotransporter proteins.

  17. Helicobacter pylori SabA Adhesin in Persistent Infection and Chronic Inflammation

    OpenAIRE

    Mahdavi, Jafar; Sondén, Berit; Hurtig, Marina; Olfat, Farzad O.; Forsberg, Lina; Roche, Niamh; Ångström, Jonas; Larsson, Thomas; Teneberg, Susann; Karlsson, Karl-Anders; Altraja, Siiri; Wadström, Torkel; Kersulyte, Dangeruta; Berg, Douglas E.; Dubois, Andre

    2002-01-01

    Helicobacter pylori adherence in the human gastric mucosa involves specific bacterial adhesins and cognate host receptors. Here, we identify sialyl-dimeric-Lewis x glycosphingolipid as a receptor for H. pylori and show that H. pylori infection induced formation of sialyl-Lewis x antigens in gastric epithelium in humans and in a Rhesus monkey. The corresponding sialic acid-binding adhesin (SabA) was isolated with the "retagging" method, and the underlying sabA gene (JHP662/HP0725) wa...

  18. Constraints on lateral gene transfer in promoting fimbrial usher protein diversity and function.

    Science.gov (United States)

    Stubenrauch, Christopher J; Dougan, Gordon; Lithgow, Trevor; Heinz, Eva

    2017-11-01

    Fimbriae are long, adhesive structures widespread throughout members of the family Enterobacteriaceae. They are multimeric extrusions, which are moved out of the bacterial cell through an integral outer membrane protein called usher. The complex folding mechanics of the usher protein were recently revealed to be catalysed by the membrane-embedded translocation and assembly module (TAM). Here, we examine the diversity of usher proteins across a wide range of extraintestinal (ExPEC) and enteropathogenic (EPEC) Escherichia coli , and further focus on a so far undescribed chaperone-usher system, with this usher referred to as UshC. The fimbrial system containing UshC is distributed across a discrete set of EPEC types, including model strains like E2348/67, as well as ExPEC ST131, currently the most prominent multi-drug-resistant uropathogenic E. coli strain worldwide. Deletion of the TAM from a naive strain of E. coli results in a drastic time delay in folding of UshC, which can be observed for a protein from EPEC as well as for two introduced proteins from related organisms, Yersinia and Enterobacter We suggest that this models why the TAM machinery is essential for efficient folding of proteins acquired via lateral gene transfer. © 2017 The Authors.

  19. Description of a Novel Adhesin of Mycobacterium avium Subsp. paratuberculosis

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    Mariana Noelia Viale

    2014-01-01

    Full Text Available The binding and ingestion of Mycobacterium avium subsp. paratuberculosis (MAP by host cells are fibronectin (FN dependent. In several species of mycobacteria, a specific family of proteins allows the attachment and internalization of these bacteria by epithelial cells through interaction with FN. Thus, the identification of adhesion molecules is essential to understand the pathogenesis of MAP. The aim of this study was to identify and characterize FN binding cell wall proteins of MAP. We searched for conserved adhesins within a large panel of surface immunogenic proteins of MAP and investigated a possible interaction with FN. For this purpose, a cell wall protein fraction was obtained and resolved by 2D electrophoresis. The immunoreactive spots were identified by MALDI-TOF MS and a homology search was performed. We selected elongation factor Tu (EF-Tu as candidate for further studies. We demonstrated the FN-binding capability of EF-Tu using a ligand blot assay and also confirmed the interaction with FN in a dose-dependent manner by ELISA. The dissociation constant of EF-Tu was determined by surface plasmon resonance and displayed values within the μM range. These data support the hypothesis that this protein could be involved in the interaction of MAP with epithelial cells through FN binding.

  20. Identification of Burkholderia mallei and Burkholderia pseudomallei adhesins for human respiratory epithelial cells

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    Hogan Robert J

    2010-09-01

    Full Text Available Abstract Background Burkholderia pseudomallei and Burkholderia mallei cause the diseases melioidosis and glanders, respectively. A well-studied aspect of pathogenesis by these closely-related bacteria is their ability to invade and multiply within eukaryotic cells. In contrast, the means by which B. pseudomallei and B. mallei adhere to cells are poorly defined. The purpose of this study was to identify adherence factors expressed by these organisms. Results Comparative sequence analyses identified a gene product in the published genome of B. mallei strain ATCC23344 (locus # BMAA0649 that resembles the well-characterized Yersinia enterocolitica autotransporter adhesin YadA. The gene encoding this B. mallei protein, designated boaA, was expressed in Escherichia coli and shown to significantly increase adherence to human epithelial cell lines, specifically HEp2 (laryngeal cells and A549 (type II pneumocytes, as well as to cultures of normal human bronchial epithelium (NHBE. Consistent with these findings, disruption of the boaA gene in B. mallei ATCC23344 reduced adherence to all three cell types by ~50%. The genomes of the B. pseudomallei strains K96243 and DD503 were also found to contain boaA and inactivation of the gene in DD503 considerably decreased binding to monolayers of HEp2 and A549 cells and to NHBE cultures. A second YadA-like gene product highly similar to BoaA (65% identity was identified in the published genomic sequence of B. pseudomallei strain K96243 (locus # BPSL1705. The gene specifying this protein, termed boaB, appears to be B. pseudomallei-specific. Quantitative attachment assays demonstrated that recombinant E. coli expressing BoaB displayed greater binding to A549 pneumocytes, HEp2 cells and NHBE cultures. Moreover, a boaB mutant of B. pseudomallei DD503 showed decreased adherence to these respiratory cells. Additionally, a B. pseudomallei strain lacking expression of both boaA and boaB was impaired in its ability to

  1. Identification of novel adhesins of M. tuberculosis H37Rv using integrated approach of multiple computational algorithms and experimental analysis.

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    Sanjiv Kumar

    Full Text Available Pathogenic bacteria interacting with eukaryotic host express adhesins on their surface. These adhesins aid in bacterial attachment to the host cell receptors during colonization. A few adhesins such as Heparin binding hemagglutinin adhesin (HBHA, Apa, Malate Synthase of M. tuberculosis have been identified using specific experimental interaction models based on the biological knowledge of the pathogen. In the present work, we carried out computational screening for adhesins of M. tuberculosis. We used an integrated computational approach using SPAAN for predicting adhesins, PSORTb, SubLoc and LocTree for extracellular localization, and BLAST for verifying non-similarity to human proteins. These steps are among the first of reverse vaccinology. Multiple claims and attacks from different algorithms were processed through argumentative approach. Additional filtration criteria included selection for proteins with low molecular weights and absence of literature reports. We examined binding potential of the selected proteins using an image based ELISA. The protein Rv2599 (membrane protein binds to human fibronectin, laminin and collagen. Rv3717 (N-acetylmuramoyl-L-alanine amidase and Rv0309 (L,D-transpeptidase bind to fibronectin and laminin. We report Rv2599 (membrane protein, Rv0309 and Rv3717 as novel adhesins of M. tuberculosis H37Rv. Our results expand the number of known adhesins of M. tuberculosis and suggest their regulated expression in different stages.

  2. FimH adhesin of Escherichia coli K1 type 1 fimbriae activates BV-2 microglia

    International Nuclear Information System (INIS)

    Lee, Jongseok; Shin, Sooan; Teng, C.-H.; Hong, Suk Jin; Kim, Kwang Sik

    2005-01-01

    The generation of intense inflammation in the subarachnoid space in response to meningitis-causing bacteria contributes to brain dysfunction and neuronal injury in bacterial meningitis. Microglia, the major immune effector cells in the central nervous system (CNS), become activated by bacterial components to produce proinflammatory immune mediators. In this study, we showed that FimH adhesin, a tip component of type 1 fimbriae of meningitis-causing Escherichia coli K1, activated the murine microglial cell line, BV-2, which resulted in the production of nitric oxide and the release of tumor necrosis factor-α. Mitogen-activated protein kinases, ERK and p-38, and nuclear factor-κB were involved in FimH adhesin-mediated microglial activation. These findings suggest that FimH adhesin contributes to the CNS inflammatory response by virtue of activating microglia in E. coli meningitis

  3. The influence of adhesin protein from Aggregatibacter actinomycetemcomitans on IL-8 and MMP-8 titre in aggressive periodontitis

    Directory of Open Access Journals (Sweden)

    Rini Revijanti Ridwan

    2015-03-01

    Full Text Available Background: Adhesion can actually be considered as a part of both a powerful survival mechanism and a virulence mechanism for bacterial pathogens. Bacterial adhesin is an instrument for bacteria to do invasion to host. Bacterial adhesin depends on ligand interaction as a signaling mediator that will influence invasion and increase pro and anti-inflammatory because of the influence of the receptors of innate immune response. Aggregatibacter actimycetemcomitans has fimbriae included in type IV pili containing mostly with protein weighed 6.5 kDa and at least with protein weighed 54 kDa. Purpose: The purpose of this research is to analyze the influence of the induction of adhesin protein derived from A. actinomycetemcomitans on IL-8 and MMP-8 titre of Wistar rats. Methods: Adhesin protein derived from A. actinomycetemcomitans weighed 24 kDa was induced on the maxillary first molar sulcus of Wistar rats to prove that adhesin protein could affect IL-8 and MMP-8 titre. Next, to determine its influence, Elisa technique was conducted. Results: It is known that the levels of IL-8 and MMP-8 titre were increased in the group induced with adhesin protein derived from A. actinomycetemcomitans compared with the control group. Conclusion: It can be concluded that adhesin protein derived from A. actinomycetemcomitans can cause alveolar bone damage through the increasing levels of IL-8 and MMP-8 in aggressive periodontitis.

  4. Antibiotic Resistance Determinant-Focused Acinetobacter baumannii Vaccine Designed Using Reverse Vaccinology.

    Science.gov (United States)

    Ni, Zhaohui; Chen, Yan; Ong, Edison; He, Yongqun

    2017-02-21

    As one of the most influential and troublesome human pathogens, Acinetobacter baumannii ( A. baumannii ) has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices. These 35 antigens include 11 TonB dependent receptors, 8 porins, 7 efflux pump proteins, and 2 fimbrial proteins (FilF and CAM87009.1). CAM86003.1 was predicted to be an adhesin outer membrane protein absent from 3 antibiotic-sensitive strains and conserved in 21 antibiotic-resistant strains. Feasible anti-resistance vaccine candidates also include one extracellular protein (QnrA), 3 RND type outer membrane efflux pump proteins, and 3 CTX-M type β-lactamases. Among 39 β-lactamases, A. baumannii CTX-M-2, -5, and -43 enzymes are predicted as adhesins and better vaccine candidates than other β-lactamases to induce preventive immunity and enhance antibiotic treatments. This report represents the first reverse vaccinology study to systematically predict vaccine antigen candidates against antibiotic resistance for a microbial pathogen.

  5. Structural Basis for Sialoglycan Binding by the Streptococcus sanguinis SrpA Adhesin*♦

    Science.gov (United States)

    Bensing, Barbara A.; Loukachevitch, Lioudmila V.; McCulloch, Kathryn M.; Yu, Hai; Vann, Kendra R.; Wawrzak, Zdzislaw; Anderson, Spencer; Chen, Xi; Sullam, Paul M.; Iverson, T. M.

    2016-01-01

    Streptococcus sanguinis is a leading cause of infective endocarditis, a life-threatening infection of the cardiovascular system. An important interaction in the pathogenesis of infective endocarditis is attachment of the organisms to host platelets. S. sanguinis expresses a serine-rich repeat adhesin, SrpA, similar in sequence to platelet-binding adhesins associated with increased virulence in this disease. In this study, we determined the first crystal structure of the putative binding region of SrpA (SrpABR) both unliganded and in complex with a synthetic disaccharide ligand at 1.8 and 2.0 Å resolution, respectively. We identified a conserved Thr-Arg motif that orients the sialic acid moiety and is required for binding to platelet monolayers. Furthermore, we propose that sequence insertions in closely related family members contribute to the modulation of structural and functional properties, including the quaternary structure, the tertiary structure, and the ligand-binding site. PMID:26833566

  6. Functional Characterization of a Mucus-Specific LPXTG Surface Adhesin from Probiotic Lactobacillus rhamnosus GG ▿

    Science.gov (United States)

    von Ossowski, Ingemar; Satokari, Reetta; Reunanen, Justus; Lebeer, Sarah; De Keersmaecker, Sigrid C. J.; Vanderleyden, Jos; de Vos, Willem M.; Palva, Airi

    2011-01-01

    In spite of the wealth of clinical evidence supporting the health benefits of Lactobacillus rhamnosus GG in humans, there is still a lack of understanding of the molecular mechanisms behind its probiosis. Current knowledge suggests that the health-promoting effects of this probiotic strain might be partly dependent on its persistence in the intestine and adhesion to mucosal surfaces. Moreover, L. rhamnosus GG contains mucus-binding pili that might also explain the occupation of its ecological niche as a comparatively less stringent allochthonous intestine-dwelling bacterium. To uncover additional surface proteins involved in mucosal adhesion, we investigated the adherence properties of the only predicted protein (LGG_02337) in L. rhamnosus GG that exhibits homology with a known mucus-binding domain. We cloned a recombinant form of the gene for this putative mucus adhesin and established that the purified protein readily adheres to human intestinal mucus. We also showed that this mucus adhesin is visibly distributed throughout the cell surface and participates in the adhesive interaction between L. rhamnosus GG and mucus, although less prominently than the mucus-binding pili in this strain. Based on primary structural comparisons, we concluded that the current annotation of the LGG_02337 protein likely does not accurately reflect its predicted properties, and we propose that this mucus-specific adhesin be called the mucus-binding factor (MBF). Finally, we interpret our results to mean that L. rhamnosus GG MBF, as an active mucus-specific surface adhesin with a presumed ancillary involvement in pilus-mediated mucosal adhesion, plays a part in the adherent mechanisms during intestinal colonization by this probiotic. PMID:21602388

  7. Heterologous expression in Tritrichomonas foetus of functional Trichomonas vaginalis AP65 adhesin

    Directory of Open Access Journals (Sweden)

    Alderete JF

    2005-03-01

    Full Text Available Abstract Background Trichomonosis, caused by Trichomonas vaginalis, is the number one, nonviral sexually transmitted infection that has adverse consequences for the health of women and children. The interaction of T. vaginalis with vaginal epithelial cells (VECs, a step preparatory to infection, is mediated in part by the prominent surface protein AP65. The bovine trichomonad, Tritrichomonas foetus, adheres poorly to human VECs. Thus, we established a transfection system for heterologous expression of the T. vaginalis AP65 in T. foetus, as an alternative approach to confirm adhesin function for this virulence factor. Results In this study, we show stable transfection and expression of the T. vaginalis ap65 gene in T. foetus from an episomal pBS-ap65-neo plasmid. Expression of the gene and protein was confirmed by RT-PCR and immunoblots, respectively. AP65 in transformed T. foetus bound to host cells. Specific mAbs revealed episomally-expressed AP65 targeted to the parasite surface and hydrogenosome organelles. Importantly, surface-expression of AP65 in T. foetus paralleled increased levels of adherence of transfected bovine trichomonads to human VECs. Conclusion The T. vaginalis AP65 adhesin was stably expressed in T. foetus, and the data obtained using this heterologous system strongly supports the role of AP65 as a prominent adhesin for T. vaginalis. In addition, the heterologous expression in T. foetus of a T. vaginalis gene offers an important, new approach for confirming and characterizing virulence factors.

  8. Primary structure and subcellular localization of two fimbrial subunit-like proteins involved in the biosynthesis of K99 fibrillae.

    Science.gov (United States)

    Roosendaal, E; Jacobs, A A; Rathman, P; Sondermeyer, C; Stegehuis, F; Oudega, B; de Graaf, F K

    1987-09-01

    Analysis of the nucleotide sequence of the distal part of the fan gene cluster encoding the proteins involved in the biosynthesis of the fibrillar adhesin, K99, revealed the presence of two structural genes, fanG and fanH. The amino acid sequence of the gene products (FanG and FanH) showed significant homology to the amino acid sequence of the fibrillar subunit protein (FanC). Introduction of a site-specific frameshift mutation in fanG or fanH resulted in a simultaneous decrease in fibrillae production and adhesive capacity. Analysis of subcellular fractions showed that, in contrast to the K99 fibrillar subunit (FanC), both the FanH and the FanG protein were loosely associated with the outer membrane, possibly on the periplasmic side, but were not components of the fimbriae themselves.

  9. Unraveling the sequence of cytosolic reactions in the export of GspB adhesin from Streptococcus gordonii.

    Science.gov (United States)

    Chen, Yu; Bensing, Barbara A; Seepersaud, Ravin; Mi, Wei; Liao, Maofu; Jeffrey, Philip D; Shajahan, Asif; Sonon, Roberto N; Azadi, Parastoo; Sullam, Paul M; Rapoport, Tom A

    2018-04-06

    Many pathogenic bacteria, including Streptococcus gordonii , possess a pathway for the cellular export of a single serine-rich-repeat protein that mediates the adhesion of bacteria to host cells and the extracellular matrix. This adhesin protein is O -glycosylated by several cytosolic glycosyltransferases and requires three accessory Sec proteins (Asp1-3) for export, but how the adhesin protein is processed for export is not well understood. Here, we report that the S. gordonii adhesin GspB is sequentially O -glycosylated by three enzymes (GtfA/B, Nss, and Gly) that attach N -acetylglucosamine and glucose to Ser/Thr residues. We also found that modified GspB is transferred from the last glycosyltransferase to the Asp1/2/3 complex. Crystal structures revealed that both Asp1 and Asp3 are related to carbohydrate-binding proteins, suggesting that they interact with carbohydrates and bind glycosylated adhesin, a notion that was supported by further analyses. We further observed that Asp1 also has an affinity for phospholipids, which is attenuated by Asp2. In summary, our findings support a model in which the GspB adhesin is sequentially glycosylated by GtfA/B, Nss, and Gly and then transferred to the Asp1/2/3 complex in which Asp1 mediates the interaction of the Asp1/2/3 complex with the lipid bilayer for targeting of matured GspB to the export machinery.

  10. Crystallization and preliminary X-ray data of the FadA adhesin from Fusobacterium nucleatum

    Energy Technology Data Exchange (ETDEWEB)

    Nithianantham, Stanley [Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4935 (United States); Xu, Minghua [Department of Biological Sciences, School of Dentistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4905 (United States); Wu, Nan [Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4935 (United States); Han, Yiping W., E-mail: ywh2@case.edu [Department of Biological Sciences, School of Dentistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4905 (United States); Department of Pathology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Shoham, Menachem, E-mail: ywh2@case.edu [Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4935 (United States)

    2006-12-01

    The FadA adhesin from F. nucleatum, which is involved in bacterial attachment and invasion of human oral epithelial cells, has been crystallized in space group P6{sub 1} or P6{sub 5}, and X-ray data have been collected to 1.9 Å resolution. Fusobacterium nucleatum is a Gram-negative anaerobe prevalent in the oral cavity that is associated with periodontal disease, preterm birth and infections in other parts of the human body. The bacteria attach to and invade epithelial and endothelial cells in the gum tissue and elsewhere via a 13.7 kDa adhesin protein FadA (Fusobacterium adhesin A). FadA exists in two forms: the intact form (pre-FadA), consisting of 129 amino acids, and the mature form (mFadA), which lacks an 18-residue signal sequence. Both forms have been expressed in Escherichia coli and purified. mFadA has been crystallized. The crystals belong to the hexagonal space group P6{sub 1} or P6{sub 5}, with unit-cell parameters a = b = 59.3, c = 125.7 Å and one molecule per asymmetric unit. The crystals exhibit an unusually high solvent content of 74%. Synchrotron X-ray data have been collected to 1.9 Å. The crystals are suitable for X-ray structure determination. The crystal structure of FadA may provide a basis for the development of therapeutic agents to combat periodontal disease and other infections associated with F. nucleatum.

  11. Crystallization and preliminary X-ray data of the FadA adhesin from Fusobacterium nucleatum

    International Nuclear Information System (INIS)

    Nithianantham, Stanley; Xu, Minghua; Wu, Nan; Han, Yiping W.; Shoham, Menachem

    2006-01-01

    The FadA adhesin from F. nucleatum, which is involved in bacterial attachment and invasion of human oral epithelial cells, has been crystallized in space group P6 1 or P6 5 , and X-ray data have been collected to 1.9 Å resolution. Fusobacterium nucleatum is a Gram-negative anaerobe prevalent in the oral cavity that is associated with periodontal disease, preterm birth and infections in other parts of the human body. The bacteria attach to and invade epithelial and endothelial cells in the gum tissue and elsewhere via a 13.7 kDa adhesin protein FadA (Fusobacterium adhesin A). FadA exists in two forms: the intact form (pre-FadA), consisting of 129 amino acids, and the mature form (mFadA), which lacks an 18-residue signal sequence. Both forms have been expressed in Escherichia coli and purified. mFadA has been crystallized. The crystals belong to the hexagonal space group P6 1 or P6 5 , with unit-cell parameters a = b = 59.3, c = 125.7 Å and one molecule per asymmetric unit. The crystals exhibit an unusually high solvent content of 74%. Synchrotron X-ray data have been collected to 1.9 Å. The crystals are suitable for X-ray structure determination. The crystal structure of FadA may provide a basis for the development of therapeutic agents to combat periodontal disease and other infections associated with F. nucleatum

  12. The pvc operon regulates the expression of the Pseudomonas aeruginosa fimbrial chaperone/usher pathway (cup genes.

    Directory of Open Access Journals (Sweden)

    Uzma Qaisar

    Full Text Available The Pseudomonas aeruginosa fimbrial structures encoded by the cup gene clusters (cupB and cupC contribute to its attachment to abiotic surfaces and biofilm formation. The P. aeruginosa pvcABCD gene cluster encodes enzymes that synthesize a novel isonitrile functionalized cumarin, paerucumarin. Paerucumarin has already been characterized chemically, but this is the first report elucidating its role in bacterial biology. We examined the relationship between the pvc operon and the cup gene clusters in the P. aeruginosa strain MPAO1. Mutations within the pvc genes compromised biofilm development and significantly reduced the expression of cupB1-6 and cupC1-3, as well as different genes of the cupB/cupC two-component regulatory systems, roc1/roc2. Adjacent to pvc is the transcriptional regulator ptxR. A ptxR mutation in MPAO1 significantly reduced the expression of the pvc genes, the cupB/cupC genes, and the roc1/roc2 genes. Overexpression of the intact chromosomally-encoded pvc operon by a ptxR plasmid significantly enhanced cupB2, cupC2, rocS1, and rocS2 expression and biofilm development. Exogenously added paerucumarin significantly increased the expression of cupB2, cupC2, rocS1 and rocS2 in the pvcA mutant. Our results suggest that pvc influences P. aeruginosa biofilm development through the cup gene clusters in a pathway that involves paerucumarin, PtxR, and different cup regulators.

  13. Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin-related peptides.

    Science.gov (United States)

    Klueh, U; Bryers, J D; Kreutzer, D L

    2003-10-01

    Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH(3) terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin-related (BRP-A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP-A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP-A was quantified using (125)I-FN, and monoclonal antibodies. (125)I-FN was used to quantitate FN binding to peptide-coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP-A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti-C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti-N terminus antibodies to peptide-bound FN occurred. We believe that the data that indicate an enhanced binding of anti-C antibodies reactive to anti-N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP-A on the polystyrene surface. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 36

  14. Expression of the gene cluster associated with the Escherichia coli pilus adhesin K99.

    OpenAIRE

    Lee, J H; Isaacson, R E

    1995-01-01

    The biogenesis of the pilus adhesin K99 is dependent on the expression of eight contiguous genes, fanA to fanH. Transposon mutants were prepared by using TnlacZ and TnphoA, and selected transposon mutants were used to measure expression of each K99 gene. Expression of the K99 genes is likely controlled at the transcription level, since in general, there were no differences between the results obtained with the two transposons. fanC was the most highly expressed, and fanD was expressed at very...

  15. The Collagen-Binding Adhesin Is a Virulence Factor in Staphylococcus aureus Keratitis

    Science.gov (United States)

    Rhem, Marcus N.; Lech, Elizabeth M.; Patti, Joseph M.; McDevitt, Damien; Höök, Magnus; Jones, Dan B.; Wilhelmus, Kirk R.

    2000-01-01

    A collagen-binding strain of Staphylococcus aureus produced suppurative inflammation in a rabbit model of soft contact lens-associated bacterial keratitis more often than its collagen-binding-negative isogenic mutant. Reintroduction of the cna gene on a multicopy plasmid into the mutant helped it regain its corneal adherence and infectivity. The topical application of a collagen-binding peptide before bacterial challenge decreased S. aureus adherence to deepithelialized corneas. These data suggest that the collagen-binding adhesin is involved in the pathogenesis of S. aureus infection of the cornea. PMID:10816547

  16. Surface contact stimulates the just-in-time deployment of bacterial adhesins.

    Science.gov (United States)

    Li, Guanglai; Brown, Pamela J B; Tang, Jay X; Xu, Jing; Quardokus, Ellen M; Fuqua, Clay; Brun, Yves V

    2012-01-01

    The attachment of bacteria to surfaces provides advantages such as increasing nutrient access and resistance to environmental stress. Attachment begins with a reversible phase, often mediated by surface structures such as flagella and pili, followed by a transition to irreversible attachment, typically mediated by polysaccharides. Here we show that the interplay between pili and flagellum rotation stimulates the rapid transition between reversible and polysaccharide-mediated irreversible attachment. We found that reversible attachment of Caulobacter crescentus cells is mediated by motile cells bearing pili and that their contact with a surface results in the rapid pili-dependent arrest of flagellum rotation and concurrent stimulation of polar holdfast adhesive polysaccharide. Similar stimulation of polar adhesin production by surface contact occurs in Asticcacaulis biprosthecum and Agrobacterium tumefaciens. Therefore, single bacterial cells respond to their initial contact with surfaces by triggering just-in-time adhesin production. This mechanism restricts stable attachment to intimate surface interactions, thereby maximizing surface attachment, discouraging non-productive self-adherence, and preventing curing of the adhesive. © 2011 Blackwell Publishing Ltd.

  17. Structural Basis for Sialoglycan Binding by the Streptococcus sanguinis SrpA Adhesin.

    Science.gov (United States)

    Bensing, Barbara A; Loukachevitch, Lioudmila V; McCulloch, Kathryn M; Yu, Hai; Vann, Kendra R; Wawrzak, Zdzislaw; Anderson, Spencer; Chen, Xi; Sullam, Paul M; Iverson, T M

    2016-04-01

    Streptococcus sanguinisis a leading cause of infective endocarditis, a life-threatening infection of the cardiovascular system. An important interaction in the pathogenesis of infective endocarditis is attachment of the organisms to host platelets.S. sanguinisexpresses a serine-rich repeat adhesin, SrpA, similar in sequence to platelet-binding adhesins associated with increased virulence in this disease. In this study, we determined the first crystal structure of the putative binding region of SrpA (SrpABR) both unliganded and in complex with a synthetic disaccharide ligand at 1.8 and 2.0 Å resolution, respectively. We identified a conserved Thr-Arg motif that orients the sialic acid moiety and is required for binding to platelet monolayers. Furthermore, we propose that sequence insertions in closely related family members contribute to the modulation of structural and functional properties, including the quaternary structure, the tertiary structure, and the ligand-binding site. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Up-regulation of serotonergic binding sites labeled by (3H) WB4101 following fimbrial transection and 5,7-dihydroxytryptamine-induced lesions

    International Nuclear Information System (INIS)

    Morrow, A.L.; Norman, A.B.; Battaglia, G.; Loy, R.; Creese, I.

    1985-01-01

    Lesions of the serotonergic afferents to the hippocampus, by fimbrial transection or by 5,7-dihydroxytryptamine treatment, produce an increase in the Bmax of ( 3 H)WB4101 to its nanomolar affinity binding site, with no effect on its picomolar affinity binding site or on ( 3 H)prazosin binding. The nanomolar site is serotonergic as the serotonergic agonists, serotonin and 8-hydroxy-dipropylaminotetraline (8-OH-DPAT) have nanomolar affinity for ( 3 H)WB4101 binding when studied in the presence of a prazosin mask (30nM) of the alpha-1 component of ( 3 H)WB4101 binding. The serotonin receptor antagonists metergoline, lysergic acid diethylamide and lisuride also have high nanomolar affinities while ketanserin, yohimbine, prazosin and noradrenergic agonists have affinities in the micromolar range. Fimbrial transection or 5,7-dihydroxytryptamine injections produced 32% and 44% increases in the Bmax of ( 3 H)WB4101 binding in the presence of a prazosin mask. Serotonin competition for ( 3 H)WB4101 binding was identical in control and experimental tissues from each lesion experiment. Although specific binding of ( 3 H)WB4101 was increased, there was no change in the affinities or the percentages of the two binding components for serotonin competition with ( 3 H)WB4101. These data suggest that removal of the serotonergic input to the hippocampus produces an increase in the Bmax of serotonin receptor binding sites labeled by ( 3 H)WB4101. 33 references, 3 figures, 3 tables

  19. Antibodies derived from an enterotoxigenic Escherichia coli (ETEC) adhesin tip MEFA (multiepitope fusion antigen) against adherence of nine ETEC adhesins: CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA.

    Science.gov (United States)

    Nandre, Rahul M; Ruan, Xiaosai; Duan, Qiangde; Sack, David A; Zhang, Weiping

    2016-06-30

    Diarrhea continues to be a leading cause of death in children younger than 5 years in developing countries. Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of children's diarrhea and travelers' diarrhea. ETEC bacteria initiate diarrheal disease by attaching to host receptors at epithelial cells and colonizing in small intestine. Therefore, preventing ETEC attachment has been considered the first line of defense against ETEC diarrhea. However, developing vaccines effectively against ETEC bacterial attachment encounters challenge because ETEC strains produce over 23 immunologically heterogeneous adhesins. In this study, we applied MEFA (multiepitope fusion antigen) approach to integrate epitopes from adhesin tips or adhesive subunits of CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA adhesins and to construct an adhesin tip MEFA peptide. We then examined immunogenicity of this tip MEFA in mouse immunization, and assessed potential application of this tip MEFA for ETEC vaccine development. Data showed that mice intraperitoneally immunized with this adhesin tip MEFA developed IgG antibody responses to all nine ETEC adhesins. Moreover, ETEC and E. coli bacteria expressing these nine adhesins, after incubation with serum of the immunized mice, exhibited significant reduction in attachment to Caco-2 cells. These results indicated that anti-adhesin antibodies induced by this adhesin tip MEFA blocked adherence of the most important ETEC adhesins, suggesting this multivalent tip MEFA may be useful for developing a broadly protective anti-adhesin vaccine against ETEC diarrhea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Nanowire arrays as cell force sensors to investigate adhesin-enhanced holdfast of single cell bacteria and biofilm stability

    NARCIS (Netherlands)

    Sahoo, P.K.; Janissen, R.; Monteiro, M.P.; Cavalli, A.; Murillo, D.M.; Merfa, M.V.; Cesar, C.L.; Carvalho, H.F.; de Souza, A.A.; Bakkers, E.P.A.M.; Cotta, M.A.

    2016-01-01

    Surface attachment of a planktonic bacteria, mediated by adhesins and extracellular polymeric substances (EPS), is a crucial step for biofilm formation. Some pathogens can modulate cell adhesiveness, impacting host colonization and virulence. A framework able to quantify cell-surface interaction

  1. A sialoreceptor binding motif in the Mycoplasma synoviae adhesin VlhA.

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    Meghan May

    Full Text Available Mycoplasma synoviae depends on its adhesin VlhA to mediate cytadherence to sialylated host cell receptors. Allelic variants of VlhA arise through recombination between an assemblage of promoterless vlhA pseudogenes and a single transcription promoter site, creating lineages of M. synoviae that each express a different vlhA allele. The predicted full-length VlhA sequences adjacent to the promoter of nine lineages of M. synoviae varying in avidity of cytadherence were aligned with that of the reference strain MS53 and with a 60-a.a. hemagglutinating VlhA C-terminal fragment from a Tunisian lineage of strain WVU1853(T. Seven different sequence variants of an imperfectly conserved, single-copy, 12-a.a. candidate cytadherence motif were evident amid the flanking variable residues of the 11 total sequences examined. The motif was predicted to adopt a short hairpin structure in a low-complexity region near the C-terminus of VlhA. Biotinylated synthetic oligopeptides representing four selected variants of the 12-a.a. motif, with the whole synthesized 60-a.a. fragment as a positive control, differed (P<0.01 in the extent they bound to chicken erythrocyte membranes. All bound to a greater extent (P<0.01 than scrambled or irrelevant VlhA domain negative control peptides did. Experimentally introduced branched-chain amino acid (BCAA substitutions Val3Ile and Leu7Ile did not significantly alter binding, whereas fold-destabilizing substitutions Thr4Gly and Ala9Gly tended to reduce it (P<0.05. Binding was also reduced to background levels (P<0.01 when the peptides were exposed to desialylated membranes, or were pre-saturated with free sialic acid before exposure to untreated membranes. From this evidence we conclude that the motif P-X-(BCAA-X-F-X-(BCAA-X-A-K-X-G binds sialic acid and likely mediates VlhA-dependent M. synoviae attachment to host cells. This conserved mechanism retains the potential for fine-scale rheostasis in binding avidity, which could be a

  2. [Lectins, adhesins, and lectin-like substances of lactobacilli and bifidobacteria].

    Science.gov (United States)

    Lakhtin, V M; Aleshkin, V A; Lakhtin, M V; Afanas'ev, S S; Pospelova, V V; Shenderov, B A

    2006-01-01

    Cell-surface adhesion factors of lactobacilli and bifidobacteria, such as lectin/adhesin proteins of S-layers, secreted lectin-like bacteriocins, and lectin-like complexes, are considered and classified in the article. Certain general and specific properties of these factors are noted, such as in vitro and in vivo adhesion, cell co(aggregation), participation in the forming of microbial biofilms and colonization of mammalian alimentary tract, as well as complexation with biopolymers and bioeffectors, specificity to glycanes and natural glycoconjugates, domain and spatial organization of adhesion factors, co-functioning with other cytokines (pro- and anti-inflammatory ones), regulation of target cell properties, and other biological and physiological activities. The authors also note possibilities of application of lectins and lectin-like proteins of probiotic strains of lactobacilli and bifidobacteria in medicine and biotechnology.

  3. Identification and characterization of a novel Plasmodium falciparum adhesin involved in erythrocyte invasion.

    Directory of Open Access Journals (Sweden)

    Nidhi Hans

    Full Text Available Malaria remains a major health problem worldwide. All clinical symptoms of malaria are attributed to the asexual blood stages of the parasite life cycle. Proteins resident in apical organelles and present on the surface of P. falciparum merozoites are considered promising candidates for the development of blood stage malaria vaccines. In the present study, we have identified and characterized a microneme associated antigen, PfMA [PlasmoDB Gene ID: PF3D7_0316000, PFC0700c]. The gene was selected by applying a set of screening criteria such as transcriptional upregulation at late schizogony, inter-species conservation and the presence of signal sequence or transmembrane domains. The gene sequence of PfMA was found to be conserved amongst various Plasmodium species. We experimentally demonstrated that the transcript for PfMA was expressed only in the late blood stages of parasite consistent with a putative role in erythrocyte invasion. PfMA was localized by immunofluorescence and immuno-electron microscopy to be in the micronemes, an apical organelle of merozoites. The functional role of the PfMA protein in erythrocyte invasion was identified as a parasite adhesin involved in direct attachment with the target erythrocyte. PfMA was demonstrated to bind erythrocytes in a sialic acid independent, chymotrypsin and trypsin resistant manner and its antibodies inhibited P. falciparum erythrocyte invasion. Invasion of erythrocytes is a complex multistep process that involves a number of redundant ligand-receptor interactions many of which still remain unknown and even uncharacterized. Our work has identified and characterized a novel P. falciparum adhesin involved in erythrocyte invasion.

  4. Defining Potential Vaccine Targets of Haemophilus ducreyi Trimeric Autotransporter Adhesin DsrA.

    Science.gov (United States)

    Fusco, William G; Choudhary, Neelima R; Stewart, Shelley M; Alam, S Munir; Sempowski, Gregory D; Elkins, Christopher; Leduc, Isabelle

    2015-04-01

    Haemophilus ducreyi is the causative agent of the sexually transmitted genital ulcer disease chancroid. Strains of H. ducreyi are grouped in two classes (I and II) based on genotypic and phenotypic differences, including those found in DsrA, an outer membrane protein belonging to the family of multifunctional trimeric autotransporter adhesins. DsrA is a key serum resistance factor of H. ducreyi that prevents binding of natural IgM at the bacterial surface and functions as an adhesin to fibronectin, fibrinogen, vitronectin, and human keratinocytes. Monoclonal antibodies (MAbs) were developed to recombinant DsrA (DsrA(I)) from prototypical class I strain 35000HP to define targets for vaccine and/or therapeutics. Two anti-DsrAI MAbs bound monomers and multimers of DsrA from genital and non-genital/cutaneous H. ducreyi strains in a Western blot and reacted to the surface of the genital strains; however, these MAbs did not recognize denatured or native DsrA from class II strains. In a modified extracellular matrix protein binding assay using viable H. ducreyi, one of the MAbs partially inhibited binding of fibronectin, fibrinogen, and vitronectin to class I H. ducreyi strain 35000HP, suggesting a role for anti-DsrA antibodies in preventing binding of H. ducreyi to extracellular matrix proteins. Standard ELISA and surface plasmon resonance using a peptide library representing full-length, mature DsrAI revealed the smallest nominal epitope bound by one of the MAbs to be MEQNTHNINKLS. Taken together, our findings suggest that this epitope is a potential target for an H. ducreyi vaccine.

  5. Regulation of Expression of Uropathogenic Escherichia coli Nonfimbrial Adhesin TosA by PapB Homolog TosR in Conjunction with H-NS and Lrp

    Science.gov (United States)

    Engstrom, Michael D.

    2016-01-01

    Urinary tract infections (UTIs) are a major burden to human health. The overwhelming majority of UTIs are caused by uropathogenic Escherichia coli (UPEC) strains. Unlike some pathogens, UPEC strains do not have a fixed core set of virulence and fitness factors but do have a variety of adhesins and regulatory pathways. One such UPEC adhesin is the nonfimbrial adhesin TosA, which mediates adherence to the epithelium of the upper urinary tract. The tos operon is AT rich, resides on pathogenicity island aspV, and is not expressed under laboratory conditions. Because of this, we hypothesized that tosA expression is silenced by H-NS. Lrp, based on its prominent function in the regulation of other adhesins, is also hypothesized to contribute to tos operon regulation. Using a variety of in vitro techniques, we mapped both the tos operon promoter and TosR binding sites. We have now identified TosR as a dual regulator of the tos operon, which could control the tos operon in association with H-NS and Lrp. H-NS is a negative regulator of the tos operon, and Lrp positively regulates the tos operon. Exogenous leucine also inhibits Lrp-mediated tos operon positive regulation. In addition, TosR binds to the pap operon, which encodes another important UPEC adhesin, P fimbria. Induction of TosR synthesis reduces production of P fimbria. These studies advance our knowledge of regulation of adhesin expression associated with uropathogen colonization of a host. PMID:26755158

  6. Lactobacillus reuteri Surface Mucus Adhesins Upregulate Inflammatory Responses Through Interactions With Innate C-Type Lectin Receptors.

    Science.gov (United States)

    Bene, Krisztián P; Kavanaugh, Devon W; Leclaire, Charlotte; Gunning, Allan P; MacKenzie, Donald A; Wittmann, Alexandra; Young, Ian D; Kawasaki, Norihito; Rajnavolgyi, Eva; Juge, Nathalie

    2017-01-01

    The vertebrate gut symbiont Lactobacillus reuteri exhibits strain-specific adhesion and health-promoting properties. Here, we investigated the role of the mucus adhesins, CmbA and MUB, upon interaction of L. reuteri ATCC PTA 6475 and ATCC 53608 strains with human monocyte-derived dendritic cells (moDCs). We showed that mucus adhesins increased the capacity of L. reuteri strains to interact with moDCs and promoted phagocytosis. Our data also indicated that mucus adhesins mediate anti- and pro-inflammatory effects by the induction of interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α), IL-1β, IL-6, and IL-12 cytokines. L. reuteri ATCC PTA 6475 and ATCC 53608 were exclusively able to induce moDC-mediated Th1 and Th17 immune responses. We further showed that purified MUB activates moDCs and induces Th1 polarized immune responses associated with increased IFNγ production. MUB appeared to mediate these effects via binding to C-type lectin receptors (CLRs), as shown using cell reporter assays. Blocking moDCs with antibodies against DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) or Dectin-2 did not affect the uptake of the MUB-expressing strain, but reduced the production of TNF-α and IL-6 by moDCs significantly, in line with the Th1 polarizing capacity of moDCs. The direct interaction between MUB and CLRs was further confirmed by atomic force spectroscopy. Taken together these data suggest that mucus adhesins expressed at the cell surface of L. reuteri strains may exert immunoregulatory effects in the gut through modulating the Th1-promoting capacity of DCs upon interaction with C-type lectins.

  7. Rapid evolution of the Helicobacter pylori AlpA adhesin in a high gastric cancer risk region from Colombia

    Directory of Open Access Journals (Sweden)

    Andrés Julián Gutiérrez-Escobar

    2018-05-01

    Full Text Available To be able to survive, Helicobacter pylori must adhere to the gastric epithelial cells of its human host. For this purpose, the bacterium employs an array of adhesins, for example, AlpA. The adhesin AlpA has been proposed as a major adhesin because of its critical role in human stomach colonization. Therefore, understanding how AlpA evolved could be important for the development of new diagnostic strategies. However, the genetic variation and microevolutionary patterns of alpA have not been described in Colombia. The study aim was to describe the variation patterns and microevolutionary process of alpA in Colombian clinical isolates of H. pylori. The existing polymorphisms, which are deviations from the neutral model of molecular evolution, and the genetic differentiation of the alpA gene from Colombian clinical isolates of H. pylori were determined. The analysis shows that gene conversion and purifying selection have shaped the evolution of three different variants of alpA in Colombia.

  8. The Haemophilus ducreyi trimeric autotransporter adhesin DsrA protects against an experimental infection in the swine model of chancroid.

    Science.gov (United States)

    Fusco, William G; Choudhary, Neelima R; Routh, Patty A; Ventevogel, Melissa S; Smith, Valerie A; Koch, Gary G; Almond, Glen W; Orndorff, Paul E; Sempowski, Gregory D; Leduc, Isabelle

    2014-06-24

    Adherence of pathogens to cellular targets is required to initiate most infections. Defining strategies that interfere with adhesion is therefore important for the development of preventative measures against infectious diseases. As an adhesin to host extracellular matrix proteins and human keratinocytes, the trimeric autotransporter adhesin DsrA, a proven virulence factor of the Gram-negative bacterium Haemophilus ducreyi, is a potential target for vaccine development. A recombinant form of the N-terminal passenger domain of DsrA from H. ducreyi class I strain 35000HP, termed rNT-DsrAI, was tested as a vaccine immunogen in the experimental swine model of H. ducreyi infection. Viable homologous H. ducreyi was not recovered from any animal receiving four doses of rNT-DsrAI administered with Freund's adjuvant at two-week intervals. Control pigs receiving adjuvant only were all infected. All animals receiving the rNT-DsrAI vaccine developed antibody endpoint titers between 3.5 and 5 logs. All rNT-DsrAI antisera bound the surface of the two H. ducreyi strains used to challenge immunized pigs. Purified anti-rNT-DsrAI IgG partially blocked binding of fibrinogen at the surface of viable H. ducreyi. Overall, immunization with the passenger domain of the trimeric autotransporter adhesin DsrA accelerated clearance of H. ducreyi in experimental lesions, possibly by interfering with fibrinogen binding. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Essential roles and regulation of the Legionella pneumophila collagen-like adhesin during biofilm formation.

    Directory of Open Access Journals (Sweden)

    Julia Mallegol

    Full Text Available Legionellosis is mostly caused by Legionella pneumophila (Lp and is defined by a severe respiratory illness with a case fatality rate ranging from 5 to 80%. In a previous study, we showed that a glycosaminoglycan (GAG-binding adhesin of Lp, named Lcl, is produced during legionellosis and is unique to the L. pneumophila species. Importantly, a mutant depleted in Lcl (Δlpg2644 is impaired in adhesion to GAGs and epithelial cells and in biofilm formation. Here, we examine the molecular function(s of Lcl and the transcriptional regulation of its encoding gene during different stages of the biofilm development. We show that the collagen repeats and the C-terminal domains of Lcl are crucial for the production of biofilm. We present evidence that Lcl is involved in the early step of surface attachment but also in intercellular interactions. Furthermore, we address the relationship between Lcl gene regulation during biofilm formation and quorum sensing (QS. In a static biofilm assay, we show that Lcl is differentially regulated during growth phases and biofilm formation. Moreover, we show that the transcriptional regulation of lpg2644, mediated by a prototype of QS signaling homoserine lactone (3OC12-HSL, may play a role during the biofilm development. Thus, transcriptional down-regulation of lpg2644 may facilitate the dispersion of Lp to reinitiate biofilm colonization on a distal surface.

  10. Apa is a trimeric autotransporter adhesin of Actinobacillus pleuropneumoniae responsible for autoagglutination and host cell adherence.

    Science.gov (United States)

    Xiao, Longwen; Zhou, Liang; Sun, Changjiang; Feng, Xin; Du, ChongTao; Gao, Yu; Ji, Qun; Yang, Shuxin; Wang, Yu; Han, Wenyu; Langford, P R; Lei, Liancheng

    2012-10-01

    Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, and adherence to host cells is a key step in the pathogenic process. Although trimeric autotransporter adhesins (TAAs) were identified in many pathogenic bacteria in recent years, none in A. pleuropneumoniae have been characterized. In this study, we identified a TAA from A. pleuropneumoniae, Apa, and characterized the contribution of its amino acid residues to the adhesion process. Sequence analysis of the C-terminal amino acid residues of Apa revealed the presence of a putative translocator domain and six conserved HsfBD1-like or HsfBD2-like binding domains. Western blot analysis revealed that the 126 C-terminal amino acids of Apa could form trimeric molecules. By confocal laser scanning microscopy, one of these six domains (ApaBD3) was determined to mediate adherence to epithelial cells. Adherence assays and adherence inhibition assays using a recombinant E. coli- ApaBD3 strain which expressed ApaBD3 on the surface of E. coli confirmed that this domain was responsible for the adhesion activity. Moreover, cellular enzyme-linked immunosorbent assays demonstrated that ApaBD3 mediated high-level adherence to epithelial cell lines. Intriguingly, autoagglutination was observed with the E. coli- ApaBD3 strain, and this phenomenon was dependent upon the association of the expressed ApaBD3 with the C-terminal translocator domain. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. sae is essential for expression of the staphylococcal adhesins Eap and Emp.

    Science.gov (United States)

    Harraghy, Niamh; Kormanec, Jan; Wolz, Christiane; Homerova, Dagmar; Goerke, Christiane; Ohlsen, Knut; Qazi, Saara; Hill, Philip; Herrmann, Mathias

    2005-06-01

    Eap and Emp are two Staphylococcus aureus adhesins initially described as extracellular matrix binding proteins. Eap has since emerged as being important in adherence to and invasion of eukaryotic cells, as well as being described as an immunomodulator and virulence factor in chronic infections. This paper describes the mapping of the transcription start point of the eap and emp promoters. Moreover, using reporter-gene assays and real-time PCR in defined regulatory mutants, environmental conditions and global regulators affecting expression of eap and emp were investigated. Marked differences were found in expression of eap and emp between strain Newman and the 8325 derivatives SH1000 and 8325-4. Moreover, both genes were repressed in the presence of glucose. Analysis of expression of both genes in various regulatory mutants revealed that sarA and agr were involved in their regulation, but the data suggested that there were additional regulators of both genes. In a sae mutant, expression of both genes was severely repressed. sae expression was also reduced in the presence of glucose, suggesting that repression of eap and emp in glucose-containing medium may, in part, be a consequence of a decrease in expression of sae.

  12. Characterization of cleavage events in the multifunctional cilium adhesin Mhp684 (P146) reveals a mechanism by which Mycoplasma hyopneumoniae regulates surface topography.

    Science.gov (United States)

    Bogema, Daniel R; Deutscher, Ania T; Woolley, Lauren K; Seymour, Lisa M; Raymond, Benjamin B A; Tacchi, Jessica L; Padula, Matthew P; Dixon, Nicholas E; Minion, F Chris; Jenkins, Cheryl; Walker, Mark J; Djordjevic, Steven P

    2012-01-01

    hyopneumoniae infection provide only partial protection. Proteins of the P97/P102 families are highly expressed, functionally redundant molecules that are substrates of endoproteases that generate multifunctional adhesin fragments on the cell surface. We show that P146 displays a chimeric structure consisting of an N terminus, which shares sequence identity with P97, and novel central and C-terminal regions. P146 is endoproteolytically processed at multiple sites, generating at least nine fragments on the surface of M. hyopneumoniae. Dominant cleavage events occurred at S/T-X-F↓X-D/E-like sites generating P50(P146), P40(P146), and P85(P146). Recombinant proteins designed to mimic the major cleavage fragments bind porcine cilia, heparin, and plasminogen. P146 undergoes endoproteolytic processing events at multiple sites and with differential processing efficiency, generating combinatorial diversity on the surface of M. hyopneumoniae.

  13. Expression of the gene cluster associated with the Escherichia coli pilus adhesin K99.

    Science.gov (United States)

    Lee, J H; Isaacson, R E

    1995-10-01

    The biogenesis of the pilus adhesin K99 is dependent on the expression of eight contiguous genes, fanA to fanH. Transposon mutants were prepared by using TnlacZ and TnphoA, and selected transposon mutants were used to measure expression of each K99 gene. Expression of the K99 genes is likely controlled at the transcription level, since in general, there were no differences between the results obtained with the two transposons. fanC was the most highly expressed, and fanD was expressed at very low levels. The expression of TnlacZ fusions in fanA and fanB fusions was high. Deletion of fanA, fanB, and part of fanC abolished the expression of fanD but had no effect on the distal genes fanE to fanH. To locate the DNA regions required for expression of fanE to fanH, deletion mutations were prepared and the effects on expression of fanE to fanH were determined. The deletion of a segment between fanD and fanE abolished fanE and fanF expression but did not affect fanG and fanH. The deletion of a portion of fanF (approximately 1 kb proximal to fanG) abolished the expression of fanG and fanH. These results indicate the presence of regulatory elements proximal to fanE and to fanG. Putative promoters were identified in these regions by DNA homology and by primer extension. A stem-loop structure that may act as a transcriptional attenuator of fanF was also found at the beginning of fanF. These data confirm our previous model of K99 transcriptional organization.

  14. Contribution of the collagen adhesin Acm to pathogenesis of Enterococcus faecium in experimental endocarditis.

    Science.gov (United States)

    Nallapareddy, Sreedhar R; Singh, Kavindra V; Murray, Barbara E

    2008-09-01

    Enterococcus faecium is a multidrug-resistant opportunist causing difficult-to-treat nosocomial infections, including endocarditis, but there are no reports experimentally demonstrating E. faecium virulence determinants. Our previous studies showed that some clinical E. faecium isolates produce a cell wall-anchored collagen adhesin, Acm, and that an isogenic acm deletion mutant of the endocarditis-derived strain TX0082 lost collagen adherence. In this study, we show with a rat endocarditis model that TX0082 Deltaacm::cat is highly attenuated versus wild-type TX0082, both in established (72 h) vegetations (P Acm the first factor shown to be important for E. faecium pathogenesis. In contrast, no mortality differences were observed in a mouse peritonitis model. While 5 of 17 endocarditis isolates were Acm nonproducers and failed to adhere to collagen in vitro, all had an intact, highly conserved acm locus. Highly reduced acm mRNA levels (>or=50-fold reduction relative to an Acm producer) were found in three of these five nonadherent isolates, including the sequenced strain TX0016, by quantitative reverse transcription-PCR, indicating that acm transcription is downregulated in vitro in these isolates. However, examination of TX0016 cells obtained directly from infected rat vegetations by flow cytometry showed that Acm was present on 40% of cells grown during infection. Finally, we demonstrated a significant reduction in E. faecium collagen adherence by affinity-purified anti-Acm antibodies from E. faecium endocarditis patient sera, suggesting that Acm may be a potential immunotarget for strategies to control this emerging pathogen.

  15. The use of quantitative PCR for identification and quantification of Brachyspira pilosicoli, Lawsonia intracellularis and Escherichia coli fimbrial types F4 and F18 in pig feces

    DEFF Research Database (Denmark)

    Ståhl, Marie; Kokotovic, Branko; Hjulsager, Charlotte Kristiane

    2011-01-01

    Four quantitative PCR (qPCR) assays were evaluated for quantitative detection of Brachyspira pilosicoli, Lawsonia intracellularis, and E. coli fimbrial types F4 and F18 in pig feces. Standard curves were based on feces spiked with the respective reference strains. The detection limits from...... the spiking experiments were 102 bacteria/g feces for BpiloqPCR and Laws-qPCR, 103 CFU/g feces for F4-qPCR and F18-qPCR. The PCR efficiency for all four qPCR assays was between 0.91 and 1.01 with R2 above 0.993. Standard curves, slopes and elevation, varied between assays and between measurements from pure...... DNA from reference strains and feces spiked with the respective strains. The linear ranges found for spiked fecal samples differed both from the linear ranges from pure culture of the reference strains and between the qPCR tests. The linear ranges were five log units for F4- qPCR, and Laws-qPCR, six...

  16. The detection of K88, K99 fimbrial antigen and enterotoxin genes of Escherichia coli isolated from piglets and calves with diarrhoea in Indonesia

    Directory of Open Access Journals (Sweden)

    Supar

    1996-03-01

    Full Text Available Enterotoxigenic Escherichia coli (ETEC strains cause diarrhoeal disease in piglets and calves in Indonesia. These strains possess two virulence factors namely attachment and enterotoxin antigens . These factors could be detected phenotypically and genetically. Haemolytic Escherichia coli (E coli isolates possessing K88 fimbrial antigen associated with 0-group 108 and 149. They were positive for K88 gene and demonstrated their ability to produce heat labile enterotoxin (LT and genetically were all positive for LT gene . Seventeen isolates ofE coli K88 which associated with 0-group 149 were positive forSTb gene, other O-serotypes were negative . Ten isolates of Ecoli K88 which associated with 0-group 108 possessed K88, K99, LT and STa genes, but negative for STb gene . However, phenotypically the K99 antigen and STa toxin were not expressed under laboratory conditions, the reason was not well understood . E. coli K99 strains isolated from calves wit h diarrhoea were all associated with 0-group 9 and produced STa toxin when tested by suckling mousse bioassay. The E. coli K99 calf isolates were all hybridized with K99 and STa gene only . It is likely that K99 gene is associated with STa gene . The DNA hybridization technique is more convenience to be used for confirmation diagnosis of colibacillosis, however, not all veterinary laboratories could perform these tests .

  17. Cohesive Properties of the Caulobacter crescentus Holdfast Adhesin Are Regulated by a Novel c-di-GMP Effector Protein

    Directory of Open Access Journals (Sweden)

    Kathrin S. Sprecher

    2017-03-01

    Full Text Available When encountering surfaces, many bacteria produce adhesins to facilitate their initial attachment and to irreversibly glue themselves to the solid substrate. A central molecule regulating the processes of this motile-sessile transition is the second messenger c-di-GMP, which stimulates the production of a variety of exopolysaccharide adhesins in different bacterial model organisms. In Caulobacter crescentus, c-di-GMP regulates the synthesis of the polar holdfast adhesin during the cell cycle, yet the molecular and cellular details of this control are currently unknown. Here we identify HfsK, a member of a versatile N-acetyltransferase family, as a novel c-di-GMP effector involved in holdfast biogenesis. Cells lacking HfsK form highly malleable holdfast structures with reduced adhesive strength that cannot support surface colonization. We present indirect evidence that HfsK modifies the polysaccharide component of holdfast to buttress its cohesive properties. HfsK is a soluble protein but associates with the cell membrane during most of the cell cycle. Coincident with peak c-di-GMP levels during the C. crescentus cell cycle, HfsK relocalizes to the cytosol in a c-di-GMP-dependent manner. Our results indicate that this c-di-GMP-mediated dynamic positioning controls HfsK activity, leading to its inactivation at high c-di-GMP levels. A short C-terminal extension is essential for the membrane association, c-di-GMP binding, and activity of HfsK. We propose a model in which c-di-GMP binding leads to the dispersal and inactivation of HfsK as part of holdfast biogenesis progression.

  18. Endocytosis-inducer adhesins produced by enteropathogenic serogroups of Escherichia coli participate on bacterial attachment to infant enterocytes

    Directory of Open Access Journals (Sweden)

    João Ramos Costa Andrade

    1987-03-01

    Full Text Available Enteropathogenic E. coli (EPEC infection of Hep-2 cells preoceeds through bacterial attachment to cell surface and internalization of adhered bacteria. EPEC attachment is a prerequisite for cell infection and is mediated by adhesins that recognize carbohydrate-containing receptors on cell membrane. Such endocytosis-inducer adhesins (EIA also promote EPEC binding to infant enterocytes, suggesting that EIA may have an important role on EPEC gastroenteritis.A infecção de células Hep-2 por E. coli enteropatogênicas (ECEP implica na aderência bacteriana e posterior interiorização dos microrganismos aderidos por um mecanismo de endocitose. A aderência das ECEP é pré-requisito para a infecção e é mediada por adesinas que reconhecem receptores inibidos por certas oses na membrana celular. Tais "adesinas indutoras da endocitose" (AIE também promovem a ligação bacteriana a enterócitos obtidos do intestino delgado de lactente, sugerindo que as AIE possam desempenhar algum papel nas diarréias causadas por ECEP.

  19. The role of filamentous hemagglutinin adhesin in adherence and biofilm formation in Acinetobacter baumannii ATCC19606(T).

    Science.gov (United States)

    Darvish Alipour Astaneh, Shakiba; Rasooli, Iraj; Mousavi Gargari, Seyed Latif

    2014-09-01

    Filamentous hemagglutinin adhesins (FHA) are key factors for bacterial attachment and subsequent cell accumulation on substrates. Here an FHA-like Outer membrane (OM) adhesin of Acinetobacter baumannii ATCC19606(T) was displayed on Escherichia coli. The candidate autotransporter (AT) genes were identified in A. baumannii ATCC19606(T) genome. The exoprotein (FhaB1) and transporter (FhaC1) were produced independently within the same cell (FhaB1C1). The fhaC1 was mutated. In vitro adherence to epithelial cells of the recombinant FhaB1C1 and the mutant strains were compared with A. baumanni ATCC19606(T). A bivalent chimeric protein (K) composed of immunologically important portions of fhaB1 (B) and fhaC1 (C) was constructed. The mice vaccinated with chimeric protein were challenged with A. baumannii ATCC19606(T) and FhaB1C1 producing recombinant E. coli. Mutations in the fhaC1 resulted in the absence of FhaB1 in the OM. Expression of FhaB1C1 enhanced the adherence of recombinant bacteria to A546 bronchial cell line. The results revealed association of FhaB1 with bacterial adhesion and biofilm formation. Immunization with a combination of recombinant B and K proteins proved protective against A. baumanni ATCC19606(T). The findings may be applied in active and passive immunization strategies against A. baumannii. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. N-terminal truncation enables crystallization of the receptor-binding domain of the FedF bacterial adhesin

    Energy Technology Data Exchange (ETDEWEB)

    De Kerpel, Maia; Van Molle, Inge [Department of Ultrastructure, Vrije Universiteit Brussel (VUB), Flanders Interuniversity Institute for Biotechnology (VIB), Pleinlaan 2, 1050 Brussels (Belgium); Brys, Lea [Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Flanders Interuniversity Institute for Biotechnology (VIB), Pleinlaan 2, 1050 Brussels (Belgium); Wyns, Lode; De Greve, Henri; Bouckaert, Julie, E-mail: bouckaej@vub.ac.be [Department of Ultrastructure, Vrije Universiteit Brussel (VUB), Flanders Interuniversity Institute for Biotechnology (VIB), Pleinlaan 2, 1050 Brussels (Belgium)

    2006-12-01

    The N-terminal receptor-binding domain of the FedF adhesin from enterotoxigenic E. coli has been crystallized. This required the deletion of its first 14 residues, which are also cleaved off naturally. FedF is the two-domain tip adhesin of F18 fimbriae from enterotoxigenic Escherichia coli. Bacterial adherence, mediated by the N-terminal receptor-binding domain of FedF to carbohydrate receptors on intestinal microvilli, causes diarrhoea and oedema disease in newly weaned piglets and induces the secretion of Shiga toxins. A truncate containing only the receptor-binding domain of FedF was found to be further cleaved at its N-terminus. Reconstruction of this N-terminal truncate rendered FedF amenable to crystallization, resulting in crystals with space group P2{sub 1}2{sub 1}2{sub 1} and unit-cell parameters a = 36.20, b = 74.64, c = 99.03 Å that diffracted to beyond 2 Å resolution. The binding specificity of FedF was screened for on a glycan array, exposing 264 glycoconjugates, to identify specific receptors for cocrystallization with FedF.

  1. Oligomeric coiled-coil adhesin YadA is a double-edged sword.

    Directory of Open Access Journals (Sweden)

    Salome Casutt-Meyer

    Full Text Available Yersinia adhesin A (YadA is an essential virulence factor for the food-borne pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis. Surprisingly, it is a pseudogene in Yersinia pestis. Even more intriguing, the introduction of a functional yadA gene in Y. pestis EV76 was shown to correlate with a decrease in virulence in a mouse model. Here, we report that wild type (wt Y. enterocolitica E40, as well as YadA-deprived E40 induced the synthesis of neutrophil extracellular traps (NETs upon contact with neutrophils, but only YadA-expressing Y. enterocolitica adhered to NETs and were killed. As binding seemed to be a prerequisite for killing, we searched for YadA-binding substrates and detected the presence of collagen within NETs. E40 bacteria expressing V98D,N99A mutant YadA with a severely reduced ability to bind collagen were found to be more resistant to killing, suggesting that collagen binding contributes significantly to sensitivity to NETs. Wt Y. pestis EV76 were resistant to killing by NETs, while recombinant EV76 expressing YadA from either Y. pseudotuberculosis or Y. enterocolitica were sensitive to killing by NETs, outlining the importance of YadA for susceptibility to NET-dependent killing. Recombinant EV76 endowed with YadA from Y. enterocolitica were also less virulent for the mouse than wt EV76, as shown before. In addition, EV76 carrying wt YadA were less virulent for the mouse than EV76 expressing YadA(V₉₈D,N₉₉A. The observation that YadA makes Yersinia sensitive to NETs provides an explanation as for why evolution selected for the inactivation of yadA in the flea-borne Y. pestis and clarifies an old enigma. Since YadA imposes the same cost to the food-borne Yersinia but was nevertheless conserved by evolution, this observation also illustrates the duality of some virulence functions.

  2. The anchorless adhesin Eap (extracellular adherence protein) from Staphylococcus aureus selectively recognizes extracellular matrix aggregates but binds promiscuously to monomeric matrix macromolecules

    NARCIS (Netherlands)

    Hansen, Uwe; Hussain, Muzaffar; Villone, Daniela; Herrmann, Mathias; Robenek, Horst; Peters, Georg; Sinha, Bhanu; Bruckner, Peter

    Besides a number of cell wall-anchored adhesins, the majority of Staphylococcus aureus strains produce anchorless, cell wall-associated proteins, such as Eap (extracellular adherence protein). Eap contains four to six tandem repeat (EAP)-domains. Eap mediates diverse biological functions, including

  3. Lactobacillus rhamnosus GG and its SpaC pilus adhesin modulate inflammatory responsiveness and TLR-related gene expression in the fetal human gut

    NARCIS (Netherlands)

    Ganguli, K.; Collado, M.C.; Rautava, J.; Lu, L.; Satokari, R.M.; Ossowski, von I.; Reunanen, J.; Vos, de W.M.; Palva, A.; Isolauri, E.; Salminen, S.; Walker, W.A.; Rautava, S.

    2015-01-01

    BACKGROUND: Bacterial contact in utero modulates fetal and neonatal immune responses. Maternal probiotic supplementation reduces the risk of immune-mediated disease in the infant. We investigated the immunomodulatory properties of live Lactobacillus rhamnosus GG and its SpaC pilus adhesin in human

  4. A Structural Model for Binding of the Serine-Rich Repeat Adhesin GspB to Host Carbohydrate Receptors

    Energy Technology Data Exchange (ETDEWEB)

    Pyburn, Tasia M.; Bensing, Barbara A.; Xiong, Yan Q.; Melancon, Bruce J.; Tomasiak, Thomas M.; Ward, Nicholas J.; Yankovskaya, Victoria; Oliver, Kevin M.; Cecchini, Gary; Sulikowski, Gary A.; Tyska, Matthew J.; Sullam, Paul M.; Iverson, T.M. (VA); (UCLA); (Vanderbilt); (UCSF)

    2014-10-02

    GspB is a serine-rich repeat (SRR) adhesin of Streptococcus gordonii that mediates binding of this organism to human platelets via its interaction with sialyl-T antigen on the receptor GPIb{alpha}. This interaction appears to be a major virulence determinant in the pathogenesis of infective endocarditis. To address the mechanism by which GspB recognizes its carbohydrate ligand, we determined the high-resolution x-ray crystal structure of the GspB binding region (GspB{sub BR}), both alone and in complex with a disaccharide precursor to sialyl-T antigen. Analysis of the GspB{sub BR} structure revealed that it is comprised of three independently folded subdomains or modules: (1) an Ig-fold resembling a CnaA domain from prokaryotic pathogens; (2) a second Ig-fold resembling the binding region of mammalian Siglecs; (3) a subdomain of unique fold. The disaccharide was found to bind in a pocket within the Siglec subdomain, but at a site distinct from that observed in mammalian Siglecs. Confirming the biological relevance of this binding pocket, we produced three isogenic variants of S. gordonii, each containing a single point mutation of a residue lining this binding pocket. These variants have reduced binding to carbohydrates of GPIb{alpha}. Further examination of purified GspB{sub BR}-R484E showed reduced binding to sialyl-T antigen while S. gordonii harboring this mutation did not efficiently bind platelets and showed a significant reduction in virulence, as measured by an animal model of endocarditis. Analysis of other SRR proteins revealed that the predicted binding regions of these adhesins also had a modular organization, with those known to bind carbohydrate receptors having modules homologous to the Siglec and Unique subdomains of GspBBR. This suggests that the binding specificity of the SRR family of adhesins is determined by the type and organization of discrete modules within the binding domains, which may affect the tropism of organisms for different tissues.

  5. Oral streptococci utilize a Siglec-like domain of serine-rich repeat adhesins to preferentially target platelet sialoglycans in human blood.

    Directory of Open Access Journals (Sweden)

    Lingquan Deng

    2014-12-01

    Full Text Available Damaged cardiac valves attract blood-borne bacteria, and infective endocarditis is often caused by viridans group streptococci. While such bacteria use multiple adhesins to maintain their normal oral commensal state, recognition of platelet sialoglycans provides an intermediary for binding to damaged valvular endocardium. We use a customized sialoglycan microarray to explore the varied binding properties of phylogenetically related serine-rich repeat adhesins, the GspB, Hsa, and SrpA homologs from Streptococcus gordonii and Streptococcus sanguinis species, which belong to a highly conserved family of glycoproteins that contribute to virulence for a broad range of Gram-positive pathogens. Binding profiles of recombinant soluble homologs containing novel sialic acid-recognizing Siglec-like domains correlate well with binding of corresponding whole bacteria to arrays. These bacteria show multiple modes of glycan, protein, or divalent cation-dependent binding to synthetic glycoconjugates and isolated glycoproteins in vitro. However, endogenous asialoglycan-recognizing clearance receptors are known to ensure that only fully sialylated glycans dominate in the endovascular system, wherein we find these particular streptococci become primarily dependent on their Siglec-like adhesins for glycan-mediated recognition events. Remarkably, despite an excess of alternate sialoglycan ligands in cellular and soluble blood components, these adhesins selectively target intact bacteria to sialylated ligands on platelets, within human whole blood. These preferred interactions are inhibited by corresponding recombinant soluble adhesins, which also preferentially recognize platelets. Our data indicate that circulating platelets may act as inadvertent Trojan horse carriers of oral streptococci to the site of damaged endocardium, and provide an explanation why it is that among innumerable microbes that gain occasional access to the bloodstream, certain viridans group

  6. A Constitutively Mannose-Sensitive Agglutinating Salmonella enterica subsp. enterica Serovar Typhimurium Strain, Carrying a Transposon in the Fimbrial Usher Gene stbC, Exhibits Multidrug Resistance and Flagellated Phenotypes

    Directory of Open Access Journals (Sweden)

    Kuan-Hsun Wu

    2012-01-01

    Full Text Available Static broth culture favors Salmonella enterica subsp. enterica serovar Typhimurium to produce type 1 fimbriae, while solid agar inhibits its expression. A transposon inserted in stbC, which would encode an usher for Stb fimbriae of a non-flagellar Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, conferred it to agglutinate yeast cells on both cultures. RT-PCR revealed that the expression of the fimbrial subunit gene fimA, and fimZ, a regulatory gene of fimA, were both increased in the stbC mutant when grown on LB agar; fimW, a repressor gene of fimA, exhibited lower expression. Flagella were observed in the stbC mutant and this phenotype was correlated with the motile phenotype. Microarray data and RT-PCR indicated that the expression of three genes, motA, motB, and cheM, was enhanced in the stbC mutant. The stbC mutant was resistant to several antibiotics, consistent with the finding that expression of yhcQ and ramA was enhanced. A complementation test revealed that transforming a recombinant plasmid possessing the stbC restored the mannose-sensitive agglutination phenotype to the stbC mutant much as that in the parental Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, indicating the possibility of an interplay of different fimbrial systems in coordinating their expression.

  7. Role of β1 integrins and bacterial adhesins for Yop injection into leukocytes in Yersinia enterocolitica systemic mouse infection.

    Science.gov (United States)

    Deuschle, Eva; Keller, Birgit; Siegfried, Alexandra; Manncke, Birgit; Spaeth, Tanja; Köberle, Martin; Drechsler-Hake, Doreen; Reber, Julia; Böttcher, Ralph T; Autenrieth, Stella E; Autenrieth, Ingo B; Bohn, Erwin; Schütz, Monika

    2016-02-01

    Injection of Yersinia outer proteins (Yops) into host cells by a type III secretion system is an important immune evasion mechanism of Yersinia enterocolitica (Ye). In this process Ye invasin (Inv) binds directly while Yersinia adhesin A (YadA) binds indirectly via extracellular matrix (ECM) proteins to β1 integrins on host cells. Although leukocytes turned out to be an important target of Yop injection by Ye, it was unclear which Ye adhesins and which leukocyte receptors are required for Yop injection. To explain this, we investigated the role of YadA, Inv and β1 integrins for Yop injection into leukocytes and their impact on the course of systemic Ye infection in mice. Ex vivo infection experiments revealed that adhesion of Ye via Inv or YadA is sufficient to promote Yop injection into leukocytes as revealed by a β-lactamase reporter assay. Serum factors inhibit YadA- but not Inv-mediated Yop injection into B and T cells, shifting YadA-mediated Yop injection in the direction of neutrophils and other myeloid cells. Systemic Ye mouse infection experiments demonstrated that YadA is essential for Ye virulence and Yop injection into leukocytes, while Inv is dispensable for virulence and plays only a transient and minor role for Yop injection in the early phase of infection. Ye infection of mice with β1 integrin-depleted leukocytes demonstrated that β1 integrins are dispensable for YadA-mediated Yop injection into leukocytes, but contribute to Inv-mediated Yop injection. Despite reduced Yop injection into leukocytes, β1 integrin-deficient mice exhibited an increased susceptibility for Ye infection, suggesting an important role of β1 integrins in immune defense against Ye. This study demonstrates that Yop injection into leukocytes by Ye is largely mediated by YadA exploiting, as yet unknown, leukocyte receptors. Copyright © 2015. Published by Elsevier GmbH.

  8. Phenotypical analysis of the Lactobacillus rhamnosus GG fimbrial spaFED operon: surface expression and functional characterization of recombinant SpaFED pili in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Johanna Rintahaka

    Full Text Available A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED any native expression of the SpaFED-called pili is still the subject of some uncertainty. Irrespective of such considerations, we decided it would be of relevance or interest to decipher the gross structure of this pilus type, and as well assess its functional capabilities for cellular adhesion and immunostimulation. For this, and by following the approach we had used previously to explicate the immuno-properties of SpaCBA pili, we constructed nisin-inducible expression clones producing either wild-type or SpaF pilin-deleted surface-assembled L. rhamnosus GG SpaFED pili on Lactococcus lactis cells. Using these piliated lactococcal constructs, we found that the pilin-polymerized architecture of a recombinant-produced SpaFED pilus coincides with sequence-based functional predictions of the related pilins, and in fact is prototypical of those other sortase-dependent pilus-like structures thus far characterized for piliated Gram-positive bacteria. Moreover, we confirmed that among the different pilin subunits encompassing spaFED operon-encoded pili, the SpaF pilin is a main adhesion determinant, and when present in the assembled structure can mediate pilus binding to mucus, certain extracellular matrix proteins, and different gut epithelial cell lines. However, somewhat unexpectedly, when recombinant SpaFED pili are surface-attached, we found that they could not potentiate the existing lactococcal cell-induced immune responses so elicited from intestinal- and immune-related cells, but rather instead, they could dampen them. Accordingly, we

  9. Phenotypical analysis of the Lactobacillus rhamnosus GG fimbrial spaFED operon: surface expression and functional characterization of recombinant SpaFED pili in Lactococcus lactis.

    Science.gov (United States)

    Rintahaka, Johanna; Yu, Xia; Kant, Ravi; Palva, Airi; von Ossowski, Ingemar

    2014-01-01

    A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA) is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED) any native expression of the SpaFED-called pili is still the subject of some uncertainty. Irrespective of such considerations, we decided it would be of relevance or interest to decipher the gross structure of this pilus type, and as well assess its functional capabilities for cellular adhesion and immunostimulation. For this, and by following the approach we had used previously to explicate the immuno-properties of SpaCBA pili, we constructed nisin-inducible expression clones producing either wild-type or SpaF pilin-deleted surface-assembled L. rhamnosus GG SpaFED pili on Lactococcus lactis cells. Using these piliated lactococcal constructs, we found that the pilin-polymerized architecture of a recombinant-produced SpaFED pilus coincides with sequence-based functional predictions of the related pilins, and in fact is prototypical of those other sortase-dependent pilus-like structures thus far characterized for piliated Gram-positive bacteria. Moreover, we confirmed that among the different pilin subunits encompassing spaFED operon-encoded pili, the SpaF pilin is a main adhesion determinant, and when present in the assembled structure can mediate pilus binding to mucus, certain extracellular matrix proteins, and different gut epithelial cell lines. However, somewhat unexpectedly, when recombinant SpaFED pili are surface-attached, we found that they could not potentiate the existing lactococcal cell-induced immune responses so elicited from intestinal- and immune-related cells, but rather instead, they could dampen them. Accordingly, we have now provided

  10. Enterotoxigenic Escherichia coli Adhesin-Toxoid Multiepitope Fusion Antigen CFA/I/II/IV-3xSTaN12S-mnLTG192G/L211A-Derived Antibodies Inhibit Adherence of Seven Adhesins, Neutralize Enterotoxicity of LT and STa Toxins, and Protect Piglets against Diarrhea.

    Science.gov (United States)

    Nandre, Rahul; Ruan, Xiaosai; Lu, Ti; Duan, Qiangde; Sack, David; Zhang, Weiping

    2018-03-01

    Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's diarrhea and travelers' diarrhea. Vaccines inducing antibodies to broadly inhibit bacterial adherence and to neutralize toxin enterotoxicity are expected to be effective against ETEC-associated diarrhea. 6×His-tagged adhesin-toxoid fusion proteins were shown to induce neutralizing antibodies to several adhesins and LT and STa toxins (X. Ruan, D. A. Sack, W. Zhang, PLoS One 10:e0121623, 2015, https://doi.org/10.1371/journal.pone.0121623). However, antibodies derived from His-tagged CFA/I/II/IV-2xSTa A14Q -dmLT or CFA/I/II/IV-2xSTa N12S -dmLT protein were less effective in neutralizing STa enterotoxicity and were not evaluated in vivo for efficacy against ETEC diarrhea. Additionally, His-tagged proteins are considered less desirable for human vaccines. In this study, we produced a tagless adhesin-toxoid MEFA (multiepitope fusion antigen) protein, enhanced anti-STa immunogenicity by including a third copy of STa toxoid STa N12S , and examined antigen immunogenicity in a murine model. Moreover, we immunized pregnant pigs with the tagless adhesin-toxoid MEFA protein and evaluated passive antibody protection against STa + or LT + ETEC infection in a pig challenge model. Results showed that tagless adhesin-toxoid MEFA CFA/I/II/IV-3xSTa N12S -mnLT R192G/L211A induced broad antiadhesin and antitoxin antibody responses in the intraperitoneally immunized mice and the intramuscularly immunized pigs. Mouse and pig serum antibodies significantly inhibited adherence of seven colonization factor antigen (CFA) adhesins (CFA/I and CS1 to CS6) and effectively neutralized both toxins. More importantly, suckling piglets born to the immunized mothers acquired antibodies and were protected against STa + ETEC and LT + ETEC diarrhea. These results indicated that tagless CFA/I/II/IV-3xSTa N12S -mnLT R192G/L211A induced broadly protective antiadhesin and antitoxin antibodies and demonstrate that this adhesin

  11. Pathogenesis of Human Diffusely Adhering Escherichia coli Expressing Afa/Dr Adhesins (Afa/Dr DAEC): Current Insights and Future Challenges

    Science.gov (United States)

    2014-01-01

    SUMMARY The pathogenicity and clinical pertinence of diffusely adhering Escherichia coli expressing the Afa/Dr adhesins (Afa/Dr DAEC) in urinary tract infections (UTIs) and pregnancy complications are well established. In contrast, the implication of intestinal Afa/Dr DAEC in diarrhea is still under debate. These strains are age dependently involved in diarrhea in children, are apparently not involved in diarrhea in adults, and can also be asymptomatic intestinal microbiota strains in children and adult. This comprehensive review analyzes the epidemiology and diagnosis and highlights recent progress which has improved the understanding of Afa/Dr DAEC pathogenesis. Here, I summarize the roles of Afa/Dr DAEC virulence factors, including Afa/Dr adhesins, flagella, Sat toxin, and pks island products, in the development of specific mechanisms of pathogenicity. In intestinal epithelial polarized cells, the Afa/Dr adhesins trigger cell membrane receptor clustering and activation of the linked cell signaling pathways, promote structural and functional cell lesions and injuries in intestinal barrier, induce proinflammatory responses, create angiogenesis, instigate epithelial-mesenchymal transition-like events, and lead to pks-dependent DNA damage. UTI-associated Afa/Dr DAEC strains, following adhesin-membrane receptor cell interactions and activation of associated lipid raft-dependent cell signaling pathways, internalize in a microtubule-dependent manner within urinary tract epithelial cells, develop a particular intracellular lifestyle, and trigger a toxin-dependent cell detachment. In response to Afa/Dr DAEC infection, the host epithelial cells generate antibacterial defense responses. Finally, I discuss a hypothetical role of intestinal Afa/Dr DAEC strains that can act as “silent pathogens” with the capacity to emerge as “pathobionts” for the development of inflammatory bowel disease and intestinal carcinogenesis. PMID:25278576

  12. Pathogenesis of human diffusely adhering Escherichia coli expressing Afa/Dr adhesins (Afa/Dr DAEC): current insights and future challenges.

    Science.gov (United States)

    Servin, Alain L

    2014-10-01

    The pathogenicity and clinical pertinence of diffusely adhering Escherichia coli expressing the Afa/Dr adhesins (Afa/Dr DAEC) in urinary tract infections (UTIs) and pregnancy complications are well established. In contrast, the implication of intestinal Afa/Dr DAEC in diarrhea is still under debate. These strains are age dependently involved in diarrhea in children, are apparently not involved in diarrhea in adults, and can also be asymptomatic intestinal microbiota strains in children and adult. This comprehensive review analyzes the epidemiology and diagnosis and highlights recent progress which has improved the understanding of Afa/Dr DAEC pathogenesis. Here, I summarize the roles of Afa/Dr DAEC virulence factors, including Afa/Dr adhesins, flagella, Sat toxin, and pks island products, in the development of specific mechanisms of pathogenicity. In intestinal epithelial polarized cells, the Afa/Dr adhesins trigger cell membrane receptor clustering and activation of the linked cell signaling pathways, promote structural and functional cell lesions and injuries in intestinal barrier, induce proinflammatory responses, create angiogenesis, instigate epithelial-mesenchymal transition-like events, and lead to pks-dependent DNA damage. UTI-associated Afa/Dr DAEC strains, following adhesin-membrane receptor cell interactions and activation of associated lipid raft-dependent cell signaling pathways, internalize in a microtubule-dependent manner within urinary tract epithelial cells, develop a particular intracellular lifestyle, and trigger a toxin-dependent cell detachment. In response to Afa/Dr DAEC infection, the host epithelial cells generate antibacterial defense responses. Finally, I discuss a hypothetical role of intestinal Afa/Dr DAEC strains that can act as "silent pathogens" with the capacity to emerge as "pathobionts" for the development of inflammatory bowel disease and intestinal carcinogenesis. Copyright © 2014, American Society for Microbiology. All Rights

  13. The Screw-Like Movement of a Gliding Bacterium Is Powered by Spiral Motion of Cell-Surface Adhesins.

    Science.gov (United States)

    Shrivastava, Abhishek; Roland, Thibault; Berg, Howard C

    2016-09-06

    Flavobacterium johnsoniae, a rod-shaped bacterium, glides over surfaces at speeds of ∼2 μm/s. The propulsion of a cell-surface adhesin, SprB, is known to enable gliding. We used cephalexin to generate elongated cells with irregular shapes and followed their displacement in three dimensions. These cells rolled about their long axes as they moved forward, following a right-handed trajectory. We coated gold nanoparticles with an SprB antibody and tracked them in three dimensions in an evanescent field where the nanoparticles appeared brighter when they were closer to the glass. The nanoparticles followed a right-handed spiral trajectory on the surface of the cell. Thus, if SprB were to adhere to the glass rather than to a nanoparticle, the cell would move forward along a right-handed trajectory, as observed, but in a direction opposite to that of the nanoparticle. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Serotype 3 pneumococci sequester platelet-derived human thrombospondin-1 via the adhesin and immune evasion protein Hic.

    Science.gov (United States)

    Binsker, Ulrike; Kohler, Thomas P; Krauel, Krystin; Kohler, Sylvia; Habermeyer, Johanna; Schwertz, Hansjörg; Hammerschmidt, Sven

    2017-04-07

    Streptococcus pneumoniae serotype 3 strains emerge frequently within clinical isolates of invasive diseases. Bacterial invasion into deeper tissues is associated with colonization and immune evasion mechanisms. Thus, pneumococci express a versatile repertoire of surface proteins sequestering and interacting specifically with components of the human extracellular matrix and serum. Hic, a PspC-like pneumococcal surface protein, possesses vitronectin and factor H binding activity. Here, we show that heterologously expressed Hic domains interact, similar to the classical PspC molecule, with human matricellular thrombospondin-1 (hTSP-1). Binding studies with isolated human thrombospondin-1 and various Hic domains suggest that the interaction between hTSP-1 and Hic differs from binding to vitronectin and factor H. Binding of Hic to hTSP-1 is inhibited by heparin and chondroitin sulfate A, indicating binding to the N-terminal globular domain or type I repeats of hTSP-1. Competitive inhibition experiments with other pneumococcal hTSP-1 adhesins demonstrated that PspC and PspC-like Hic recognize similar domains, whereas PavB and Hic can bind simultaneously to hTSP-1. In conclusion, Hic binds specifically hTSP-1; however, truncation in the N-terminal part of Hic decreases the binding activity, suggesting that the full length of the α-helical regions of Hic is required for an optimal interaction. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Trimeric autotransporter adhesins in members of the Burkholderia cepacia complex: a multifunctional family of proteins implicated in virulence

    Directory of Open Access Journals (Sweden)

    Arsénio Mendes Fialho

    2011-12-01

    Full Text Available Trimeric autotransporter adhesins (TAAs are multimeric surface proteins, involved in various biological traits of pathogenic Gram-negative bacteria including adherence, biofilm formation, invasion, survival within eukaryotic cells, serum resistance and cytotoxicity. TAAs have a modular architecture composed by a conserved membrane-anchored C-terminal domain and a variable number of stalk and head domains. In this study, a bioinformatic approach has been used to analyze the distribution and architecture of TAAs among Burkholderia cepacia complex (Bcc genomes. Fifteen genomes were probed revealing a total of 74 encoding sequences. Compared with other bacterial species, the Bcc genomes contain a disproportionately large number of TAAs (two genes to up to 8 genes, such as in B.cenocepacia. Phylogenetic analysis showed that the TAAs grouped into at least eight distinct clusters. TAAs with serine-rich repeats are clearly well separated from others, thereby representing a different evolutionary lineage. Comparative gene mapping across Bcc genomes reveals that TAA genes are inserted within conserved synteny blocks. We further focused our analysis on the epidemic strain B. cenocepacia J2315 in which 7 TAAs were annotated. Among these, 3 TAA-encoding genes (BCAM019, BCAM0223 and BCAM0224 are organized into a cluster and are candidates for multifunctional virulence factors. Here we review the current insights into the functional role of BCAM0224 as a model locus.

  16. Identification of Xylella fastidiosa antivirulence genes: hemagglutinin adhesins contribute a biofilm maturation to X. fastidios and colonization and attenuate virulence.

    Science.gov (United States)

    Guilhabert, Magalie R; Kirkpatrick, Bruce C

    2005-08-01

    Xylella fastidosa, a gram-negative, xylem-limited bacterium, is the causal agent of several economically important plant diseases, including Pierce's disease (PD) and citrus variegated chlorosis (CVC). Until recently, the inability to transform or produce transposon mutants of X. fastidosa had been a major impediment to identifying X. fastidosa genes that mediate pathogen and plant interactions. A random transposon (Tn5) library of X. fastidosa was constructed and screened for mutants showing more severe symptoms and earlier grapevine death (hypervirulence) than did vines infected with the wild type. Seven hypervirulent mutants identified in this screen moved faster and reached higher populations than the wild type in grapevines. These results suggest that X. fastidosa attenuates its virulence in planta and that movement is important in X. fastidosa virulence. The mutated genes were sequenced and none had been described previously as antivirulence genes, although six of them showed similarity with genes of known functions in other organisms. One transposon insertion inactivated a hemagglutinin adhesin gene (PD2118), which we named HxfA. Another mutant in a second putative X. fastidosa hemagglutinin gene, PD1792 (HxfB), was constructed, and further characterization of these hxf mutants suggests that X. fastidosa hemagglutinins mediate contact between X. fastidosa cells, which results in colony formation and biofilm maturation within the xylem vessels.

  17. The malate synthase of Paracoccidioides brasiliensis is a linked surface protein that behaves as an anchorless adhesin

    Directory of Open Access Journals (Sweden)

    Pereira Maristela

    2009-12-01

    Full Text Available Abstract Background The pathogenic fungus Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis (PCM. This is a pulmonary mycosis acquired by inhalation of fungal airborne propagules that can disseminate to several organs and tissues leading to a severe form of the disease. Adhesion and invasion to host cells are essential steps involved in the internalization and dissemination of pathogens. Inside the host, P. brasiliensis may use the glyoxylate cycle for intracellular survival. Results Here, we provide evidence that the malate synthase of P. brasiliensis (PbMLS is located on the fungal cell surface, and is secreted. PbMLS was overexpressed in Escherichia coli, and polyclonal antibody was obtained against this protein. By using Confocal Laser Scanning Microscopy, PbMLS was detected in the cytoplasm and in the cell wall of the mother, but mainly of budding cells of the P. brasiliensis yeast phase. PbMLSr and its respective polyclonal antibody produced against this protein inhibited the interaction of P. brasiliensis with in vitro cultured epithelial cells A549. Conclusion These observations indicated that cell wall-associated PbMLS could be mediating the binding of fungal cells to the host, thus contributing to the adhesion of fungus to host tissues and to the dissemination of infection, behaving as an anchorless adhesin.

  18. Staphylococcus epidermidis polysaccharide intercellular adhesin induces IL-8 expression in human astrocytes via a mechanism involving TLR2.

    LENUS (Irish Health Repository)

    Stevens, Niall T

    2009-03-01

    Staphylococcus epidermidis is an opportunistic biofilm-forming pathogen associated with neurosurgical device-related meningitis. Expression of the polysaccharide intercellular adhesin (PIA) on its surface promotes S. epidermidis biofilm formation. Here we investigated the pro-inflammatory properties of PIA against primary and transformed human astrocytes. PIA induced IL-8 expression in a dose- and\\/or time-dependent manner from U373 MG cells and primary normal human astrocytes. This effect was inhibited by depletion of N-acetyl-beta-d-glucosamine polymer from the PIA preparation with Lycopersicon esculentum lectin or sodium meta-periodate. Expression of dominant-negative versions of the TLR2 and TLR4 adaptor proteins MyD88 and Mal in U373 MG cells inhibited PIA-induced IL-8 production. Blocking IL-1 had no effect. PIA failed to induce IL-8 production from HEK293 cells stably expressing TLR4. However, in U373 MG cells which express TLR2, neutralization of TLR2 impaired PIA-induced IL-8 production. In addition to IL-8, PIA also induced expression of other cytokines from U373 MG cells including IL-6 and MCP-1. These data implicate PIA as an important immunogenic component of the S. epidermidis biofilm that can regulate pro-inflammatory cytokine production from human astrocytes, in part, via TLR2.

  19. MHJ_0125 is an M42 glutamyl aminopeptidase that moonlights as a multifunctional adhesin on the surface of Mycoplasma hyopneumoniae.

    Science.gov (United States)

    Robinson, Mark W; Buchtmann, Kyle A; Jenkins, Cheryl; Tacchi, Jessica L; Raymond, Benjamin B A; To, Joyce; Roy Chowdhury, Piklu; Woolley, Lauren K; Labbate, Maurizio; Turnbull, Lynne; Whitchurch, Cynthia B; Padula, Matthew P; Djordjevic, Steven P

    2013-04-17

    Bacterial aminopeptidases play important roles in pathogenesis by providing a source of amino acids from exogenous proteins, destroying host immunological effector peptides and executing posttranslational modification of bacterial and host proteins. We show that MHJ_0125 from the swine respiratory pathogen Mycoplasma hyopneumoniae represents a new member of the M42 class of bacterial aminopeptidases. Despite lacking a recognizable signal sequence, MHJ_0125 is detectable on the cell surface by fluorescence microscopy and LC-MS/MS of (i) biotinylated surface proteins captured by avidin chromatography and (ii) peptides released by mild trypsin shaving. Furthermore, surface-associated glutamyl aminopeptidase activity was detected by incubation of live M. hyopneumoniae cells with the diagnostic substrate H-Glu-AMC. MHJ_0125 moonlights as a multifunctional adhesin, binding to both heparin and plasminogen. Native proteomics and comparative modelling studies suggest MHJ_0125 forms a dodecameric, homopolymeric structure and provide insight into the positions of key residues that are predicted to interact with heparin and plasminogen. MHJ_0125 is the first aminopeptidase shown to both bind plasminogen and facilitate its activation by tissue plasminogen activator. Plasmin cleaves host extracellular matrix proteins and activates matrix metalloproteases, generating peptide substrates for MHJ_0125 and a source of amino acids for growth of M. hyopneumoniae. This unique interaction represents a new paradigm in microbial pathogenesis.

  20. Proteus mirabilis uroepithelial cell adhesin (UCA) fimbria plays a role in the colonization of the urinary tract.

    Science.gov (United States)

    Pellegrino, Rafael; Scavone, Paola; Umpiérrez, Ana; Maskell, Duncan J; Zunino, Pablo

    2013-03-01

    Urinary tract infections (UTIs) are among the most common bacterial infections in humans. Proteus mirabilis is an opportunistic pathogen, capable of causing severe UTIs, with serious kidney damage that may even lead to death. Several virulence factors are involved in the pathogenicity of this bacterium. Among these, adherence to the uroepithelium mediated by fimbriae appears to be a significant bacterial attribute related to urovirulence. Proteus mirabilis expresses several types of fimbriae that could be involved in the pathogenesis of UTI, including uroepithelial cell adhesin (UCA). In this report, we used an uropathogenic P. mirabilis wild-type strain and an isogenic ucaA mutant unable to express UCA to study the pathogenic role of this fimbria in UTI. Ability of the mutant to adhere to desquamated uroepithelial cells and to infect mice using different experimental UTI models was significantly impaired. These results allow us to conclude that P. mirabilis UCA plays an important role in the colonization of the urinary tract. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  1. NADH oxidase functions as an adhesin in Streptococcus pneumoniae and elicits a protective immune response in mice.

    Directory of Open Access Journals (Sweden)

    Lena Muchnik

    Full Text Available The initial event in disease caused by S. pneumoniae is adhesion of the bacterium to respiratory epithelial cells, mediated by surface expressed molecules including cell-wall proteins. NADH oxidase (NOX, which reduces free oxygen to water in the cytoplasm, was identified in a non-lectin enriched pneumococcal cell-wall fraction. Recombinant NOX (rNOX was screened with sera obtained longitudinally from children and demonstrated age-dependent immunogenicity. NOX ablation in S. pneumoniae significantly reduced bacterial adhesion to A549 epithelial cells in vitro and their virulence in the intranasal or intraperitoneal challenge models in mice, compared to the parental strain. Supplementation of Δnox WU2 with the nox gene restored its virulence. Saturation of A549 target cells with rNOX or neutralization of cell-wall residing NOX using anti-rNOX antiserum decreased adhesion to A549 cells. rNOX-binding phages inhibited bacterial adhesion. Moreover, peptides derived from the human proteins contactin 4, chondroitin 4 sulfotraferase and laminin5, homologous to the insert peptides in the neutralizing phages, inhibited bacterial adhesion to the A549 cells. Furthermore, rNOX immunization of mice elicited a protective immune response to intranasal or intraperitoneal S. pneumoniae challenge, whereas pneumococcal virulence was neutralized by anti-rNOX antiserum prior to intraperitoneal challenge. Our results suggest that in addition to its enzymatic activity, NOX contributes to S. pneumoniae virulence as a putative adhesin and thus peptides derived from its target molecules may be considered for the treatment of pneumococcal infections. Finally, rNOX elicited a protective immune response in both aerobic and anaerobic environments, which renders NOX a candidate for future pneumococcal vaccine.

  2. A repetitive DNA element regulates expression of the Helicobacter pylori sialic acid binding adhesin by a rheostat-like mechanism.

    Directory of Open Access Journals (Sweden)

    Anna Åberg

    2014-07-01

    Full Text Available During persistent infection, optimal expression of bacterial factors is required to match the ever-changing host environment. The gastric pathogen Helicobacter pylori has a large set of simple sequence repeats (SSR, which constitute contingency loci. Through a slipped strand mispairing mechanism, the SSRs generate heterogeneous populations that facilitate adaptation. Here, we present a model that explains, in molecular terms, how an intergenically located T-tract, via slipped strand mispairing, operates with a rheostat-like function, to fine-tune activity of the promoter that drives expression of the sialic acid binding adhesin, SabA. Using T-tract variants, in an isogenic strain background, we show that the length of the T-tract generates multiphasic output from the sabA promoter. Consequently, this alters the H. pylori binding to sialyl-Lewis x receptors on gastric mucosa. Fragment length analysis of post-infection isolated clones shows that the T-tract length is a highly variable feature in H. pylori. This mirrors the host-pathogen interplay, where the bacterium generates a set of clones from which the best-fit phenotypes are selected in the host. In silico and functional in vitro analyzes revealed that the length of the T-tract affects the local DNA structure and thereby binding of the RNA polymerase, through shifting of the axial alignment between the core promoter and UP-like elements. We identified additional genes in H. pylori, with T- or A-tracts positioned similar to that of sabA, and show that variations in the tract length likewise acted as rheostats to modulate cognate promoter output. Thus, we propose that this generally applicable mechanism, mediated by promoter-proximal SSRs, provides an alternative mechanism for transcriptional regulation in bacteria, such as H. pylori, which possesses a limited repertoire of classical trans-acting regulatory factors.

  3. Identification of a Supramolecular Functional Architecture of Streptococcus mutans Adhesin P1 on the Bacterial Cell Surface*

    Science.gov (United States)

    Heim, Kyle P.; Sullan, Ruby May A.; Crowley, Paula J.; El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Tang, Wenxing; Besingi, Richard; Dufrene, Yves F.; Brady, L. Jeannine

    2015-01-01

    P1 (antigen I/II) is a sucrose-independent adhesin of Streptococcus mutans whose functional architecture on the cell surface is not fully understood. S. mutans cells subjected to mechanical extraction were significantly diminished in adherence to immobilized salivary agglutinin but remained immunoreactive and were readily aggregated by fluid-phase salivary agglutinin. Bacterial adherence was restored by incubation of postextracted cells with P1 fragments that contain each of the two known adhesive domains. In contrast to untreated cells, glutaraldehyde-treated bacteria gained reactivity with anti-C-terminal monoclonal antibodies (mAbs), whereas epitopes recognized by mAbs against other portions of the molecule were masked. Surface plasmon resonance experiments demonstrated the ability of apical and C-terminal fragments of P1 to interact. Binding of several different anti-P1 mAbs to unfixed cells triggered release of a C-terminal fragment from the bacterial surface, suggesting a novel mechanism of action of certain adherence-inhibiting antibodies. We also used atomic force microscopy-based single molecule force spectroscopy with tips bearing various mAbs to elucidate the spatial organization and orientation of P1 on living bacteria. The similar rupture lengths detected using mAbs against the head and C-terminal regions, which are widely separated in the tertiary structure, suggest a higher order architecture in which these domains are in close proximity on the cell surface. Taken together, our results suggest a supramolecular organization in which additional P1 polypeptides, including the C-terminal segment originally identified as antigen II, associate with covalently attached P1 to form the functional adhesive layer. PMID:25666624

  4. Structural Basis for Toughness and Flexibility in the C-terminal Passenger Domain of an Acinetobacter Trimeric Autotransporter Adhesin*

    Science.gov (United States)

    Koiwai, Kotaro; Hartmann, Marcus D.; Linke, Dirk; Lupas, Andrei N.; Hori, Katsutoshi

    2016-01-01

    Trimeric autotransporter adhesins (TAAs) on the cell surface of Gram-negative pathogens mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific high adhesiveness to abiotic material surfaces as well as to biotic surfaces. It consists of a passenger domain secreted by the C-terminal transmembrane anchor domain (TM), and the passenger domain contains an N-terminal head, N-terminal stalk, C-terminal head (Chead), and C-terminal stalk (Cstalk). The Chead-Cstalk-TM fragment, which is conserved in many Acinetobacter TAAs, has by itself the head-stalk-anchor architecture of a complete TAA. Here, we show the crystal structure of the Chead-Cstalk fragment, AtaA_C-terminal passenger domain (CPSD), providing the first view of several conserved TAA domains. The YadA-like head (Ylhead) of the fragment is capped by a unique structure (headCap), composed of three β-hairpins and a connector motif; it also contains a head insert motif (HIM1) before its last inner β-strand. The headCap, Ylhead, and HIM1 integrally form a stable Chead structure. Some of the major domains of the CPSD fragment are inherently flexible and provide bending sites for the fiber between segments whose toughness is ensured by topological chain exchange and hydrophobic core formation inside the trimer. Thus, although adherence assays using in-frame deletion mutants revealed that the characteristic adhesive sites of AtaA reside in its N-terminal part, the flexibility and toughness of the CPSD part provide the resilience that enables the adhesive properties of the full-length fiber across a wide range of conditions. PMID:26698633

  5. Identification of a supramolecular functional architecture of Streptococcus mutans adhesin P1 on the bacterial cell surface.

    Science.gov (United States)

    Heim, Kyle P; Sullan, Ruby May A; Crowley, Paula J; El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Tang, Wenxing; Besingi, Richard; Dufrene, Yves F; Brady, L Jeannine

    2015-04-03

    P1 (antigen I/II) is a sucrose-independent adhesin of Streptococcus mutans whose functional architecture on the cell surface is not fully understood. S. mutans cells subjected to mechanical extraction were significantly diminished in adherence to immobilized salivary agglutinin but remained immunoreactive and were readily aggregated by fluid-phase salivary agglutinin. Bacterial adherence was restored by incubation of postextracted cells with P1 fragments that contain each of the two known adhesive domains. In contrast to untreated cells, glutaraldehyde-treated bacteria gained reactivity with anti-C-terminal monoclonal antibodies (mAbs), whereas epitopes recognized by mAbs against other portions of the molecule were masked. Surface plasmon resonance experiments demonstrated the ability of apical and C-terminal fragments of P1 to interact. Binding of several different anti-P1 mAbs to unfixed cells triggered release of a C-terminal fragment from the bacterial surface, suggesting a novel mechanism of action of certain adherence-inhibiting antibodies. We also used atomic force microscopy-based single molecule force spectroscopy with tips bearing various mAbs to elucidate the spatial organization and orientation of P1 on living bacteria. The similar rupture lengths detected using mAbs against the head and C-terminal regions, which are widely separated in the tertiary structure, suggest a higher order architecture in which these domains are in close proximity on the cell surface. Taken together, our results suggest a supramolecular organization in which additional P1 polypeptides, including the C-terminal segment originally identified as antigen II, associate with covalently attached P1 to form the functional adhesive layer. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Lsa30, a novel adhesin of Leptospira interrogans binds human plasminogen and the complement regulator C4bp.

    Science.gov (United States)

    Souza, Natalie M; Vieira, Monica L; Alves, Ivy J; de Morais, Zenaide M; Vasconcellos, Silvio A; Nascimento, Ana L T O

    2012-09-01

    Pathogenic Leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects populations worldwide. Surface proteins have the potential to promote several activities, including adhesion. This work aimed to study the leptospiral coding sequence (CDS) LIC11087, genome annotated as hypothetical outer membrane protein. The LIC11087 gene was cloned and expressed in Escherichia coli BL21 (DE3) strain by using the expression vector pAE. The recombinant protein tagged with N-terminal 6XHis was purified by metal-charged chromatography and characterized by circular dichroism (CD) spectroscopy. The recombinant protein has the ability to mediate attachment to the extracellular matrix (ECM) components, laminin and plasma fibronectin, and was named Lsa30 (Leptospiral surface adhesin of 30 kDa). Lsa30 binds to laminin and to plasma fibronectin in a dose-dependent and saturable manner, with dissociation equilibrium constants (K(D)) of 292 ± 24 nm and 157 ± 35 nm, respectively. Moreover, the Lsa30 is a plasminogen (PLG) receptor, capable of generating plasmin, in the presence of activator. This protein may interfere with the complement cascade by interacting with C4bp regulator. The Lsa30 is probably a new surface protein of Leptospira as revealed by immunofluorescence assays with living organisms and the reactivity with antibodies present in serum samples of experimentally infected hamsters. Thus, Lsa30 is a novel versatile protein that may play a role in mediating adhesion and may help pathogenic Leptospira to overcome tissue barriers and to escape the immune system. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. The LapG protein plays a role in Pseudomonas aeruginosa biofilm formation by controlling the presence of the CdrA adhesin on the cell surface

    DEFF Research Database (Denmark)

    Rybtke, Morten; Berthelsen, Jens; Yang, Liang

    2015-01-01

    Pseudomonas aeruginosa is a clinically relevant species involved in biofilm-based chronic infections. We provide evidence that the P. aeruginosa LapG protein functions as a periplasmic protease that can cleave the protein adhesin CdrA off the cell surface, and thereby plays a role in biofilm...... formation and biofilm dispersal. The P. aeruginosa LapG protein is shown to be a functional homolog of the Pseudomonas putida LapG protein which has previously been shown to function as a periplasmic protease that targets the surface adhesin LapA. Transposon mutagenesis and characterization of defined...... and whole-cell protein fractions showed that CdrA was retained in the whole-cell protein fraction when LapG was absent, whereas it was found in the culture supernatant when LapG was present. The finding that CdrA is a target of LapG in P. aeruginosa is surprising because CdrA has no homology to LapA....

  8. Expression, crystallization and preliminary X-ray data analysis of NT-Als9-2, a fungal adhesin from Candida albicans

    International Nuclear Information System (INIS)

    Salgado, Paula S.; Yan, Robert; Rowan, Fiona; Cota, Ernesto

    2011-01-01

    Details of the expression and crystallization of the N-terminal fragment of Als9-2, an adhesin from the human commensal/pathogenic fungus C. albicans, are reported. Preliminary analysis of the collected X-ray data is also discussed. Candida albicans is a common human fungal commensal that can also cause a range of infections from skin/mucosal ‘thrush’ to severe systemic candidiasis. Adherence to host cells is one of the key determinants of Candida pathogenesis. The Als family of surface proteins has been implicated in adhesion of C. albicans, yet limited information has been published on the structure and mechanism of these fungal adhesins. The N-terminal region of these proteins has been shown to possess adhesive properties, making it a possible target for new therapeutic strategies. Recombinant NT-Als9-2 from C. albicans (residues 18–329) was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.0 Å resolution. The crystals belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 34.73, b = 68.71, c = 120.03 Å, α = β = γ = 90° and one molecule in the asymmetric unit. Platinum-derivatized crystals belonged to the same space group, with similar unit-cell parameters, although they were not completely isomorphous

  9. Molecular simulations of lactose-bound and unbound forms of the FaeG adhesin reveal critical amino acids involved in sugar binding.

    Science.gov (United States)

    Baker, Joseph L; Jafri, Heba

    2016-11-01

    F4 fimbriae are protein filaments found in enterotoxigenic Escherichia coli cells and are implicated in the process of bacterial infection due to their function as bacterial adhesins. These filaments are comprised from several proteins, but the bacterial adhesin FaeG, which is a lactose-binding protein, is the major subunit comprising F4 fimbriae. Crystal structures for three variants of the FaeG protein were recently solved, including the ad variant of FaeG that was crystallized in complex with lactose. However, the dynamics of the FaeG protein bound to lactose have not been explored previously using molecular dynamics simulations. Therefore, in order to study the dynamical interactions between the FaeG ad variant and lactose, we have carried out the first all-atom molecular dynamics simulations of this system. We have also probed the role of crystallographic water molecules on the stability of lactose in the FaeG binding site, and have simulated seven FaeG mutants to probe the influence of amino acid substitutions on the ability of FaeG to bind lactose effectively. Our simulations agree well with experimental results for the influence of mutations on lactose binding, provide dynamical insights into the interactions of FaeG with lactose, and also suggest the possibility of additional regions of the FaeG protein that may act as secondary lactose binding sites. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Lactobacillus rhamnosus GG and its SpaC pilus adhesin modulate inflammatory responsiveness and TLR-related gene expression in the fetal human gut

    Science.gov (United States)

    Ganguli, Kriston; Collado, Maria Carmen; Rautava, Jaana; Lu, Lei; Satokari, Reetta; von Ossowski, Ingemar; Reunanen, Justus; de Vos, Willem M.; Palva, Airi; Isolauri, Erika; Salminen, Seppo; Walker, W. Allan; Rautava, Samuli

    2015-01-01

    Background Bacterial contact in utero modulates fetal and neonatal immune responses. Maternal probiotic supplementation reduces the risk of immune-mediated disease in the infant. We investigated the immunomodulatory properties of live Lactobacillus rhamnosus GG and its SpaC pilus adhesin in human fetal intestinal models. Methods TNF-α mRNA expression was measured by qPCR in a human fetal intestinal organ culture model exposed to live L. rhamnosus GG and proinflammatory stimuli. Binding of recombinant SpaC pilus protein to intestinal epithelial cells was assessed in human fetal intestinal organ culture and the human fetal intestinal epithelial cell line H4 by immunohistochemistry and immunofluorescence, respectively. TLR-related gene expression in fetal ileal organ culture after exposure to recombinant SpaC was assessed by qPCR. Results Live L. rhamnosus GG significantly attenuates pathogen-induced TNF-α mRNA expression in the human fetal gut. Recombinant SpaC protein was found to adhere to the fetal gut and to modulate varying levels of TLR-related gene expression. Conclusion The human fetal gut is responsive to luminal microbes. L. rhamnosus GG significantly attenuates fetal intestinal inflammatory responses to pathogenic bacteria. The L. rhamnosus GG pilus adhesin SpaC binds to immature human intestinal epithelial cells and directly modulates intestinal epithelial cell innate immune gene expression. PMID:25580735

  11. Proteolytic processing of the cilium adhesin MHJ_0194 (P123J ) in Mycoplasma hyopneumoniae generates a functionally diverse array of cleavage fragments that bind multiple host molecules.

    Science.gov (United States)

    Raymond, Benjamin B A; Jenkins, Cheryl; Seymour, Lisa M; Tacchi, Jessica L; Widjaja, Michael; Jarocki, Veronica M; Deutscher, Ania T; Turnbull, Lynne; Whitchurch, Cynthia B; Padula, Matthew P; Djordjevic, Steven P

    2015-03-01

    Mycoplasma hyopneumoniae, the aetiological agent of porcine enzootic pneumonia, regulates the presentation of proteins on its cell surface via endoproteolysis, including those of the cilial adhesin P123 (MHJ_0194). These proteolytic cleavage events create functional adhesins that bind to proteoglycans and glycoproteins on the surface of ciliated and non-ciliated epithelial cells and to the circulatory host molecule plasminogen. Two dominant cleavage events of the P123 preprotein have been previously characterized; however, immunoblotting studies suggest that more complex processing events occur. These extensive processing events are characterized here. The functional significance of the P97 cleavage fragments is also poorly understood. Affinity chromatography using heparin, fibronectin and plasminogen as bait and peptide arrays were used to expand our knowledge of the adhesive capabilities of P123 cleavage fragments and characterize a novel binding motif in the C-terminus of P123. Further, we use immunohistochemistry to examine in vivo, the biological significance of interactions between M. hyopneumoniae and fibronectin and show that M. hyopneumoniae induces fibronectin deposition at the site of infection on the ciliated epithelium. Our data supports the hypothesis that M. hyopneumoniae possesses the molecular machinery to influence key molecular communication pathways in host cells. © 2014 John Wiley & Sons Ltd.

  12. Streptococcal adhesin SspA/B analogue peptide inhibits adherence and impacts biofilm formation of Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Tatsuro Ito

    Full Text Available Streptococcus mutans, the major causative agent of dental caries, adheres to tooth surfaces via the host salivary glycoprotein-340 (gp340. This adherence can be competitively inhibited by peptides derived from the SspA/B adhesins of Streptococcus gordonii, a human commensal microbe that competes for the same binding sites. Ssp(A4K-A11K, a double-lysine substituted SspA/B peptide analogue, has been shown to exhibit superior in vitro binding affinity for a gp340-derived peptide (SRCRP2, suggesting that Ssp(A4K-A11K may be of clinical interest. In the present work, we tested the inhibitory effects of Ssp(A4K-A11K on adherence and biofilm formation of S. mutans by reconstructing an artificial oral environment using saliva-coated polystyrene plates and hydroxyapatite disks. Bacterial adherence (adherence period: 1 h was assessed by an enzyme-linked immunosorbent assay using biotinylated bacterial cells. Biofilm formation (periods: 8, 11, or 14 h was assessed by staining and imaging of the sessile cells, or by recovering biofilm cells and plating for cell counts. The pH values of the culture media were measured as a biofilm acidogenicity indicator. Bactericidality was measured by loss of optical density during culturing in the presence of the peptide. We observed that 650 μM Ssp(A4K-A11K significantly inhibited adherence of S. mutans to saliva-coated polystyrene; a similar effect was seen on bacterial affinity for SRCRP2. Ssp(A4K-A11K had lesser effects on the adherence of commensal streptococci. Pretreatment of polystyrene and hydroxyapatite with 650 μM Ssp(A4K-A11K significantly attenuated biofilm formation, whether tested with glucose- or sucrose-containing media. The SspA/B peptide's activity did not reflect bactericidality. Strikingly, pH in Ssp-treated 8-h (6.8 ± 0.06 and 11-h (5.5 ± 0.06 biofilms showed higher values than the critical pH. Thus, Ssp(A4K-A11K acts by inhibiting bacterial adherence and cariogrnic biofilm formation. We further

  13. Frequency of Fimbrial Virulence Genes (fim, pap, sfa in Escherichia Coli Isolated from the Patients with Urinary Tract Infections from selective hospitals of Tehran, Boroujerd and Sanandej City in 2015-2016

    Directory of Open Access Journals (Sweden)

    mohsen mirzaee

    2017-02-01

    Full Text Available Introduction: Urinary tract infection (UTI caused by E coli is one of the most common diseases in community. Colonization of E. coli and its attachment to the uroepithelium are mediated by adhesions such as P, Fim and S fimbriae. The present study was aimed to evaluate the prevalence of fimbrial virulence genes in Escherichia coli (E. coli isolates from the patients with urinary tract infection in Tehran, Boroujerd and Sanandaj cities, Iran. Methods: In this descriptive cross sectional study, 150 clinical isolates of uropathogenic E.coli were collected from the patients with urinary tract infection. All bacterial isolates were identified by standard biochemical laboratory methods; the fim, pap and sfa genes were detected using the PCR and Multiplex-PCR methods. Results: One hundred forty-five (96.66% isolates were positive for fim gene, one hundred forty (93.33% isolates were positive for pap gene and seven (4.66 isolates were positive for sfa gene. Whole of the isolates were possessed at least one of the three virulence genes. Six (4% isolates were positive for all genes. Conclusion: The findings of this study showed the high frequency of fim and P fimbriae among uropathogenic E.coli isolates from the patients with urinary tract infection. Because of the higher prevalence of UTI in the presence of these genes, detection of the genes in urine samples may help in more suspicious and rapid management of UTI.

  14. Transcriptional Analysis of the MrpJ Network: Modulation of Diverse Virulence-Associated Genes and Direct Regulation of mrp Fimbrial and flhDC Flagellar Operons in Proteus mirabilis

    Science.gov (United States)

    Bode, Nadine J.; Debnath, Irina; Kuan, Lisa; Schulfer, Anjelique; Ty, Maureen

    2015-01-01

    The enteric bacterium Proteus mirabilis is associated with a significant number of catheter-associated urinary tract infections (UTIs). Strict regulation of the antagonistic processes of adhesion and motility, mediated by fimbriae and flagella, respectively, is essential for disease progression. Previously, the transcriptional regulator MrpJ, which is encoded by the mrp fimbrial operon, has been shown to repress both swimming and swarming motility. Here we show that MrpJ affects an array of cellular processes beyond adherence and motility. Microarray analysis found that expression of mrpJ mimicking levels observed during UTIs leads to differential expression of 217 genes related to, among other functions, bacterial virulence, type VI secretion, and metabolism. We probed the molecular mechanism of transcriptional regulation by MrpJ using transcriptional reporters and chromatin immunoprecipitation (ChIP). Binding of MrpJ to two virulence-associated target gene promoters, the promoters of the flagellar master regulator flhDC and mrp itself, appears to be affected by the condensation state of the native chromosome, although both targets share a direct MrpJ binding site proximal to the transcriptional start. Furthermore, an mrpJ deletion mutant colonized the bladders of mice at significantly lower levels in a transurethral model of infection. Additionally, we observed that mrpJ is widely conserved in a collection of recent clinical isolates. Altogether, these findings support a role of MrpJ as a global regulator of P. mirabilis virulence. PMID:25847961

  15. An N-terminal Retention Module Anchors the Giant Adhesin LapA of Pseudomonas fluorescens at the Cell Surface: A Novel Sub-family of Type I Secretion Systems.

    Science.gov (United States)

    Smith, T Jarrod; Font, Maria E; Kelly, Carolyn M; Sondermann, Holger; O'Toole, George A

    2018-02-05

    LapA of Pseudomonas fluorescens Pf0-1 belongs to a diverse family of cell surface associated bacterial adhesins that are secreted via the type-1 secretion system (T1SS). We previously reported that the periplasmic protease LapG cleaves the N-terminus of LapA at a canonical dialanine motif to release the adhesin from the cell surface under conditions unfavorable to biofilm formation, thus decreasing biofilm formation. Here, we characterize LapA as the first type 1 secreted substrate that does not follow the "one-step" rule of T1SS. Rather, a novel N-terminal element, called the retention module (RM), localizes LapA at the cell surface as a secretion intermediate. Our genetic, biochemical, and molecular modeling analysis support a model wherein LapA is tethered to the cell surface through its T1SS outer membrane TolC-like pore, LapE, until LapG cleaves LapA in the periplasm. We further demonstrate this unusual retention strategy is likely conserved among LapA-like proteins, and reveals a new subclass of T1SS ABC transporters involved in transporting this group of surface-associated, LapA-like adhesins. These studies demonstrate a novel cell surface retention strategy used throughout the Proteobacteria and highlight a previously unappreciated flexibility of function for T1SS. Importance. Bacteria have evolved multiple secretion strategies to interact with their environment. For many bacteria, the secretion of cell surface associated adhesins is key for initiating contact with a preferred substratum to facilitate biofilm formation. Our work demonstrates that P. fluorescens uses a previously unrecognized secretion strategy to retain the giant adhesin LapA at its cell surface. Further, we identify likely LapA-like adhesins in various pathogenic and commensal Proteobacteria and provide phylogenetic evidence that these adhesins are secreted by a new subclass of T1SS ABC transporters. Copyright © 2018 American Society for Microbiology.

  16. Helicobacter pylori Type IV Secretion System and Its Adhesin Subunit, CagL, Mediate Potent Inflammatory Responses in Primary Human Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Mona Tafreshi

    2018-02-01

    Full Text Available The Gram-negative bacterium, Helicobacter pylori, causes chronic gastritis, peptic ulcers, and gastric cancer in humans. Although the gastric epithelium is the primary site of H. pylori colonization, H. pylori can gain access to deeper tissues. Concurring with this notion, H. pylori has been found in the vicinity of endothelial cells in gastric submucosa. Endothelial cells play crucial roles in innate immune response, wound healing and tumorigenesis. This study examines the molecular mechanisms by which H. pylori interacts with and triggers inflammatory responses in endothelial cells. We observed that H. pylori infection of primary human endothelial cells stimulated secretion of the key inflammatory cytokines, interleukin-6 (IL-6 and interleukin-8 (IL-8. In particular, IL-8, a potent chemokine and angiogenic factor, was secreted by H. pylori-infected endothelial cells to levels ~10- to 20-fold higher than that typically observed in H. pylori-infected gastric epithelial cells. These inflammatory responses were triggered by the H. pylori type IV secretion system (T4SS and the T4SS-associated adhesin CagL, but not the translocation substrate CagA. Moreover, in contrast to integrin α5β1 playing an essential role in IL-8 induction by H. pylori upon infection of gastric epithelial cells, both integrin α5β1 and integrin αvβ3 were dispensable for IL-8 induction in H. pylori-infected endothelial cells. However, epidermal growth factor receptor (EGFR is crucial for mediating the potent H. pylori-induced IL-8 response in endothelial cells. This study reveals a novel mechanism by which the H. pylori T4SS and its adhesin subunit, CagL, may contribute to H. pylori pathogenesis by stimulating the endothelial innate immune responses, while highlighting EGFR as a potential therapeutic target for controlling H. pylori-induced inflammation.

  17. Transcriptional analysis of the MrpJ network: modulation of diverse virulence-associated genes and direct regulation of mrp fimbrial and flhDC flagellar operons in Proteus mirabilis.

    Science.gov (United States)

    Bode, Nadine J; Debnath, Irina; Kuan, Lisa; Schulfer, Anjelique; Ty, Maureen; Pearson, Melanie M

    2015-06-01

    The enteric bacterium Proteus mirabilis is associated with a significant number of catheter-associated urinary tract infections (UTIs). Strict regulation of the antagonistic processes of adhesion and motility, mediated by fimbriae and flagella, respectively, is essential for disease progression. Previously, the transcriptional regulator MrpJ, which is encoded by the mrp fimbrial operon, has been shown to repress both swimming and swarming motility. Here we show that MrpJ affects an array of cellular processes beyond adherence and motility. Microarray analysis found that expression of mrpJ mimicking levels observed during UTIs leads to differential expression of 217 genes related to, among other functions, bacterial virulence, type VI secretion, and metabolism. We probed the molecular mechanism of transcriptional regulation by MrpJ using transcriptional reporters and chromatin immunoprecipitation (ChIP). Binding of MrpJ to two virulence-associated target gene promoters, the promoters of the flagellar master regulator flhDC and mrp itself, appears to be affected by the condensation state of the native chromosome, although both targets share a direct MrpJ binding site proximal to the transcriptional start. Furthermore, an mrpJ deletion mutant colonized the bladders of mice at significantly lower levels in a transurethral model of infection. Additionally, we observed that mrpJ is widely conserved in a collection of recent clinical isolates. Altogether, these findings support a role of MrpJ as a global regulator of P. mirabilis virulence. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. Emerging ST121/agr4 community-associated methicillin-resistant Staphylococcus aureus (MRSA with strong adhesin and cytolytic activities: trigger for MRSA pneumonia and fatal aspiration pneumonia in an influenza-infected elderly

    Directory of Open Access Journals (Sweden)

    T.-W. Wan

    2016-09-01

    Full Text Available The pathogenesis of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA pneumonia in influenza-infected elderly individuals has not yet been elucidated in detail. In the present study, a 92-year-old man infected with influenza developed CA-MRSA pneumonia. His CA-MRSA was an emerging type, originated in ST121/agr4 S. aureus, with diversities of Panton–Valentine leucocidin (PVL−/spat5110/SCCmecV+ versus PVL+/spat159(etc./SCCmec−, but with common virulence potentials of strong adhesin and cytolytic activities. Resistance to erythromycin/clindamycin (inducible-type and gentamicin was detected. Pneumonia improved with the administration of levofloxacin, but with the subsequent development of fatal aspiration pneumonia. Hence, characteristic CA-MRSA with strong adhesin and cytolytic activities triggered influenza-related sequential complications.

  19. Immunologic properties and therapeutic efficacy of a multivalent epitope-based vaccine against four Helicobacter pylori adhesins (urease, Lpp20, HpaA, and CagL) in Mongolian gerbils.

    Science.gov (United States)

    Guo, Le; Yin, Runting; Xu, Guangxian; Gong, Xiaojuan; Chang, Zisong; Hong, Dantong; Liu, Hongpeng; Ding, Shuqin; Han, Xuebo; Li, Yuan; Tang, Feng; Liu, Kunmei

    2017-12-01

    Therapeutic vaccination is a desirable alternative for controlling Helicobacter pylori (H. pylori) infection. Attachment to the gastric mucosa is the first step in establishing bacterial colonization, and adhesins, which are on the surface of H. pylori, play a pivotal role in binding to human gastric mucosa. In the present study, we constructed a multivalent epitope-based vaccine named CFAdE with seven carefully selected antigenic fragments from four H. pylori adhesins (urease, Lpp20, HpaA and CagL). The specificity, immunogenicity and ability to produce neutralizing antibodies of CFAdE were evaluated in BALB/c mice. After that, its therapeutic efficacy and protective immune mechanisms were explored in H. pylori-infected Mongolian gerbils. The results indicated that CFAdE could induce comparatively high levels of specific antibodies against urease, Lpp20, HpaA and CagL. Additionally, oral therapeutic immunization with CFAdE plus polysaccharide adjuvant (PA) significantly decreased H. pylori colonization compared with oral immunization with urease plus PA, and the protection was correlated with IgG and sIgA antibody and antigen-specific CD4 + T cells. This study indicated that the multivalent epitope-based vaccine, which targeted multiple adhesins in adherence of H. pylori to the gastric mucosa, is more effective than the univalent vaccine targeting urease only. This multivalent epitope-based vaccine may be a promising therapeutic candidate vaccine against H. pylori infection. © 2017 John Wiley & Sons Ltd.

  20. The Extracellular Protein Factor Epf from Streptococcus pyogenes Is a Cell Surface Adhesin That Binds to Cells through an N-terminal Domain Containing a Carbohydrate-binding Module*

    Science.gov (United States)

    Linke, Christian; Siemens, Nikolai; Oehmcke, Sonja; Radjainia, Mazdak; Law, Ruby H. P.; Whisstock, James C.; Baker, Edward N.; Kreikemeyer, Bernd

    2012-01-01

    Streptococcus pyogenes is an exclusively human pathogen. Streptococcal attachment to and entry into epithelial cells is a prerequisite for a successful infection of the human host and requires adhesins. Here, we demonstrate that the multidomain protein Epf from S. pyogenes serotype M49 is a streptococcal adhesin. An epf-deficient mutant showed significantly decreased adhesion to and internalization into human keratinocytes. Cell adhesion is mediated by the N-terminal domain of Epf (EpfN) and increased by the human plasma protein plasminogen. The crystal structure of EpfN, solved at 1.6 Å resolution, shows that it consists of two subdomains: a carbohydrate-binding module and a fibronectin type III domain. Both fold types commonly participate in ligand receptor and protein-protein interactions. EpfN is followed by 18 repeats of a domain classified as DUF1542 (domain of unknown function 1542) and a C-terminal cell wall sorting signal. The DUF1542 repeats are not involved in adhesion, but biophysical studies show they are predominantly α-helical and form a fiber-like stalk of tandem DUF1542 domains. Epf thus conforms with the widespread family of adhesins known as MSCRAMMs (microbial surface components recognizing adhesive matrix molecules), in which a cell wall-attached stalk enables long range interactions via its adhesive N-terminal domain. PMID:22977243

  1. The extracellular protein factor Epf from Streptococcus pyogenes is a cell surface adhesin that binds to cells through an N-terminal domain containing a carbohydrate-binding module.

    Science.gov (United States)

    Linke, Christian; Siemens, Nikolai; Oehmcke, Sonja; Radjainia, Mazdak; Law, Ruby H P; Whisstock, James C; Baker, Edward N; Kreikemeyer, Bernd

    2012-11-02

    Streptococcus pyogenes is an exclusively human pathogen. Streptococcal attachment to and entry into epithelial cells is a prerequisite for a successful infection of the human host and requires adhesins. Here, we demonstrate that the multidomain protein Epf from S. pyogenes serotype M49 is a streptococcal adhesin. An epf-deficient mutant showed significantly decreased adhesion to and internalization into human keratinocytes. Cell adhesion is mediated by the N-terminal domain of Epf (EpfN) and increased by the human plasma protein plasminogen. The crystal structure of EpfN, solved at 1.6 Å resolution, shows that it consists of two subdomains: a carbohydrate-binding module and a fibronectin type III domain. Both fold types commonly participate in ligand receptor and protein-protein interactions. EpfN is followed by 18 repeats of a domain classified as DUF1542 (domain of unknown function 1542) and a C-terminal cell wall sorting signal. The DUF1542 repeats are not involved in adhesion, but biophysical studies show they are predominantly α-helical and form a fiber-like stalk of tandem DUF1542 domains. Epf thus conforms with the widespread family of adhesins known as MSCRAMMs (microbial surface components recognizing adhesive matrix molecules), in which a cell wall-attached stalk enables long range interactions via its adhesive N-terminal domain.

  2. Prevalence of adhesin and toxin genes in E. coli strains isolated from diarrheic and non-diarrheic pigs from smallholder herds in northern and eastern Uganda.

    Science.gov (United States)

    Ikwap, Kokas; Larsson, Jenny; Jacobson, Magdalena; Owiny, David Okello; Nasinyama, George William; Nabukenya, Immaculate; Mattsson, Sigbrit; Aspan, Anna; Erume, Joseph

    2016-08-05

    Enterotoxigenic E. coli (ETEC) significantly contribute to diarrhea in piglets and weaners. The smallholder pig producers in Uganda identified diarrhea as one of the major problems especially in piglets. The aim of this study was to; i) characterize the virulence factors of E. coli strains isolated from diarrheic and non-diarrheic suckling piglets and weaners from smallholder herds in northern and eastern Uganda and ii) identify and describe the post-mortem picture of ETEC infection in severely diarrheic piglets. Rectal swab samples were collected from 83 piglets and weaners in 20 herds and isolated E. coli were characterized by PCR, serotyping and hemolysis. The E. coli strains carried genes for the heat stable toxins STa, STb and EAST1 and adhesins F4 and AIDA-I. The genes for the heat labile toxin LT and adhesins F5, F6, F18 and F41 were not detected in any of the E. coli isolates. Where the serogroup could be identified, E. coli isolates from the same diarrheic pig belonged to the same serogroup. The prevalence of EAST1, STb, Stx2e, STa, AIDA-I, and F4 in the E. coli isolates from suckling piglets and weaners (diarrheic and non-diarrheic combined) was 29, 26.5, 2.4, 1.2, 16, and 8.4 %, respectively. However the prevalence of F4 and AIDA-I in E. coli from diarrheic suckling piglets alone was 22.2 and 20 %, respectively. There was no significant difference in the prevalence of the individual virulence factors in E. coli from the diarrheic and non-diarrheic pigs (p > 0.05). The main ETEC strains isolated from diarrheic and non-diarrheic pigs included F4/STb/EAST1 (7.2 %), F4/STb (1.2 %), AIDA/STb/EAST1 (8 %) and AIDA/STb (8 %). At post-mortem, two diarrheic suckling piglets carrying ETEC showed intact intestinal villi, enterocytes and brush border but with a layer of cells attached to the brush border, suggestive of ETEC infections. This study has shown that the F4 fimbriae is the most predominant in E. coli from diarrheic piglets in the study area and

  3. Co-ordinate action of bacterial adhesins and human carcinoembryonic antigen receptors in enhanced cellular invasion by capsulate serum resistant Neisseria meningitidis.

    Science.gov (United States)

    Rowe, Helen A; Griffiths, Natalie J; Hill, Darryl J; Virji, Mumtaz

    2007-01-01

    Neisseria meningitidis (Nm) is a human specific opportunistic pathogen that occasionally penetrates mucosal barriers via the action of adhesins and invasins and evades host immune mechanisms during further dissemination via capsule expression. From in vitro studies, the primary adhesion of capsulate bacteria is believed to be mediated by polymeric pili, followed by invasion via outer membrane adhesins such as Opa proteins. As the latter requires the surface capsule to be down-modulated, invading bacteria would be serum sensitive and thus avirulent. However, there is recent evidence that capsulate bacteria may interact via Opa proteins when host cells express high levels of carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), their target receptors. Such a situation may arise following increased circulation of inflammatory cytokines that upregulate certain adhesion molecules on host cells. In this study, using a tetracycline controlled expression system, we have developed cell lines with inducible CEACAM expression to mimic post-inflammation state of target tissues and analysed the interplay between the three surface components capsule, pili and Opa proteins in cellular interactions. With two distinct cell lines, not only the level but also the rate of adhesion of capsulate Opa-expressing Nm increased concurrently with CEACAM density. Moreover, when threshold levels of receptor were reached, cellular invasion ensued in an Opa-dependent manner. In studies with cell lines intrinsically expressing pilus receptors, notable synergism in cellular interactions between pili and Opa of several meningococcal strains was observed and was independent of capsule type. A number of internalized bacteria were shown to express capsule and when directly isolated from host cells, these bacteria were as serum resistant as the inoculated phenotype. Furthermore, we observed that agents that block Opa-CEACAM binding substantially reduced cellular invasion, while maintaining

  4. Design

    DEFF Research Database (Denmark)

    Volf, Mette

    This publication is unique in its demystification and operationalization of the complex and elusive nature of the design process. The publication portrays the designer’s daily work and the creative process, which the designer is a part of. Apart from displaying the designer’s work methods...... and design parameters, the publication shows examples from renowned Danish design firms. Through these examples the reader gets an insight into the designer’s reality....

  5. Burkholderia cenocepacia K56-2 trimeric autotransporter adhesin BcaA binds TNFR1 and contributes to induce airway inflammation.

    Science.gov (United States)

    Mil-Homens, Dalila; Pinto, Sandra N; Matos, Rute G; Arraiano, Cecília; Fialho, Arsenio M

    2017-04-01

    Chronic lung disease caused by persistent bacterial infections is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). CF pathogens acquire antibiotic resistance, overcome host defenses, and impose uncontrolled inflammation that ultimately may cause permanent damage of lungs' airways. Among the multiple CF-associated pathogens, Burkholderia cenocepacia and other Burkholderia cepacia complex bacteria have become prominent contributors of disease progression. Here, we demonstrate that BcaA, a trimeric autotransporter adhesin (TAA) from the epidemic strain B. cenocepacia K56-2, is a tumor necrosis factor receptor 1-interacting protein able to regulate components of the tumor necrosis factor signaling pathway and ultimately leading to a significant production of the proinflammatory cytokine IL-8. Notably, this study is the first to demonstrate that a protein belonging to the TAA family is involved in the induction of the inflammatory response during B. cenocepacia infections, contributing to the success of the pathogen. Moreover, our results reinforce the relevance of the TAA BcaA as a multifunctional protein with a major role in B. cenocepacia virulence. © 2016 John Wiley & Sons Ltd.

  6. A functional collagen adhesin gene, acm, in clinical isolates of Enterococcus faecium correlates with the recent success of this emerging nosocomial pathogen.

    Science.gov (United States)

    Nallapareddy, Sreedhar R; Singh, Kavindra V; Okhuysen, Pablo C; Murray, Barbara E

    2008-09-01

    Enterococcus faecium recently evolved from a generally avirulent commensal into a multidrug-resistant health care-associated pathogen causing difficult-to-treat infections, but little is known about the factors responsible for this change. We previously showed that some E. faecium strains express a cell wall-anchored collagen adhesin, Acm. Here we analyzed 90 E. faecium isolates (99% acm(+)) and found that the Acm protein was detected predominantly in clinically derived isolates, while the acm gene was present as a transposon-interrupted pseudogene in 12 of 47 isolates of nonclinical origin. A highly significant association between clinical (versus fecal or food) origin and collagen adherence (P Acm detected by whole-cell enzyme-linked immunosorbent assay and flow cytometry. Thirty-seven of 41 sera from patients with E. faecium infections showed reactivity with recombinant Acm, while only 4 of 30 community and hospitalized patient control group sera reacted (P Acm were present in all 14 E. faecium endocarditis patient sera. Although pulsed-field gel electrophoresis indicated that multiple strains expressed collagen adherence, multilocus sequence typing demonstrated that the majority of collagen-adhering isolates, as well as 16 of 17 endocarditis isolates, are part of the hospital-associated E. faecium genogroup referred to as clonal complex 17 (CC17), which has emerged globally. Taken together, our findings support the hypothesis that Acm has contributed to the emergence of E. faecium and CC17 in nosocomial infections.

  7. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Wenxing; Bhatt, Avni [University of Florida, Department of Biochemistry and Molecular Biology, College of Medicine (United States); Smith, Adam N. [University of Florida, Department of Chemistry, College of Liberal Arts and Sciences (United States); Crowley, Paula J.; Brady, L. Jeannine, E-mail: jbrady@dental.ufl.edu [University of Florida, Department of Oral Biology, College of Dentistry (United States); Long, Joanna R., E-mail: jrlong@ufl.edu [University of Florida, Department of Biochemistry and Molecular Biology, College of Medicine (United States)

    2016-02-15

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ∼57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin.

  8. Detection of fusobacterium nucleatum and fadA adhesin gene in patients with orthodontic gingivitis and non-orthodontic periodontal inflammation.

    Science.gov (United States)

    Liu, Ping; Liu, Yi; Wang, Jianning; Guo, Yang; Zhang, Yujie; Xiao, Shuiqing

    2014-01-01

    Fusobacterium nucleatum is one of the most abundant gram-negative bacilli colonizing the subgingival plaque and closely associated with periodontal disease. However it is unclear whether F. nucleatum is involved in gingival inflammation under orthodontic appliance. A novel adhesin, FadA, which is unique to oral Fusobacteria, is required for F. nucleatum binding and invasion to epithelial cells and thus may play an important role in colonization of Fusobacterium in the host. In this study, we evaluated the prevalence of F. nucleatum and its virulence factor FadA adhesion gene (fadA) in 169 subgingival biofilm samples from 55 cases of gingivitis patients with orthodontic appliances, 49 cases of gingivitis patients without orthodontic treatment, 35 cases of periodontitis patients and 30 cases of periodontally healthy people via PCR. The correlations between the F. nucleatum/fadA and gingivitis index(GI)was also analyzed. The detection rate of F. nucleatum/fadA in periodontitis group and non-orthodontic gingivitis group was higher than the other two groups (pgingivitis group than in health people (pgingivitis and periodontal disease compared with orthodontic gingivitis.

  9. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy

    International Nuclear Information System (INIS)

    Tang, Wenxing; Bhatt, Avni; Smith, Adam N.; Crowley, Paula J.; Brady, L. Jeannine; Long, Joanna R.

    2016-01-01

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ∼57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin

  10. O-mannosylation of the Mycobacterium tuberculosis adhesin Apa is crucial for T cell antigenicity during infection but is expendable for protection.

    Science.gov (United States)

    Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M; Lucas, Megan; Spencer, John S; Fang, Sunan; McDonald, Melissa A; Pohl, Jan; Birkness, Kristin; Chamcha, Venkateswarlu; Ramirez, Melissa V; Plikaytis, Bonnie B; Posey, James E; Amara, Rama Rao; Sable, Suraj B

    2013-01-01

    Glycosylation is the most abundant post-translational polypeptide chain modification in nature. Although carbohydrate modification of protein antigens from many microbial pathogens constitutes important components of B cell epitopes, the role in T cell immunity is not completely understood. Here, using ELISPOT and polychromatic flow cytometry, we show that O-mannosylation of the adhesin, Apa, of Mycobacterium tuberculosis (Mtb) is crucial for its T cell antigenicity in humans and mice after infection. However, subunit vaccination with both mannosylated and non-mannosylated Apa induced a comparable magnitude and quality of T cell response and imparted similar levels of protection against Mtb challenge in mice. Both forms equally improved waning BCG vaccine-induced protection in elderly mice after subunit boosting. Thus, O-mannosylation of Apa is required for antigenicity but appears to be dispensable for its immunogenicity and protective efficacy in mice. These results have implications for the development of subunit vaccines using post-translationally modified proteins such as glycoproteins against infectious diseases like tuberculosis.

  11. Enhanced effect of BCG vaccine against pulmonary Mycobacterium tuberculosis infection in mice with lung Th17 response to mycobacterial heparin-binding hemagglutinin adhesin antigen.

    Science.gov (United States)

    Fukui, Masayuki; Shinjo, Kikuko; Umemura, Masayuki; Shigeno, Satoko; Harakuni, Tetsuya; Arakawa, Takeshi; Matsuzaki, Goro

    2015-12-01

    Although the BCG vaccine can prevent tuberculosis (TB) in infants, its ability to prevent adult pulmonary TB is reportedly limited. Therefore, development of a novel effective vaccine against pulmonary TB has become an international research priority. We have previously reported that intranasal vaccination of mice with a mycobacterial heparin-binding hemagglutinin adhesin (HBHA) plus mucosal adjuvant cholera toxin (CT) enhances production of IFN-γ and anti-HBHA antibody and suppresses extrapulmonary bacterial dissemination after intranasal infection with BCG. In the present study, the effects of intranasal HBHA + CT vaccine on murine pulmonary Mycobacterium tuberculosis (Mtb) infection were examined. Intranasal HBHA + CT vaccination alone failed to reduce the bacterial burden in the infected lung. However, a combination vaccine consisting of s.c. BCG priming and an intranasal HBHA + CT booster significantly enhanced protective immunity against pulmonary Mtb infection on day 14 compared with BCG vaccine alone. Further, it was found that intranasal HBHA + CT vaccine enhanced not only IFN-γ but also IL-17A production by HBHA-specific T cells in the lung after pulmonary Mtb infection. Therefore, this combination vaccine may be a good candidate for a new vaccine strategy against pulmonary TB. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  12. The anchorless adhesin Eap (extracellular adherence protein) from Staphylococcus aureus selectively recognizes extracellular matrix aggregates but binds promiscuously to monomeric matrix macromolecules.

    Science.gov (United States)

    Hansen, Uwe; Hussain, Muzaffar; Villone, Daniela; Herrmann, Mathias; Robenek, Horst; Peters, Georg; Sinha, Bhanu; Bruckner, Peter

    2006-05-01

    Besides a number of cell wall-anchored adhesins, the majority of Staphylococcus aureus strains produce anchorless, cell wall-associated proteins, such as Eap (extracellular adherence protein). Eap contains four to six tandem repeat (EAP)-domains. Eap mediates diverse biological functions, including adherence and immunomodulation, thus contributing to S. aureus pathogenesis. Eap binding to host macromolecules is unusually promiscuous and includes matrix or matricellular proteins as well as plasma proteins. The structural basis of this promiscuity is poorly understood. Here, we show that in spite of the preferential location of the binding epitopes within triple helical regions in some collagens there is a striking specificity of Eap binding to different collagen types. Collagen I, but not collagen II, is a binding substrate in monomolecular form. However, collagen I is virtually unrecognized by Eap when incorporated into banded fibrils. By contrast, microfibrils containing collagen VI as well as basement membrane-associated networks containing collagen IV, or aggregates containing fibronectin bound Eap as effectively as the monomeric proteins. Therefore, Eap-binding to extracellular matrix ligands is promiscuous at the molecular level but not indiscriminate with respect to supramolecular structures containing the same macromolecules. In addition, Eap bound to banded fibrils after their partial disintegration by matrix-degrading proteinases, including matrix metalloproteinase 1. Therefore, adherence to matrix suprastructures by S. aureus can be supported by inflammatory reactions.

  13. Vitronectin Binds to a Specific Stretch within the Head Region of Yersinia Adhesin A and Thereby Modulates Yersinia enterocolitica Host Interaction.

    Science.gov (United States)

    Mühlenkamp, Melanie C; Hallström, Teresia; Autenrieth, Ingo B; Bohn, Erwin; Linke, Dirk; Rinker, Janina; Riesbeck, Kristian; Singh, Birendra; Leo, Jack C; Hammerschmidt, Sven; Zipfel, Peter F; Schütz, Monika S

    2017-01-01

    Complement resistance is an important virulence trait of Yersinia enterocolitica (Ye). The predominant virulence factor expressed by Ye is Yersinia adhesin A (YadA), which enables bacterial attachment to host cells and extracellular matrix and additionally allows the acquisition of soluble serum factors. The serum glycoprotein vitronectin (Vn) acts as an inhibitory regulator of the terminal complement complex by inhibiting the lytic pore formation. Here, we show YadA-mediated direct interaction of Ye with Vn and investigated the role of this Vn binding during mouse infection in vivo. Using different Yersinia strains, we identified a short stretch in the YadA head domain of Ye O:9 E40, similar to the 'uptake region' of Y. pseudotuberculosis YPIII YadA, as crucial for efficient Vn binding. Using recombinant fragments of Vn, we found the C-terminal part of Vn, including heparin-binding domain 3, to be responsible for binding to YadA. Moreover, we found that Vn bound to the bacterial surface is still functionally active and thus inhibits C5b-9 formation. In a mouse infection model, we demonstrate that Vn reduces complement-mediated killing of Ye O:9 E40 and, thus, improved bacterial survival. Taken together, these findings show that YadA-mediated Vn binding influences Ye pathogenesis. © 2016 S. Karger AG, Basel.

  14. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy.

    Science.gov (United States)

    Tang, Wenxing; Bhatt, Avni; Smith, Adam N; Crowley, Paula J; Brady, L Jeannine; Long, Joanna R

    2016-02-01

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ~57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin.

  15. Streptococcus pneumoniae Cell-Wall-Localized Phosphoenolpyruvate Protein Phosphotransferase Can Function as an Adhesin: Identification of Its Host Target Molecules and Evaluation of Its Potential as a Vaccine.

    Directory of Open Access Journals (Sweden)

    Yaffa Mizrachi Nebenzahl

    Full Text Available In Streptococcus pneumonia, phosphoenolpyruvate protein phosphotransferase (PtsA is an intracellular protein of the monosaccharide phosphotransferase systems. Biochemical and immunostaining methods were applied to show that PtsA also localizes to the bacterial cell-wall. Thus, it was suspected that PtsA has functions other than its main cytoplasmic enzymatic role. Indeed, recombinant PtsA and anti-rPtsA antiserum were shown to inhibit adhesion of S. pneumoniae to cultured human lung adenocarcinoma A549 cells. Screening of a combinatorial peptide library expressed in a filamentous phage with rPtsA identified epitopes that were capable of inhibiting S. pneumoniae adhesion to A549 cells. The insert peptides in the phages were sequenced, and homologous sequences were found in human BMPER, multimerin1, protocadherin19, integrinβ4, epsin1 and collagen type VIIα1 proteins, all of which can be found in A549 cells except the latter. Six peptides, synthesized according to the homologous sequences in the human proteins, specifically bound rPtsA in the micromolar range and significantly inhibited pneumococcal adhesion in vitro to lung- and tracheal-derived cell lines. In addition, the tested peptides inhibited lung colonization after intranasal inoculation of mice with S. pneumoniae. Immunization with rPtsA protected the mice against a sublethal intranasal and a lethal intravenous pneumococcal challenge. In addition, mouse anti rPtsA antiserum reduced bacterial virulence in the intravenous inoculation mouse model. These findings showed that the surface-localized PtsA functions as an adhesin, PtsA binding peptides derived from its putative target molecules can be considered for future development of therapeutics, and rPtsA should be regarded as a candidate for vaccine development.

  16. Design

    DEFF Research Database (Denmark)

    Volf, Mette

    Design - proces & metode iBog®  er enestående i sit fokus på afmystificering og operationalisering af designprocessens flygtige og komplekse karakter. Udgivelsen går bag om designerens daglige arbejde og giver et indblik i den kreative skabelsesproces, som designeren er en del af. Udover et bredt...... indblik i designerens arbejdsmetoder og designparametre giver Design - proces & metode en række eksempler fra anerkendte designvirksomheder, der gør det muligt at komme helt tæt på designerens virkelighed....

  17. Design

    Science.gov (United States)

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  18. The knockdown of each component of the cysteine proteinase-adhesin complex of Entamoeba histolytica (EhCPADH) affects the expression of the other complex element as well as the in vitro and in vivo virulence.

    Science.gov (United States)

    Ocádiz-Ruiz, Ramón; Fonseca, Wendy; Linford, Alicia S; Yoshino, Timothy P; Orozco, Esther; Rodríguez, Mario A

    2016-01-01

    Entamoeba histolytica is the protozoan parasite causative of human amoebiasis, disease responsible for 40 000-100 000 deaths annually. The cysteine proteinase-adhesin complex of this parasite (EhCPADH) is a heterodimeric protein formed by a cysteine protease (EhCP112) and an adhesin (EhADH) that plays an important role in the cytopathic mechanism of this parasite. The coding genes for EhCP112 and EhADH are adjacent in the E. histolytica genome, suggesting that their expression may be co-regulated, but this hypothesis has not yet been confirmed. Here, we performed the knockdown of EhCP112 and EhADH using gene-specific short-hairpin RNAs (shRNA), and the effect of these knockdowns on the expression of both complex components as well as on the in vitro and in vivo virulence was analysed. Results showed that the knockdown of one of the EhCPADH components produced a simultaneous downregulation of the other protein. Accordingly, a concomitant reduction in the overall expression of the complex was observed. The downregulation of each component also produced a significant decrease in the in vitro and in vivo virulence of trophozoites. These results demonstrated that the expression of EhCP112 and EhADH is co-regulated and confirmed that the EhCPADH complex plays an important role in E. histolytica virulence.

  19. Bartonella henselae trimeric autotransporter adhesin BadA expression interferes with effector translocation by the VirB/D4 type IV secretion system.

    Science.gov (United States)

    Lu, Yun-Yueh; Franz, Bettina; Truttmann, Matthias C; Riess, Tanja; Gay-Fraret, Jérémie; Faustmann, Marco; Kempf, Volkhard A J; Dehio, Christoph

    2013-05-01

    The Gram-negative, zoonotic pathogen Bartonella henselae is the aetiological agent of cat scratch disease, bacillary angiomatosis and peliosis hepatis in humans. Two pathogenicity factors of B. henselae - each displaying multiple functions in host cell interaction - have been characterized in greater detail: the trimeric autotransporter Bartonella adhesin A (BadA) and the type IV secretion system VirB/D4 (VirB/D4 T4SS). BadA mediates, e.g. binding to fibronectin (Fn), adherence to endothelial cells (ECs) and secretion of vascular endothelial growth factor (VEGF). VirB/D4 translocates several Bartonella effector proteins (Beps) into the cytoplasm of infected ECs, resulting, e.g. in uptake of bacterial aggregates via the invasome structure, inhibition of apoptosis and activation of a proangiogenic phenotype. Despite this knowledge of the individual activities of BadA or VirB/D4 it is unknown whether these major virulence factors affect each other in their specific activities. In this study, expression and function of BadA and VirB/D4 were analysed in a variety of clinical B. henselae isolates. Data revealed that most isolates have lost expression of either BadA or VirB/D4 during in vitro passages. However, the phenotypic effects of coexpression of both virulence factors was studied in one clinical isolate that was found to stably coexpress BadA and VirB/D4, as well as by ectopic expression of BadA in a strain expressing VirB/D4 but not BadA. BadA, which forms a dense layer on the bacterial surface, negatively affected VirB/D4-dependent Bep translocation and invasome formation by likely preventing close contact between the bacterial cell envelope and the host cell membrane. In contrast, BadA-dependent Fn binding, adhesion to ECs and VEGF secretion were not affected by a functional VirB/D4 T4SS. The obtained data imply that the essential virulence factors BadA and VirB/D4 are likely differentially expressed during different stages of the infection cycle of

  20. Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Pettiway, Keon

    2017-01-01

    In this chapter, Ole B. Jensen takes a situational approach to mobilities to examine how ordinary life activities are structured by technology and design. Using “staging mobilities” as a theoretical approach, Jensen considers mobilities as overlapping, actions, interactions and decisions by desig...... by providing ideas about future research for investigating mobilities in situ as a kind of “staging,” which he notes is influenced by the “material turn” in social sciences....... with a brief description of how movement is studied within social sciences after the “mobilities turn” versus the idea of physical movement in transport geography and engineering. He then explains how “mobilities design” was derived from connections between traffic and architecture. Jensen concludes...

  1. Potential use of a recombinant replication-defective adenovirus vector carrying the C-terminal portion of the P97 adhesin protein as a vaccine against Mycoplasma hyopneumoniae in swine.

    Science.gov (United States)

    Okamba, Faust René; Arella, Maximilien; Music, Nedzad; Jia, Jian Jun; Gottschalk, Marcelo; Gagnon, Carl A

    2010-07-05

    Mycoplasma hyopneumoniae causes severe economic losses to the swine industry worldwide and the prevention of its related disease, enzootic porcine pneumonia, remains a challenge. The P97 adhesin protein of M. hyopneumoniae should be a good candidate for the development of a subunit vaccine because antibodies produced against P97 could prevent the adhesion of the pathogen to the respiratory epithelial cells in vitro. In the present study, a P97 recombinant replication-defective adenovirus (rAdP97c) subunit vaccine efficiency was evaluated in pigs. The rAdP97c vaccine was found to induce both strong P97 specific humoral and cellular immune responses. The rAdP97c vaccinated pigs developed a lower amount of macroscopic lung lesions (18.5 + or - 9.6%) compared to the unvaccinated and challenged animals (45.8 + or - 11.5%). rAdP97c vaccine reduced significantly the severity of inflammatory response and the amount of M. hyopneumoniae in the respiratory tract. Furthermore, the average daily weight gain was slightly improved in the rAdP97c vaccinated pigs (0.672 + or - 0.068 kg/day) compared to the unvaccinated and challenged animals (0.568 + or - 0.104 kg/day). A bacterin-based commercial vaccine (Suvaxyn MH-one) was more efficient to induce a protective immune response than rAdP97c even if it did not evoke a P97 specific immune response. These results suggest that immunodominant antigens other than P97 adhesin are also important in the induction of a protective immune response and should be taken into account in the future development of M. hyopneumoniae subunit vaccines. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. Identification and phenotypic characterization of a second collagen adhesin, Scm, and genome-based identification and analysis of 13 other predicted MSCRAMMs, including four distinct pilus loci, in Enterococcus faecium.

    Science.gov (United States)

    Sillanpää, Jouko; Nallapareddy, Sreedhar R; Prakash, Vittal P; Qin, Xiang; Höök, Magnus; Weinstock, George M; Murray, Barbara E

    2008-10-01

    Attention has recently been drawn to Enterococcus faecium because of an increasing number of nosocomial infections caused by this species and its resistance to multiple antibacterial agents. However, relatively little is known about the pathogenic determinants of this organism. We have previously identified a cell-wall-anchored collagen adhesin, Acm, produced by some isolates of E. faecium, and a secreted antigen, SagA, exhibiting broad-spectrum binding to extracellular matrix proteins. Here, we analysed the draft genome of strain TX0016 for potential microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Genome-based bioinformatics identified 22 predicted cell-wall-anchored E. faecium surface proteins (Fms), of which 15 (including Acm) had characteristics typical of MSCRAMMs, including predicted folding into a modular architecture with multiple immunoglobulin-like domains. Functional characterization of one [Fms10; redesignated second collagen adhesin of E. faecium (Scm)] revealed that recombinant Scm(65) (A- and B-domains) and Scm(36) (A-domain) bound to collagen type V efficiently in a concentration-dependent manner, bound considerably less to collagen type I and fibrinogen, and differed from Acm in their binding specificities to collagen types IV and V. Results from far-UV circular dichroism measurements of recombinant Scm(36) and of Acm(37) indicated that these proteins were rich in beta-sheets, supporting our folding predictions. Whole-cell ELISA and FACS analyses unambiguously demonstrated surface expression of Scm in most E. faecium isolates. Strikingly, 11 of the 15 predicted MSCRAMMs clustered in four loci, each with a class C sortase gene; nine of these showed similarity to Enterococcus faecalis Ebp pilus subunits and also contained motifs essential for pilus assembly. Antibodies against one of the predicted major pilus proteins, Fms9 (redesignated EbpC(fm)), detected a 'ladder' pattern of high-molecular-mass protein bands in a

  3. Novel Aggregative Adherence Fimbria Variant of Enteroaggregative Escherichia coli

    DEFF Research Database (Denmark)

    Jønsson, Rie; Struve, Carsten; Boisen, Nadia

    2015-01-01

    the stools of Danish adults with traveler’s diarrhea. We evaluated the presence of the aggregative adherence fimbriae (AAFs) by a multiplex PCR, targeting the four known major subunit variants as well as their usher-encoding genes. Almost one-half (49/118) of the clinical isolates did not possess any known...... AAF major fimbrial subunit, despite the presence of other AggR-related loci. Further investigation revealed the presence of an AAF-related gene encoding a yet-uncharacterized adhesin, termed agg5A. The sequence of the agg5DCBA gene cluster shared fimbrial accessory genes (usher, chaperone, and minor...

  4. Diversification of the Salmonella fimbriae: a model of macro- and microevolution.

    Directory of Open Access Journals (Sweden)

    Min Yue

    Full Text Available Bacteria of the genus Salmonella comprise a large and evolutionary related population of zoonotic pathogens that can infect mammals, including humans and domestic animals, birds, reptiles and amphibians. Salmonella carries a plethora of virulence genes, including fimbrial adhesins, some of them known to participate in mammalian or avian host colonization. Each type of fimbria has its structural subunit and biogenesis genes encoded by one fimbrial gene cluster (FGC. The accumulation of new genomic information offered a timely opportunity to better evaluate the number and types of FGCs in the Salmonella pangenome, to test the use of current classifications based on phylogeny, and to infer potential correlations between FGC evolution in various Salmonella serovars and host niches. This study focused on the FGCs of the currently deciphered 90 genomes and 60 plasmids of Salmonella. The analysis highlighted a fimbriome consisting of 35 different FGCs, of which 16 were new, each strain carrying between 5 and 14 FGCs. The Salmonella fimbriome was extremely diverse with FGC representatives in 8 out of 9 previously categorized fimbrial clades and subclades. Phylogenetic analysis of Salmonella suggested macroevolutionary shifts detectable by extensive FGC deletion and acquisition. In addition, microevolutionary drifts were best depicted by the high level of allelic variation in predicted or known adhesins, such as the type 1 fimbrial adhesin FimH for which 67 different natural alleles were identified in S. enterica subsp. I. Together with strain-specific collections of FGCs, allelic variation among adhesins attested to the pathoadaptive evolution of Salmonella towards specific hosts and tissues, potentially modulating host range, strain virulence, disease progression, and transmission efficiency. Further understanding of how each Salmonella strain utilizes its panel of FGCs and specific adhesin alleles for survival and infection will support the

  5. Diversification of the Salmonella Fimbriae: A Model of Macro- and Microevolution

    Science.gov (United States)

    Yue, Min; Rankin, Shelley C.; Blanchet, Ryan T.; Nulton, James D.; Edwards, Robert A.; Schifferli, Dieter M.

    2012-01-01

    Bacteria of the genus Salmonella comprise a large and evolutionary related population of zoonotic pathogens that can infect mammals, including humans and domestic animals, birds, reptiles and amphibians. Salmonella carries a plethora of virulence genes, including fimbrial adhesins, some of them known to participate in mammalian or avian host colonization. Each type of fimbria has its structural subunit and biogenesis genes encoded by one fimbrial gene cluster (FGC). The accumulation of new genomic information offered a timely opportunity to better evaluate the number and types of FGCs in the Salmonella pangenome, to test the use of current classifications based on phylogeny, and to infer potential correlations between FGC evolution in various Salmonella serovars and host niches. This study focused on the FGCs of the currently deciphered 90 genomes and 60 plasmids of Salmonella. The analysis highlighted a fimbriome consisting of 35 different FGCs, of which 16 were new, each strain carrying between 5 and 14 FGCs. The Salmonella fimbriome was extremely diverse with FGC representatives in 8 out of 9 previously categorized fimbrial clades and subclades. Phylogenetic analysis of Salmonella suggested macroevolutionary shifts detectable by extensive FGC deletion and acquisition. In addition, microevolutionary drifts were best depicted by the high level of allelic variation in predicted or known adhesins, such as the type 1 fimbrial adhesin FimH for which 67 different natural alleles were identified in S. enterica subsp. I. Together with strain-specific collections of FGCs, allelic variation among adhesins attested to the pathoadaptive evolution of Salmonella towards specific hosts and tissues, potentially modulating host range, strain virulence, disease progression, and transmission efficiency. Further understanding of how each Salmonella strain utilizes its panel of FGCs and specific adhesin alleles for survival and infection will support the development of new approaches

  6. Construction of improved temperature-sensitive and mobilizable vectors and their use for constructing mutations in the adhesin-encoding acm gene of poorly transformable clinical Enterococcus faecium strains.

    Science.gov (United States)

    Nallapareddy, Sreedhar R; Singh, Kavindra V; Murray, Barbara E

    2006-01-01

    Inactivation by allelic exchange in clinical isolates of the emerging nosocomial pathogen Enterococcus faecium has been hindered by lack of efficient tools, and, in this study, transformation of clinical isolates was found to be particularly problematic. For this reason, a vector for allelic replacement (pTEX5500ts) was constructed that includes (i) the pWV01-based gram-positive repAts replication region, which is known to confer a high degree of temperature intolerance, (ii) Escherichia coli oriR from pUC18, (iii) two extended multiple-cloning sites located upstream and downstream of one of the marker genes for efficient cloning of flanking regions for double-crossover mutagenesis, (iv) transcriptional terminator sites to terminate undesired readthrough, and (v) a synthetic extended promoter region containing the cat gene for allelic exchange and a high-level gentamicin resistance gene, aph(2'')-Id, to distinguish double-crossover recombination, both of which are functional in gram-positive and gram-negative backgrounds. To demonstrate the functionality of this vector, the vector was used to construct an acm (encoding an adhesin to collagen from E. faecium) deletion mutant of a poorly transformable multidrug-resistant E. faecium endocarditis isolate, TX0082. The acm-deleted strain, TX6051 (TX0082Deltaacm), was shown to lack Acm on its surface, which resulted in the abolishment of the collagen adherence phenotype observed in TX0082. A mobilizable derivative (pTEX5501ts) that contains oriT of Tn916 to facilitate conjugative transfer from the transformable E. faecalis strain JH2Sm::Tn916 to E. faecium was also constructed. Using this vector, the acm gene of a nonelectroporable E. faecium wound isolate was successfully interrupted. Thus, pTEX5500ts and its mobilizable derivative demonstrated their roles as important tools by helping to create the first reported allelic replacement in E. faecium; the constructed this acm deletion mutant will be useful for assessing the

  7. Surfactant protein A (SP-A)-mediated clearance of Staphylococcus aureus involves binding of SP-A to the staphylococcal adhesin eap and the macrophage receptors SP-A receptor 210 and scavenger receptor class A.

    Science.gov (United States)

    Sever-Chroneos, Zvjezdana; Krupa, Agnieszka; Davis, Jeremy; Hasan, Misbah; Yang, Ching-Hui; Szeliga, Jacek; Herrmann, Mathias; Hussain, Muzafar; Geisbrecht, Brian V; Kobzik, Lester; Chroneos, Zissis C

    2011-02-11

    Staphylococcus aureus causes life-threatening pneumonia in hospitals and deadly superinfection during viral influenza. The current study investigated the role of surfactant protein A (SP-A) in opsonization and clearance of S. aureus. Previous studies showed that SP-A mediates phagocytosis via the SP-A receptor 210 (SP-R210). Here, we show that SP-R210 mediates binding and control of SP-A-opsonized S. aureus by macrophages. We determined that SP-A binds S. aureus through the extracellular adhesin Eap. Consequently, SP-A enhanced macrophage uptake of Eap-expressing (Eap(+)) but not Eap-deficient (Eap(-)) S. aureus. In a reciprocal fashion, SP-A failed to enhance uptake of Eap(+) S. aureus in peritoneal Raw264.7 macrophages with a dominant negative mutation (SP-R210(DN)) blocking surface expression of SP-R210. Accordingly, WT mice cleared infection with Eap(+) but succumbed to sublethal infection with Eap- S. aureus. However, SP-R210(DN) cells compensated by increasing non-opsonic phagocytosis of Eap(+) S. aureus via the scavenger receptor scavenger receptor class A (SR-A), while non-opsonic uptake of Eap(-) S. aureus was impaired. Macrophages express two isoforms: SP-R210(L) and SP-R210(S). The results show that WT alveolar macrophages are distinguished by expression of SP-R210(L), whereas SR-A(-/-) alveolar macrophages are deficient in SP-R210(L) expressing only SP-R210(S). Accordingly, SR-A(-/-) mice were highly susceptible to both Eap(+) and Eap(-) S. aureus. The lungs of susceptible mice generated abnormal inflammatory responses that were associated with impaired killing and persistence of S. aureus infection in the lung. In conclusion, alveolar macrophage SP-R210(L) mediates recognition and killing of SP-A-opsonized S. aureus in vivo, coordinating inflammatory responses and resolution of S. aureus pneumonia through interaction with SR-A.

  8. Role of type 1 and type 3 fimbriae in Klebsiella pneumoniae biofilm formation

    DEFF Research Database (Denmark)

    Schroll, C.; Barken, Kim Bundvig; Krogfelt, K.A.

    2010-01-01

    nosocomial infections. Most clinical K. pneumoniae isolates express two types of fimbrial adhesins, type 1 fimbriae and type 3 fimbriae. In this study, we characterized the role of type 1 and type 3 fimbriae in K. pneumoniae biofilm formation. Results: Isogenic fimbriae mutants of the clinical K. pneumoniae...... of planktonic cells. Type 1 fimbriae did not influence biofilm formation and the expression of type 1 fimbriae was found to be down-regulated in biofilm forming cells. In contrast, expression of type 3 fimbriae was found to strongly promote biofilm formation. Conclusion: By use of well defined isogenic mutants...... we found that type 3 fimbriae, but not type 1 fimbriae, strongly promote biofilm formation in K. pneumoniae C3091. As the vast majority of clinical K. pneumoniae isolates express type 3 fimbriae, this fimbrial adhesin may play a significant role in development of catheter associated K. pneumoniae...

  9. YadA, the multifaceted Yersinia adhesin.

    Science.gov (United States)

    El Tahir, Y; Skurnik, M

    2001-08-01

    The adhesion protein YadA is encoded by the yadA gene located in the 70-kb virulence plasmid of Yersinia (pYV) that is common to the pathogenic Yersinia species (Y. pestis, Y. pseudotuberculosis and Y. enterocolitica). YadA is a virulence factor of Y. enterocolitica, however, YadA seems to be dispensable for the virulence of Y. pseudotuberculosis, and in wild-type Y. pestis the yadA gene has a frameshift mutation silencing the gene. Expression of the Y. pseudotuberculosis YadA in Y. pestis reduces its virulence. YadA is a homotrimer of ca. 45-kDa subunits that are anchored to the outer membrane via their C-termini, while their N-termini form a globular head on top of a stalk; the 'lollipop'-shaped YadA structure covers the entire bacterial surface giving it hydrophobic properties. The yadA gene expression is induced at 37 degrees C by the temperature-dependent transcriptional activator LcrF. YadA is a multifaceted protein as revealed by its different biological properties. YadA+ bacteria bind to collagens, laminin, fibronectin, intestinal submucosa, mucus, and to hydrophobic surfaces like polystyrene. YadA+ bacteria autoagglutinate in stationary culture and also specifically agglutinate guinea pig red blood cells. YadA is also a potent serum resistance factor as it inhibits the classical pathway of complement. As invasin, it mediates low rate invasion to tissue culture cells. In a rat model of reactive arthritis YadA and specifically YadA-mediated collagen binding is necessary for Y. enterocolitica to induce the disease. Despite of this wealth of information or perhaps because of it, the in vivo role of YadA during infection remains still largely unresolved.

  10. Characterization of Helicobacter pylori adhesin thiol peroxidase ...

    Indian Academy of Sciences (India)

    Prakash

    H. pylori induces a strong inflammatory response ... 2003). Prx inactivation has also been observed in plants (Kitajima 2008) and yeast .... 2.1 Expression and purification of wild-type and mutant. HpTpx ... density (OD)600 of 0.6–0.8 and induced by 0.5 mM isopropyl ... Far-UV circular dichroism (CD) spectroscopy was used.

  11. Contribution of trimeric autotransporter C-terminal domains of oligomeric coiled-coil adhesin (Oca) family members YadA, UspA1, EibA, and Hia to translocation of the YadA passenger domain and virulence of Yersinia enterocolitica.

    Science.gov (United States)

    Ackermann, Nikolaus; Tiller, Maximilian; Anding, Gisela; Roggenkamp, Andreas; Heesemann, Jürgen

    2008-07-01

    The Oca family is a novel class of autotransporter-adhesins with highest structural similarity in their C-terminal transmembrane region, which supposedly builds a beta-barrel pore in the outer membrane (OM). The prototype of the Oca family is YadA, an adhesin of Yersinia enterocolitica and Yersinia pseudotuberculosis. YadA forms a homotrimeric lollipop-like structure on the bacterial surface. The C-terminal regions of three YadA monomers form a barrel in the OM and translocate the trimeric N-terminal passenger domain, consisting of stalk, neck, and head region to the exterior. To elucidate the structural and functional role of the C-terminal translocator domain (TLD) and to assess its promiscuous capability with respect to transport of related passenger domains, we constructed chimeric YadA proteins, which consist of the N-terminal YadA passenger domain and C-terminal TLDs of Oca family members UspA1 (Moraxella catarrhalis), EibA (Escherichia coli), and Hia (Haemophilus influenzae). These constructs were expressed in Y. enterocolitica and compared for OM localization, surface exposure, oligomerization, adhesion properties, serum resistance, and mouse virulence. We demonstrate that all chimeric YadA proteins translocated the YadA passenger domain across the OM. Y. enterocolitica strains producing YadA chimeras or wild-type YadA showed comparable binding to collagen and epithelial cells. However, strains producing YadA chimeras were attenuated in serum resistance and mouse virulence. These results demonstrate for the first time that TLDs of Oca proteins of different origin are efficient translocators of the YadA passenger domain and that the cognate TLD of YadA is essential for bacterial survival in human serum and mouse virulence.

  12. Design Methodology - Design Synthesis

    DEFF Research Database (Denmark)

    Andreasen, Mogens Myrup

    2003-01-01

    Design Methodology is part of our practice and our knowledge about designing, and it has been strongly supported by the establishing and work of a design research community. The aim of this article is to broaden the reader¿s view of designing and Design Methodology. This is done by sketching...... the development of Design Methodology through time and sketching some important approaches and methods. The development is mainly forced by changing industrial condition, by the growth of IT support for designing, but also by the growth of insight into designing created by design researchers.......ABSTRACT Design Methodology shall be seen as our understanding of how to design; it is an early (emerging late 60ies) and original articulation of teachable and learnable methodics. The insight is based upon two sources: the nature of the designed artefacts and the nature of human designing. Today...

  13. Designing Material Materialising Design

    DEFF Research Database (Denmark)

    Nicholas, Paul

    2013-01-01

    Designing Material Materialising Design documents five projects developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts, School of Architecture. These projects explore the idea that new designed materials might require new design methods....... Focusing on fibre reinforced composites, this book sustains an exploration into the design and making of elastically tailored architectural structures that rely on the use of computational design to predict sensitive interdependencies between geometry and behaviour. Developing novel concepts...

  14. Designing Communication Design

    DEFF Research Database (Denmark)

    Løvlie, Anders Sundnes

    2016-01-01

    Innovating in the field of new media genres requires methods for producing designs that can succeed in being disseminated and used outside of design research labs. This article uses the author's experiences with the development of university courses in communication design to address the research...... question: How can we design courses to give students the competencies they need to work as designers of new media? Based on existing approaches from UX design and other fields, I present a model that has demonstrated its usefulness in the development of commercial products and services. The model...

  15. Virulence factors of Escherichia coli in relation to the importance of vaccination in pigs

    Directory of Open Access Journals (Sweden)

    Daniele Araujo Pereira

    2016-08-01

    Full Text Available ABSTRACT: Enterotoxigenic Escherichia coli (ETEC is the major cause of diarrhea in newborn and weaned pigs. Bacteria adhesion to the host cell is considered a specific phenomenon among fimbrial and non-fimbrial adhesins with their respective receptors on enterocytes. Enteric disorders are related with the fimbriae F4 (K88, F5 (K99, F6 (987P, F41, and F18. In addition to ETEC, another category of E. coli , porcine pathogenic E. coli (PEPEC,can cause diarrhea in pigs; it produces the porcine attaching and effacing-associated (Paa adhesin in, which is capable to cause a typical lesion known as an attaching and effacing (A/E lesion. Immunization of sows with adhesin is important to stimulate the production of antibodies and their subsequent transfer to piglets through colostrum. The aim of this paper is to illustrate the main impacts of enteric diseases caused by E. coli in swine production and to highlight the importance of continuing research on this bacterium to improve disease prevention through vaccination.

  16. Prompting Designers to Design

    DEFF Research Database (Denmark)

    Ahmed, Saeema

    2006-01-01

    Recent research suggest that engineering designers need assistance to understand what information is relevant for their particular design problem. They require guidance in formulating their queries and also to understand what information is relevant for them. This paper presents an approach to pr...

  17. Winged design; Befluegeltes Design

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Tilman

    2013-10-15

    Today the wind rotor blades are about 80 meter long. To keep them light and transportable designers and material scientists come up with a number of ideas. Will the carbon fiber prevail against the glass fiber? [German] Ueber 80 Meter messen die laengsten Rotorblaetter heute. Um sie leicht und transportfaehig zu halten, lassen sich Designer und Materialforscher einiges einfallen. Wird sich die Kohlefaser gegen die Glasfaser durchsetzen?.

  18. Dansk Design

    DEFF Research Database (Denmark)

    Dickson, Thomas

    Indhold: Hvad er design?; Hvor kommer dansk design fra?; Produktdesign; Tekstil- og tøjdesign; Design af møbler og boligindretning; Bygningen og design; Arbejdets design; Transportdesign; Offentligt design; Grafisk design; Nye tider og en ny slags design...

  19. Novel Zn2+-chelating peptides selected from a fimbria-displayed random peptide library

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Schembri, Mark; Klemm, Per

    2001-01-01

    The display of peptide sequences on the surface of bacteria is a technology that offers exciting applications in biotechnology and medical research. Type 1 fimbriae are surface organelles of Escherichia coli which mediate D-mannose-sensitive binding to different host surfaces by virtue of the Fim......H adhesin. FimH is a component of the fimbrial organelle that can accommodate and display a diverse range of peptide sequences on the E. coli cell surface. In this study we have constructed a random peptide library in FimH. The library, consisting of similar to 40 million individual clones, was screened...

  20. FimH-mediated autoaggregation of Escherichia coli

    DEFF Research Database (Denmark)

    Schembri, Mark; Christiansen, G.; Klemm, Per

    2001-01-01

    Autoaggregation is a phenomenon thought to contribute to colonization of mammalian hosts by pathogenic bacteria. Type 1 fimbriae are surface organelles of Escherichia coli that mediate D-mannose-sensitive binding to various host surfaces. This binding is conferred by the minor fimbrial component...... FimH. In this study, we have used random mutagenesis to identify variants of the FimH adhesin that confer the ability of E. coli to autoaggregate and settle from liquid cultures. Three separate autoaggregating clones were identified, all of which contained multiple amino acid changes located within...

  1. VLSI design

    CERN Document Server

    Chandrasetty, Vikram Arkalgud

    2011-01-01

    This book provides insight into the practical design of VLSI circuits. It is aimed at novice VLSI designers and other enthusiasts who would like to understand VLSI design flows. Coverage includes key concepts in CMOS digital design, design of DSP and communication blocks on FPGAs, ASIC front end and physical design, and analog and mixed signal design. The approach is designed to focus on practical implementation of key elements of the VLSI design process, in order to make the topic accessible to novices. The design concepts are demonstrated using software from Mathworks, Xilinx, Mentor Graphic

  2. Design Anthropology in Participatory Design

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Kjærsgaard, Mette Gislev

    2015-01-01

    This focus section explores the opportunities of design anthropology in participatory design as an approach to research and design in an increasingly global and digital world. Traditionally, ethnography has been used in Participatory design to research real-life contexts and challenges, and as ways...... opportunities of using design anthropology as a holistic and critical approach to addressing societal challenges and change, and a way for anthropologists and designers to engage in participatory research and design that extend beyond the empirical....

  3. Design Anthropology in Participatory Design

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Gislev Kjærsgaard, Mette

    2014-01-01

    In this workshop we explore the opportunities of ethnography and design anthropology in Participatory Design (PD) as an approach to design in an increasingly global and digital world. Traditionally, ethnography has been used in PD to research real-life contexts and challenges, and as ways...... opportunities of using design anthropology as a holistic and critical approach to societal challenges, and a way for anthropologists and designers to engage in design that extends beyond the empirical....

  4. Evidensbaseret design

    DEFF Research Database (Denmark)

    Pagh, Jesper

    2013-01-01

    Debatindlæg om evidensbaseret design, som argumenterer for at det dels er en gammeldags, modernistisk tilgang til design, dels ikke baserer sig på evidens.......Debatindlæg om evidensbaseret design, som argumenterer for at det dels er en gammeldags, modernistisk tilgang til design, dels ikke baserer sig på evidens....

  5. FPGA design

    CERN Document Server

    Simpson, Philip

    2010-01-01

    This book describes best practices for successful FPGA design. It is the result of the author's meetings with hundreds of customers on the challenges facing each of their FPGA design teams. By gaining an understanding into their design environments, processes, what works and what does not work, key areas of concern in implementing system designs have been identified and a recommended design methodology to overcome these challenges has been developed. This book's content has a strong focus on design teams that are spread across sites. The goal being to increase the productivity of FPGA design t

  6. Design Games

    DEFF Research Database (Denmark)

    Johansson, Martin Wetterstrand

    2007-01-01

    In this paper design games are discussed as an approach to managing design sessions. The focus is on the collaborative design session and more particular on how to set up the collaboration and reinsure progress. Design games have the advantage of framing the collaborative assignment at hand....... Experiments can be set up to explore possible futures and design games has the qualities of elegantly focus the work at the same time as it lessens the burden for the process facilitator. The present paper goes into detail about how design games can be set up to facilitate collaboration and how the design...

  7. Design What?%

    DEFF Research Database (Denmark)

    Engholm, Ida

    2017-01-01

    processes, which require specific development methods across a wide range of disciplines, from industrial design over graphic communication to service and digital design and strategic corporate development. The book addresses both established methods and recent research in design processes at leading design...... idea to the end-result. The goal for this graphic non-fiction project is to document and present both historical and current developments in design methodology, from the early attempts at documenting procedures for design process management at the Bauhaus School in the 1920s to contemporary design...

  8. VLSI design

    CERN Document Server

    Basu, D K

    2014-01-01

    Very Large Scale Integrated Circuits (VLSI) design has moved from costly curiosity to an everyday necessity, especially with the proliferated applications of embedded computing devices in communications, entertainment and household gadgets. As a result, more and more knowledge on various aspects of VLSI design technologies is becoming a necessity for the engineering/technology students of various disciplines. With this goal in mind the course material of this book has been designed to cover the various fundamental aspects of VLSI design, like Categorization and comparison between various technologies used for VLSI design Basic fabrication processes involved in VLSI design Design of MOS, CMOS and Bi CMOS circuits used in VLSI Structured design of VLSI Introduction to VHDL for VLSI design Automated design for placement and routing of VLSI systems VLSI testing and testability The various topics of the book have been discussed lucidly with analysis, when required, examples, figures and adequate analytical and the...

  9. Design Accountability

    DEFF Research Database (Denmark)

    Koskinen, Ilpo; Krogh, Peter

    2015-01-01

    When design research builds on design practice, it may contribute to both theory and practice of design in ways richer than research that treats design as a topic. Such research, however, faces several tensions that it has to negotiate successfully in order not to lose its character as research....... This paper looks at constructive design research which takes the entanglement of theory and practice as its hallmark, and uses it as a test case in exploring how design researchers can work with theory, methodology, and practice without losing their identity as design researchers. The crux of practice based...... design research is that where classical research is interested in singling out a particular aspect and exploring it in depth, design practice is characterized by balancing numerous concerns in a heterogenous and occasionally paradoxical product. It is on this basis the notion of design accountability...

  10. Novel roles for the AIDA adhesin from diarrheagenic Escherichia coli:

    DEFF Research Database (Denmark)

    Sherlock, Orla; Schembri, Mark; Reisner, A.

    2004-01-01

    Diarrhea-causing Escherichia coli strains are responsible for numerous cases of gastrointestinal disease and constitute a serious health problem throughout the world. The ability to recognize and attach to host intestinal surfaces is an essential step in the pathogenesis of such strains. AIDA...... binds to mammalian cells. Here, we show that AIDA possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrate that intercellular AIDA-AIDA interaction is responsible for bacterial autoaggregation. Interestingly, AIDA-expressing cells can interact...

  11. Characterization of three novel adhesins of Leptospira interrogans.

    Science.gov (United States)

    Siqueira, Gabriela H; Atzingen, Marina V; Alves, Ivy J; de Morais, Zenaide M; Vasconcellos, Silvio A; Nascimento, Ana L T O

    2013-12-01

    We report cloning, expression, purification, and characterization of three predicted leptospiral membrane proteins (LIC11360, LIC11009, and LIC11975). In silico analysis and proteinase K accessibility data suggest that these proteins might be surface exposed. We show that proteins encoded by LIC11360, LIC11009 and LIC11975 genes interact with laminin in a dose-dependent and saturable manner. The proteins are referred to as leptospiral surface adhesions 23, 26, and 36 (Lsa23, Lsa26, and Lsa36), respectively. These proteins also bind plasminogen and generate active plasmin. Attachment of Lsa23 and Lsa36 to fibronectin occurs through the involvement of the 30-kDa and 70-kDa heparin-binding domains of the ligand. Dose-dependent, specific-binding of Lsa23 to the complement regulator C4BP and to a lesser extent, to factor H, suggests that this protein may interfere with the complement cascade pathways. Leptospira spp. may use these interactions as possible mechanisms during the establishment of infection.

  12. RIFINs are adhesins implicated in severe Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Goel, Suchi; Palmkvist, Mia; Moll, Kirsten

    2015-01-01

    Rosetting is a virulent Plasmodium falciparum phenomenon associated with severe malaria. Here we demonstrate that P. falciparum–encoded repetitive interspersed families of polypeptides (RIFINs) are expressed on the surface of infected red blood cells (iRBCs), where they bind to RBCs—preferentiall......Rosetting is a virulent Plasmodium falciparum phenomenon associated with severe malaria. Here we demonstrate that P. falciparum–encoded repetitive interspersed families of polypeptides (RIFINs) are expressed on the surface of infected red blood cells (iRBCs), where they bind to RBCs......—preferentially of blood group A—to form large rosettes and mediate microvascular binding of iRBCs. We suggest that RIFINs have a fundamental role in the development of severe malaria and thereby contribute to the varying global distribution of ABO blood groups in the human population....

  13. Mechanical design

    CERN Document Server

    Risitano, Antonino

    2011-01-01

    METHODOLOGICAL STATEMENT OF ENGINEERING DESIGNApproaches to product design and developmentMechanical design and environmental requirementsPROPERTIES OF ENGINEERING MATERIALSMaterials for mechanical designCharacterization of metalsStress conditionsFatigue of materialsOptimum material selection in mechanical designDESIGN OF MECHANICAL COMPONENTS AND SYSTEMSFailure theoriesHertz theoryLubrificationShafts and bearingsSplines and keysSpringsFlexible machine elementsSpur gearsPress and shrink fitsPressure tubesCouplingsClutchesBrakes

  14. Memory design

    DEFF Research Database (Denmark)

    Tanderup, Sisse

    by cultural forms, often specifically by the concept of memory in philosophy, sociology and psychology, while Danish design traditionally has been focusing on form and function with frequent references to the forms of nature. Alessi's motivation for investigating the concept of memory is that it adds......Mind and Matter - Nordik 2009 Conference for Art Historians Design Matters Contributed Memory design BACKGROUND My research concerns the use of memory categories in the designs by the companies Alessi and Georg Jensen. When Alessi's designers create their products, they are usually inspired...... a cultural dimension to the design objects, enabling the objects to make an identity-forming impact. Whether or not the concept of memory plays a significant role in Danish design has not yet been elucidated fully. TERMINOLOGY The concept of "memory design" refers to the idea that design carries...

  15. Business design or Creative design

    DEFF Research Database (Denmark)

    Sørensen, Suna; Lassen, Astrid Heidemann; Nielsen, Louise Møller

    2008-01-01

    Business design is about turning good ideas into future business, but it requires a great entrepreneurial opportunity to be exploited via a valid strategic and organizational design. The literature says much about how entrepreneurs design strategies and organizations, but how do they design...

  16. Designing Interfaces

    CERN Document Server

    Tidwell, Jenifer

    2010-01-01

    Despite all of the UI toolkits available today, it's still not easy to design good application interfaces. This bestselling book is one of the few reliable sources to help you navigate through the maze of design options. By capturing UI best practices and reusable ideas as design patterns, Designing Interfaces provides solutions to common design problems that you can tailor to the situation at hand. This updated edition includes patterns for mobile apps and social media, as well as web applications and desktop software. Each pattern contains full-color examples and practical design advice th

  17. Design Anthropology

    DEFF Research Database (Denmark)

    Gunn, Wendy

    Design anthropology is a call for a different way of involving anthropology and participatory observation within practices of designing technologies, services, policies and infrastructure that does not aim towards changing human behavior. Here design is considered the process and not the object...... of inquiry. The paper presents a short history of design anthropology, its theoretical underpinnings and methodologies. Theoretically, the emerging field is influenced by processual, critical and action orientated approaches in anthropology. I argue that by combining anthropological methodology and knowledge...... with the future orientated imaginative praxis of design skill and collaborative design processes, anthropology and design could learn from each other. I conclude by referring to what theories, methods, and approaches are in use by practitioners of design anthropology....

  18. Danish design

    DEFF Research Database (Denmark)

    Dickson, Thomas

    2001-01-01

    Hvordan dansk design bliver innovativt og verdensberømt igen som i storhedstiden i 1950- og 60'erne......Hvordan dansk design bliver innovativt og verdensberømt igen som i storhedstiden i 1950- og 60'erne...

  19. Designing motivation

    DEFF Research Database (Denmark)

    How can products be designed to change our habits for the better? What is some of the leading research that designers can draw on to create new systems that motivate people towards healthier behaviour? Designing Motivation is an edited collection of ‘industrialist cheat sheets’: 22 single......-page summaries of research articles relating to technology design, motivation, and behaviour change. Ranging across the fields of economics, sociology, design research and behavioural science, each summary draws out the design implications of the research. It is intended as a resource for designers who...... are grappling with how to create motivating products, and as a primer for students who want a brief introduction to some of the relevant theories, findings and design interventions in these fields. The editor's introduction raises a number of issues encountered when we try to apply behavioural research...

  20. Research Design

    DEFF Research Database (Denmark)

    2019-01-01

    Gunnar Scott Reinbacher (editor) Antology.  Research Design : Validation in Social Sciences. Gunnar Scott Reinbacher: Introduction. Research design and validity. 15p Ole Riis: Creative Research design. 16 p Lennart Nørreklit: Validity in Research Design. 24p Gitte Sommer Harrits: Praxeological...... Scott Reinbacher: Multidisciplinary Research Designs in Problem Based Research. The case of an european project on chronical diseases, the Tandem project (Training Alternmative Networking Skills in Diabetes Management). 15p Niels Nørgaard Kristensen: A qualitative bottom up approach to post modern...... knowledge: An integrated strategy for combining "explaining" and "understanding". 22p Heidi Houlberg Salomonsen & Viola Burau: Comparative research designs. 40p Rasmus Antoft & Heidi Houlberg Salomonsen: Studying organizations by a Pragmatic Research Design: the case of qualitative case study  designs. 31p...

  1. Repository design

    Energy Technology Data Exchange (ETDEWEB)

    John, C M

    1982-01-01

    Various technical issues of radioactive waste design are addressed in this paper. Two approaches to repository design considered herein are: (1) design to minimize the disturbance of the hot rock; and (2) designs that intentionally modify the hot rock to insure better containment of the wastes. The latter designs range from construction of a highly impermeable barrier around a spherical cavern to creating a matrix of tunnels and boreholes to form a cage within which the hydraulic pressure is nearly constant. Examples of these design alternatives are described in some detail. It is concluded that proposed designs for repositories illustrate that performance criteria considered acceptable for such facilities can be met by appropriate site selection and repository engineering. With these technically feasible design concepts, it is also felt that socioeconomic and institutional issues can be better resolved. (BLM)

  2. Breakwater design

    OpenAIRE

    Verhagen, H.J.; van den Bos, J.P.

    2017-01-01

    For this book we have deliberately chosen that the text should follow a more or less logical design procedure for breakwaters. It follows the required design steps from the system level down to the individual crosssection level, and in time from conceptual design to construction. This systematic approach starts at the functional description of breakwaters, system analysis including side-effects and derivation of boundary conditions and continues to the actual design, first of the main armour ...

  3. Design typology and design organisation

    DEFF Research Database (Denmark)

    Andreasen, Mogens Myrup; Wognum, N.; McAloone, Timothy Charles

    2002-01-01

    research society has recognised normative procedural models of designing as being a reasonable answer to the question: How do designing proceed? The reasoning behind the models, from which the design methodology model by [Pahl & Beitz 1995], may be seen as a characteristic one, was a mix of human problem......The idea of focusing upon the creation of a design typology was articulated by [Andreasen & Wognum 2000] and detailed by [Andreasen & Wognum 2001]. The aim was to propose a typology, which could serve as identification of design types and design research contributions. For a long period the design...... solving-, design management-, and artefact nature-reasoning. Critique has been raised to that type of models as being neither explanatory nor instructive. If we accept these models as merely being pragmatically "stepping-stone" explanations of what happens during designing, it is interesting to observe...

  4. Design Processes

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2009-01-01

    Inspiration for most research and optimisations on design processes still seem to focus within the narrow field of the traditional design practise. The focus in this study turns to associated businesses of the design professions in order to learn from their development processes. Through interviews...... and emerging production methods....

  5. Radiopharmacy design

    International Nuclear Information System (INIS)

    Lazarus, C.R.

    1985-01-01

    The factors which should be considered when designing a radiopharmacy are examined. These include the levels and types of radioactivity and the functions, location, size and layout of the radiopharmacy. Aspects of the design process including environmental cleanliness in enclosed spaces and microbiological safety cabinets are also discussed. Finally the current publications available on recommendations and guidelines for radiopharmacy designs are briefly reviewed. (UK)

  6. Breakwater design

    NARCIS (Netherlands)

    Verhagen, H.J.; van den Bos, J.P.

    For this book we have deliberately chosen that the text should follow a more or less logical design procedure for breakwaters. It follows the required design steps from the system level down to the individual crosssection level, and in time from conceptual design to construction. This systematic

  7. Design Aspects

    International Nuclear Information System (INIS)

    Hillary, J.J.

    1974-01-01

    Summarizing part of a seminar on iodide filter testing the author classifies the design information on iodine filters which was presented at the meeting in terms of design requirements - species to be trapped sorption materials and engineering factors -, design evaluation, applications and operational experience

  8. Synergy between type 1 fimbriae expression and C3 opsonisation increases internalisation of E. coli by human tubular epithelial cells.

    Science.gov (United States)

    Li, Ke; Zhou, Wuding; Hong, Yuzhi; Sacks, Steven H; Sheerin, Neil S

    2009-03-31

    Bacterial infection of the urinary tract is a common clinical problem with E. coli being the most common urinary pathogen. Bacterial uptake into epithelial cells is increasingly recognised as an important feature of infection. Bacterial virulence factors, especially fimbrial adhesins, have been conclusively shown to promote host cell invasion. Our recent study reported that C3 opsonisation markedly increases the ability of E. coli strain J96 to internalise into human proximal tubular epithelial cells via CD46, a complement regulatory protein expressed on host cell membrane. In this study, we further assessed whether C3-dependent internalisation by human tubular epithelial cells is a general feature of uropathogenic E. coli and investigated features of the bacterial phenotype that may account for any heterogeneity. In 31 clinical isolates of E. coli tested, C3-dependent internalisation was evident in 10 isolates. Type 1 fimbriae mediated-binding is essential for C3-dependent internalisation as shown by phenotypic association, type 1 fimbrial blockade with soluble ligand (mannose) and by assessment of a type 1 fimbrial mutant. we propose that efficient internalisation of uropathogenic E. coli by the human urinary tract depends on co-operation between type 1 fimbriae-mediated adhesion and C3 receptor -ligand interaction.

  9. Design Research

    DEFF Research Database (Denmark)

    Design Research is a new interdisciplinary research area with a social science orientation at its heart, and this book explores how scientific knowledge can be put into practice in ways that are at once ethical, creative, helpful, and extraordinary in their results. In order to clarify the common...... aspects – in terms of features and approaches – that characterize all strands of research disciplines addressing design, Design Research undertakes an in depth exploration of the social processes involved in doing design, as well as analyses of the contexts for design use. The book further elicits...... ‘synergies from interdisciplinary perspectives’ by discussing and elaborating on differing academic perspectives, theoretical backgrounds, and design concept definitions, and evaluating their unique contribution to a general core of design research. This book is an exciting contribution to this little...

  10. Design spaces

    DEFF Research Database (Denmark)

    2005-01-01

    Digital technologies and media are becoming increasingly embodied and entangled in the spaces and places at work and at home. However, our material environment is more than a geometric abstractions of space: it contains familiar places, social arenas for human action. For designers, the integration...... of digital technology with space poses new challenges that call for new approaches. Creative alternatives to traditional systems methodologies are called for when designers use digital media to create new possibilities for action in space. Design Spaces explores how design and media art can provide creative...... alternatives for integrating digital technology with space. Connecting practical design work with conceptual development and theorizing, art with technology, and usesr-centered methods with social sciences, Design Spaces provides a useful research paradigm for designing ubiquitous computing. This book...

  11. Design Research as Conceptual Designing

    DEFF Research Database (Denmark)

    Ylirisku, Salu; Jacucci, Giulio; Sellen, Abigail

    2015-01-01

    define conceptual designing as a constructive framing and re-framing activity, which is mediated by and targeted at the creation of new design concepts. Conceptual designing as an approach is valuable for addressing the fuzziness and ambiguity typical of research that explores novel areas with new...... partners, methods and resources. It is by no means a new phenomenon, and the main contribution of the article is the clarification of conceptual designing as a particular approach to designing and researching. The approach embraces openness, resource-construction and collaboration. We conclude...... that conceptual designing can be especially useful in research and design projects that bring different kinds of people, organizations, technologies and domains together into the forming of new well-founded proposals for development. The presentation of conceptual designing in this paper is written...

  12. The F4 fimbrial antigen of Escherichia coli and its receptors.

    NARCIS (Netherlands)

    Van den Broeck, W; Cox, E; Oudega, B.; Goddeeris, B

    2000-01-01

    F4 or K88 fimbriae are long filamentous polymeric surface proteins of enterotoxigenic Escherichia coli (ETEC), consisting of so-called major (FaeG) and minor (FaeF, FaeH, FaeC, and probably FaeI) subunits. Several serotypes of F4 have been described, namely F4ab, F4ac, and F4ad. The F4 fimbriae

  13. Tetracycline promotes the expression of ten fimbrial operons in specific Salmonella enterica serovar Typhimurium isolates

    Science.gov (United States)

    Multidrug-resistant (MDR) Salmonella is associated with increased morbidity in humans and presents an important food safety concern. Antibiotic resistance among isolates of Salmonella enterica serovar Typhimurium has become especially prevalent as over 27 per cent of isolates from humans in the Unit...

  14. Type 1 fimbrial expression enhances Escherichia coli virulence for the urinary tract

    DEFF Research Database (Denmark)

    Connell, Hugh; Agace, William; Klemm, Per

    1996-01-01

    of Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory responce to infection. In a clinical study, we observed that disease severity was greater in children infected with E. coli O1:K1:H7 isolates expressing type 1 fimbriae than in those infected with type 1...... negative isolates of the same serotype. The E. coli O1:K1:H7 isolates had the same electrophoretic type, were hemolysin-negative, expressed P fimbriae, and carried the fim DNA sequences. When tested in a mouse urinary tract infection model, the type 1-positive E. coli O1:K1:H7 isolates survived inhigher...... urinary tract infection model. E. coli CN1016 reconstituted with type 1 fimbriae had restored virulence similar to that of the wild-type parent strain. These results show that type 1 fimbriae in the genetic background of a uropathogenic strain contribute to the pathogenesis of E. coli in the urinary tract....

  15. Type 1 fimbrial expression enhances Escherichia coli virulence for the urinary tract.

    OpenAIRE

    Connell, I; Agace, W; Klemm, P; Schembri, M; Mărild, S; Svanborg, C

    1996-01-01

    Type 1 fimbriae are adhesion organelles expressed by many Gram-negative bacteria. They facilitate adherence to mucosal surfaces and inflammatory cells in vitro, but their contribution to virulence has not been defined. This study presents evidence that type 1 fimbriae increase the virulence of Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory response to infection. In a clinical study, we observed that disease severity was greater in chil...

  16. ECO DESIGN IN DESIGN PROCESS

    Directory of Open Access Journals (Sweden)

    PRALEA Jeni

    2014-05-01

    Full Text Available Eco-design is a new domain, required by the new trends and existing concerns worldwide, generated by the necessity of adopting new design principles. New design principles require the designer to provide a friendly relationship between concept created, environment and consume. This "friendly" relationship should be valid both at present and in the future, generating new opportunities for product, product components or materials from which it was made. Awareness, by the designer, the importance of this new trend, permits the establishment of concepts that have as their objective the protection of present values and ensuring the legacy of future generations. Ecodesig, by its principles, is involved in the design process, from early stage, the stage of product design. Priority objective of the designers will consist in reducing the negative effects on the environment through the entire life cycle and after it is taken out of use. The main aspects of the eco-design will consider extending product exploitation, make better use of materials, reduction of emission of waste. The design process in the "eco"domein must be started by selecting the function of the concept, materials and technological processes, causing the shape of macro and micro geometric of the product through an analysis that involves optimizing and streamlining the product. This paper presents the design process of a cross-sports footwear concept, built on the basis of the principles of ecodesign

  17. Design Education

    DEFF Research Database (Denmark)

    Brandt, Eva

    2007-01-01

    In resent years the two main design schools in Denmark (Danmarks Designskole and Designskolen Kolding ) undergo many changes. The overall goal for both is to obtain status as a university, and they will be evaluated in this regard in 2010. Transforming a vocational school with long handicraft...... traditions into a research based institution for higher education is demanding. Danmarks Designskole is in the middle of this process, many activities are initiated, both employees and students are involved, and from outside representatives from various design professions. The design process has many...... stakeholders with various interests and opinions. The aim it is not to design a computer system, a service or product but re-designing curriculum, work procedures, self images etc. which support educating designers of the future. This paper reports on two investigations that have been carried through as part...

  18. Cooperative design

    DEFF Research Database (Denmark)

    Schmidt, Kjeld

    1998-01-01

    In the contemporary world, engineers and designers face huge challenges as they shift towards novel organizational concepts such as ‘concurrent engineering’ in order to manage increasing product diversity so as to satisfy customer demands while trying to accelerate the design process to deal...... they are facing. On one hand, designers need highly flexible ‘coordination mecha-nisms’ that can support horizontal coordination of large-scale distributed design projects, and on the other hand design organizations require versatile and ubiquitous infrastructures to be able to manage their ‘common informa...... with the competitive realities of a global market and decreasing product life cycles. In this environment, the coordination and integration of the myriads of interdependent and yet distributed and concurrent design activities becomes enormously complex. It thus seems as if CSCW technologies may be indispensable...

  19. Workspace Design

    DEFF Research Database (Denmark)

    Seim, Rikke

    Arbejdsmiljø adresseres sjældent i den klassike tekniske tilgang til arbejdspladsdesign. Workspace Design konceptet er et alternativ tilgang til design eller re-design af arbejdspladser, baseret på en socio-teknisk systemforståelse, hvor hovedprincipperne er 1) transformation af...... arbejdsmiljørådgiveren til facilitator af arbejdspladsdesignprocessen og 2) transformation af medarbejderne til co-designere af deres egen arbejdsplads. Dette ph.d.-projekt er en del af Workspace Design forskningsprogrammet som har udviklet og testet Workspace Design konceptet og de tilhørende metoder ved intervention i...... arbejdspladsdesignprocesser i tre virksomheder tilhørende henholdsvis industri-, service- og sundhedssektoren. Ph.d.-projektet har belyst hvordan en medarbejderinvolverende designproces kan iscenesættes og faciliteres af arbejdsmiljøprofessionelle ved hjælp af kreative, visuelle metoder inspireret af Participatory Design...

  20. Design culture and design education

    DEFF Research Database (Denmark)

    Riisberg, Vibeke; Bang, Anne Louise

    2014-01-01

    to change the education of future designers. This is an emerging field at a number of design schools across the world, among these Design School Kolding in Denmark. In this paper we understand and discuss design education as part of a cultural phenomenon. The aim of our research is to develop new dialogue...... tools for teaching fashion and textile students in order to stimulate new ways of thinking and engaging with users. By employing participatory design methods in the field of fashion and textiles, we seek to develop an alternative transformational strategy that may further the design of products....... In this paper we discuss ways in which design education might contribute in changing the current professional culture in order to meet the need for more sustainable futures....

  1. Integrated Design

    DEFF Research Database (Denmark)

    Jørgensen, Michael; Nielsen, M. W.; Strømann-Andersen, Jakob Bjørn

    2011-01-01

    and describe the decision process. Specific attention is given to how the engineering input was presented and how it was able to facilitate the design development. Site and context, building shape, organization of functions and HVAC-systems were all included to obtain a complete picture of the building......, low-energy consumption, and high-quality indoor environment. We use this case study to investigate how technical knowledge about building performance can be integrated into the conceptual design stage. We have selected certain points during the design process that represented design challenges...

  2. Design Diversity

    DEFF Research Database (Denmark)

    Dankl, Kathrina

    2014-01-01

    . The exhibition is oriented along disciplines such as inclusive design, which calls for products to be designed in such a way that they are equally attractive to people of all ages. Despite the existence of innovative design concepts, the number of well-designed products available on the market is low. While many...... courageous projects for "best agers" and "golden agers" never get beyond the prototype stage, products that paint a more "beige" picture of everyday life can be found in large numbers. This fact raises some key questions: Does the existing product culture reflect today's views on old age? Do contemporary...

  3. Team designing

    DEFF Research Database (Denmark)

    Denise J. Stokholm, Marianne

    2012-01-01

    Future wellbeing is depending on human competences in order to strengthen a sustainable development. This requires system thinking and ability to deal with complexity, dynamic and a vast of information. `We need to move away from present principles of breaking down problems into components and gi...... thinking and communication in design. Trying to answer the question: How can visual system models facilitate learning in design thinking and team designing?......Future wellbeing is depending on human competences in order to strengthen a sustainable development. This requires system thinking and ability to deal with complexity, dynamic and a vast of information. `We need to move away from present principles of breaking down problems into components and give...... in relation to a design-engineering education at Aalborg University. It will exemplify how the model has been used in workshops on team designing, challenged design learning and affected design competence. In specific it will investigate the influence of visual models of the perception of design, design...

  4. Design Compass

    DEFF Research Database (Denmark)

    Stokholm, Marianne Denise J.

    2006-01-01

    Design is moreover recognised as an important strategic tool in achieving competitive business´, products and services in a global market. As design becomes a more complex matter, due to a general increase in knowledge, requirements and internationalisation, more professions are involved....... As such it acts a managing tool for both leaders and participants in the design process. This paper builds on long term practical experiment with development and use of a simple tool to support management of complex design matters in diverse groups. Concerning education it has supported the development of new...

  5. Designated Places

    Data.gov (United States)

    California Natural Resource Agency — Census 2000 Place Names provides a seamless statewide GIS layer of places, including census designated places (CDP), consolidated cities, and incorporated places,...

  6. Design theory

    CERN Document Server

    2009-01-01

    This book deals with the basic subjects of design theory. It begins with balanced incomplete block designs, various constructions of which are described in ample detail. In particular, finite projective and affine planes, difference sets and Hadamard matrices, as tools to construct balanced incomplete block designs, are included. Orthogonal latin squares are also treated in detail. Zhu's simpler proof of the falsity of Euler's conjecture is included. The construction of some classes of balanced incomplete block designs, such as Steiner triple systems and Kirkman triple systems, are also given.

  7. Cryostat Design

    Energy Technology Data Exchange (ETDEWEB)

    Parma, V [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    This paper aims to give non-expert engineers and scientists working in the domain of accelerators a general introduction to the main disciplines and technologies involved in the design and construction of accelerator cryostats. Far from being an exhaustive coverage of these topics, an attempt is made to provide simple design and calculation rules for a preliminary design of cryostats. Recurrent reference is made to the Large Hadron Collider magnet cryostats, as most of the material presented is taken from their design and construction at CERN.

  8. Interior Design.

    Science.gov (United States)

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This document contains teacher's materials for an eight-unit secondary education vocational home economics course on interior design. The units cover period styles of interiors, furniture and accessories, surface treatments and lighting, appliances and equipment, design and space planning in home and business settings, occupant needs, acquisition…

  9. Opportunity Design

    DEFF Research Database (Denmark)

    Løwe Nielsen, Suna; Lassen, Astrid Heidemann; Nielsen, Louise Møller

    2013-01-01

    design”. The framework explains how opportunities intentionally and pro-actively can be designed from methods and processes of moving-in and moving-out. An illustrative case of opportunity design within the area of sustainable energy and electric cars is presented to link the theoretical discussion...

  10. Publication Design.

    Science.gov (United States)

    Nelson, Roy Paul

    This book is designed to solve the problem of coordinating art and typography with content in publications. Through text and illustrations, this book suggests ways to make pages and spreads in magazines, newspapers, and books attractive and readable. As a book of techniques, it is directed at potential and practicing art directors, designers, and…

  11. Designing friends

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; Nijholt, Antinus; Stronks, B.; van der Vet, P.E.; Rosenberg, D.

    2003-01-01

    Embodied Conversational Agents are virtual humans that can interact with humans using verbal and non-verbal forms of communication. In most cases, they have been designed for short interactions. This paper asks the question how one would start to design synthetic characters that can become your

  12. Design tools

    Science.gov (United States)

    Anton TenWolde; Mark T. Bomberg

    2009-01-01

    Overall, despite the lack of exact input data, the use of design tools, including models, is much superior to the simple following of rules of thumbs, and a moisture analysis should be standard procedure for any building envelope design. Exceptions can only be made for buildings in the same climate, similar occupancy, and similar envelope construction. This chapter...

  13. Integrated Design

    DEFF Research Database (Denmark)

    Lenau, Torben Anker

    1999-01-01

    A homepage on the internet with course material, lecture plan, student exercises, etc. Continuesly updated during the course Integrated Design (80402, 80403)......A homepage on the internet with course material, lecture plan, student exercises, etc. Continuesly updated during the course Integrated Design (80402, 80403)...

  14. Persuasive Design

    DEFF Research Database (Denmark)

    Gram-Hansen, Sandra Burri

    2013-01-01

    of the specific context. This paper argues that the claim of persuasive design may not be the ability to change the user’s attitude or behaviour towards a given subject, but rather on the ability to create designs, which adapt the context in a way, which facilitates the ability to act within the opportune moment....

  15. Japansk design

    DEFF Research Database (Denmark)

    Kural, René

    2005-01-01

    Artiklen udspringer af interviews med ti af Japans bedste møbeldesignere, grafikere, arkitekter og designfirmaer. Efter samtalerne var der tre træk ved japansk design, som trådte frem: god økonomi, fantasi og vovemod. Det bedste japanske design fusionerer vovemod med den unikke japanske kultur med...

  16. Intelligent Design

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2005-01-01

    Forestillingen om at naturen er designet af en guddommelig 'intelligens' er et smukt filosofisk princip. Teorier om Intelligent Design som en naturvidenskabeligt baseret teori er derimod helt forfærdelig.......Forestillingen om at naturen er designet af en guddommelig 'intelligens' er et smukt filosofisk princip. Teorier om Intelligent Design som en naturvidenskabeligt baseret teori er derimod helt forfærdelig....

  17. Performance Design

    DEFF Research Database (Denmark)

    Svabo, Connie

    Contribution to conference: Art and Presence The emerging field of Performance Design is unfolded as a bastard form of research/art/design/practice, with shapeshifting, monstruous, hybrid and transformational qualities. The potential for presencing, which emerges out of momentarily transgressing...

  18. Design law

    DEFF Research Database (Denmark)

    Schovsbo, Jens Hemmingsen; Riis, Thomas

    2017-01-01

    This book chapter describes, analyses and discusses the development of and the challenges to the legal protection og designs in Scandinavia and the EU......This book chapter describes, analyses and discusses the development of and the challenges to the legal protection og designs in Scandinavia and the EU...

  19. Furniture design

    CERN Document Server

    Smardzewski, Jerzy

    2015-01-01

    Maximizing reader insights into the principles of designing furniture as wooden structures, this book discusses issues related to the history of furniture structures, their classification and characteristics, ergonomic approaches to anthropometric requirements and safety of use. It presents key methods and highlights common errors in designing the characteristics of the materials, components, joints and structures, as well as looking at the challenges regarding developing associated design documentation. Including analysis of how designers may go about calculating the stiffness and endurance of parts, joints and whole structures, the book analyzes questions regarding the loss of furniture stability and the resulting threats to health of the user, putting forward a concept of furniture design as an engineering processes. Creating an attractive, functional, ergonomic and safe piece of furniture is not only the fruit of the work of individual architects and artists, but requires an effort of many people working ...

  20. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix; Wind, Simon

    2016-01-01

    In this paper, we identify the nexus between design (architecture, urban design, service design, etc.) and mobilities as a new and emerging research field. In this paper, we apply a “situational mobilities” perspective and take point of departure in the pragmatist question: “What design decisions...... and interventions affords this particular mobile situation?” The paper presents the contours of an emerging research agenda within mobilities research. The advent of “mobilities design” as an emerging research field points towards a critical interest in the material as well as practical consequences of contemporary......-making. The paper proposes that increased understanding of the material affordances facilitated through design provides important insight to planning and policymaking that at times might be in risk of becoming too detached from the everyday life of the mobile subject within contemporary mobilities landscapes....

  1. Factors affecting the initial adhesion and retention of the plant pathogen Xylella fastidiosa in the foregut of an insect vector.

    Science.gov (United States)

    Killiny, Nabil; Almeida, Rodrigo P P

    2014-01-01

    Vector transmission of bacterial plant pathogens involves three steps: pathogen acquisition from an infected host, retention within the vector, and inoculation of cells into susceptible tissue of an uninfected plant. In this study, a combination of plant and artificial diet systems were used to determine the importance of several genes on the initial adhesion and retention of the bacterium Xylella fastidiosa to an efficient insect vector. Mutant strains included fimbrial (fimA and pilB) and afimbrial (hxfA and hxfB) adhesins and three loci involved in regulatory systems (rpfF, rpfC, and cgsA). Transmission assays with variable retention time indicated that HxfA and HxfB were primarily important for early adhesion to vectors, while FimA was necessary for both adhesion and retention. The long pilus protein PilB was not deficient in initial adhesion but may be important for retention. Genes upregulated under the control of rpfF are important for both initial adhesion and retention, as transmission rates of this mutant strain were initially low and decreased over time, while disruption of rpfC and cgsA yielded trends similar to that shown by the wild-type control. Because induction of an X. fastidiosa transmissible state requires pectin, a series of experiments were used to test the roles of a polygalacturonase (pglA) and the pectin and galacturonic acid carbohydrates on the transmission of X. fastidiosa. Results show that galacturonic acid, or PglA activity breaking pectin into its major subunit (galacturonic acid), is required for X. fastidiosa vector transmission using an artificial diet system. This study shows that early adhesion and retention of X. fastidiosa are mediated by different factors. It also illustrates that the interpretation of results of vector transmission experiments, in the context of vector-pathogen interaction studies, is highly dependent on experimental design.

  2. ARE INCLUSIVE DESIGNERS DESIGNING INCLUSIVELY?

    DEFF Research Database (Denmark)

    Herriott, Richard

    2013-01-01

    of activity conforming to an authoritative design method. Analysis of the result showed that of the 66 cases, 4.5% reported carrying out all six categories of activity. 39.3% carried out or reported just one step. The study also found that the predominant focus of reported design activity is in the initial...

  3. Designing Users/Designing Innovation

    DEFF Research Database (Denmark)

    The paper addresses issues of user conceptualisation and representation in the processes of designing and innovating artifacts and use-practices. It is informed by early as well as more recent insights from technology studies within the new sociology of technology (e.g. Akrich 1995, Bijker & Law...... and competencies. Characteristic of these projects are the interplay between the social and the technical dimensions in the process of product development, and the students are expected to apply socio-technical methodologies in their strategies. The students’ need to inform the design through iteratively...... themes ranging from user-oriented design to product redesign and workspace design, etc. It is expected that some of the insights gained from these projects may be related outside of the immediate context of the classroom, to inform the notion of competencies in engineering design and sociotechnical...

  4. Design Anthropology

    DEFF Research Database (Denmark)

    This edited volume provides an introduction to the emerging field of design anthropology from the point of view of anthropologists engaging in its development. Contributors include young anthropologists with experience in the field and leading theoreticians, who combine to articulate the specific...... style of knowing involved in doing design anthropology. So far design anthropology has been developed mostly in the practice of industry and the public sector, in particular in Scandinavia and the US, and the sustained academic reflection to support this practice is still in its early stages. This book...... will contribute to this theoretical reflection and provide a reference for practitioners, teachers and students of anthropology, as well as design and innovation....

  5. Designing Organizations

    DEFF Research Database (Denmark)

    Book Description The design of organizations has been an ongoing concern of management theory and practice over the past several decades. Over this time, there has been little change in the fundamental theory, principles and concepts of Organization Design (OD). Recently organizational life has...... changed dramatically with the advent of: new communication systems, adaptive mechanisms, information technology, knowledge management systems, innovation processes and more. This book systemically examines these developments and their impact on OD with contributions from leading scholars in the area...... is a benchmark publication in the field of organization design. By focusing on recent developments in organization design, this book will help to create more thoughtful research and stronger empirical analyses in this important area of management and organization....

  6. Designing Organizations

    DEFF Research Database (Denmark)

    changed dramatically with the advent of: new communication systems, adaptive mechanisms, information technology, knowledge management systems, innovation processes and more. This book systemically examines these developments and their impact on OD with contributions from leading scholars in the area....... The individual chapters are organized into five sections: (1) Putting Contingency Theory in its Place, (2) Focus on Individuals who make up the Organization, (3) Innovation Processes and Organization Design, (4) Adaptation and Technology, and (5) Design for Performance. Each chapter examines aspects of the books...... is a benchmark publication in the field of organization design. By focusing on recent developments in organization design, this book will help to create more thoughtful research and stronger empirical analyses in this important area of management and organization....

  7. Design '82

    International Nuclear Information System (INIS)

    1982-01-01

    The papers in the symposium cover many aspects of the economy and effectiveness of chemical engineering design in industrial plants. Among the topics dealt with are the special problems associated with nuclear reprocessing plants. (U.K.)

  8. Persuasiv design

    DEFF Research Database (Denmark)

    Hasle, Per

    2011-01-01

    Purpose – The purpose of this paper is to introduce the theme issue on “Persuasive design”. Design/methodology/approach – This editorial describes the essential ideas and purposes of persuasive design (PD). PD's relation to other IT‐disciplines and rhetoric in general is discussed. A special...... to rhetoric and the concomitant implications for library and information systems is largely original (when compared with other discussions of PD)....

  9. Mechanical design

    Science.gov (United States)

    1976-01-01

    Design concepts for a 1000 mw thermal stationary power plant employing the UF6 fueled gas core breeder reactor are examined. Three design combinations-gaseous UF6 core with a solid matrix blanket, gaseous UF6 core with a liquid blanket, and gaseous UF6 core with a circulating blanket were considered. Results show the gaseous UF6 core with a circulating blanket was best suited to the power plant concept.

  10. Mechanisms Design

    DEFF Research Database (Denmark)

    Restrepo-Giraldo, John Dairo

    2006-01-01

    Most products and machines involve some kind of controlled movement. From window casements to DVD players, from harbor cranes to the shears to prune your garden, all these machines require mechanisms to move. This course intends to provide the analytical and conceptual tools to design such mechan......Most products and machines involve some kind of controlled movement. From window casements to DVD players, from harbor cranes to the shears to prune your garden, all these machines require mechanisms to move. This course intends to provide the analytical and conceptual tools to design...... using criteria such as size, performance parameters, operation environment, etc. Content: Understanding Mechanisms Design (2 weeks) Definitions, mechanisms representations, kinematic diagrams, the four bar linkage, mobility, applications of mechanisms, types of mechanisms, special mechanisms, the design......: equations for various mechanisms. At the end of this module you will be able to analyze existing mechanisms and to describe their movement. Designing mechanisms (7 weeks) Type synthesis and dimensional synthesis, function generation, path generation, three precision points in multi-loop mechanisms...

  11. Tank design

    International Nuclear Information System (INIS)

    Earle, F.A.

    1992-01-01

    This paper reports that aboveground tanks can be designed with innovative changes to complement the environment. Tanks can be constructed to eliminate the vapor and odor emanating from their contents. Aboveground tanks are sometimes considered eyesores, and in some areas the landscaping has to be improved before they are tolerated. A more universal concern, however, is the vapor or odor that emanates from the tanks as a result of the materials being sorted. The assertive posture some segments of the public now take may eventually force legislatures to classify certain vapors as hazardous pollutants or simply health risks. In any case, responsibility will be leveled at the corporation and subsequent remedy could increase cost beyond preventive measures. The new approach to design and construction of aboveground tanks will forestall any panic which might be induced or perceived by environmentalists. Recently, actions by local authorities and complaining residents were sufficient to cause a corporation to curtail odorous emissions through a change in tank design. The tank design change eliminated the odor from fuel oil vapor thus removing the threat to the environment that the residents perceived. The design includes reinforcement to the tank structure and the addition of an adsorption section. This section allows the tanks to function without any limitation and their contents do not foul the environment. The vapor and odor control was completed successfully on 6,000,000 gallon capacity tanks

  12. INFRASTRUCTURING DESIGN

    DEFF Research Database (Denmark)

    Ertner, Sara Marie

    The fact that the average citizen in Western societies is aging has significant implications for national welfare models. What some call ’the grey tsunami’ has resulted in suggestions for, and experiments in, re-designing healthcare systems and elderly care. In Denmark, one attempted solution...... that are imagined as the target group for welfare technology, and where are they located? Based on ethnographic explorations of ’welfare technology’ and related figures that include not only ’the elderly’, but also ’prototypes’ and ’partnership’ the dissertation analyses the processes and socio...... for collaborative design to happen. The implication of this is that technological design should not be imagined as the foundation for shaping more effective health care practices and better welfare. Instead, possibilities for improving practices through welfare technology emerge out of heterogeneous assemblages...

  13. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    are often still not engaged with in a sufficiently manner. Often social sciences keep distance to the physical and material as if the social was still to be understood as a realm separate of technology, architecture, and design (for a critique of this see; Latour 2005 and Urry 2000). This paper takes point......Within the so-called ‘mobilities turn’ (Adey 2010; Cresswell 2006; Urry 2007) much research has taken place during the last decade bringing mobilities into the centre of sociological analysis. However, the materiality and spatiality of artefacts, infrastructures, and sites hosting mobilities...... of departure in the sociological perspective termed ‘Staging Mobilities’ (Jensen 2013a) and utilizes this as an analytical frame for exploring cases of mobility design. The paper put focus on how the material shape, design and architectures of technologies, spaces and sites influence mobilities practices...

  14. Design thinking.

    Science.gov (United States)

    Brown, Tim

    2008-06-01

    In the past, design has most often occurred fairly far downstream in the development process and has focused on making new products aesthetically attractive or enhancing brand perception through smart, evocative advertising. Today, as innovation's terrain expands to encompass human-centered processes and services as well as products, companies are asking designers to create ideas rather than to simply dress them up. Brown, the CEO and president of the innovation and design firm IDEO, is a leading proponent of design thinking--a method of meeting people's needs and desires in a technologically feasible and strategically viable way. In this article he offers several intriguing examples of the discipline at work. One involves a collaboration between frontline employees from health care provider Kaiser Permanente and Brown's firm to reengineer nursing-staff shift changes at four Kaiser hospitals. Close observation of actual shift changes, combined with brainstorming and rapid prototyping, produced new procedures and software that radically streamlined information exchange between shifts. The result was more time for nursing, better-informed patient care, and a happier nursing staff. Another involves the Japanese bicycle components manufacturer Shimano, which worked with IDEO to learn why 90% of American adults don't ride bikes. The interdisciplinary project team discovered that intimidating retail experiences, the complexity and cost of sophisticated bikes, and the danger of cycling on heavily trafficked roads had overshadowed people's happy memories of childhood biking. So the team created a brand concept--"Coasting"--to describe a whole new category of biking and developed new in-store retailing strategies, a public relations campaign to identify safe places to cycle, and a reference design to inspire designers at the companies that went on to manufacture Coasting bikes.

  15. Dark Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    Any design idea or intervention in the world is based on an underpinning logic or a set of normative principles and values. At times such will be very explicit, at other times they will be unspoken and tacit. In this paper the underpinning values leading to power exercise, social exclusion, and d...... of technologies (e.g. Graham 2010). The paper re-works how inequalities are ‘staged’ through overt and covert design ideas and interventions shaping and re-shaping the social geography of a world increasingly marked by the rights, abilities, and opportunities to move freely – or not!...

  16. Design & Innovation

    DEFF Research Database (Denmark)

    Boelskifte, Per; Jørgensen, Ulrik

    2005-01-01

    The new design and innovation programme at DTU is challenging some of the standard concepts dominating most engineering educations. The programme, its background, context and basic educational ideas are presented and discussed in this paper. To build competences that match the need for innovative...... and design oriented engineers in industry and society has turned out to challenge a number of the standard – and often taken for granted – concepts in engineering education still dominated world wide by rather strict norms and concepts of learning that do not challenge the students creativity and innovative...

  17. Lighting Design

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Mullins, Michael

    2014-01-01

    of design developed from three experiments show how distinct qualitative and quantitative criteria in different disciplinary traditions can be integrated successfully, despite disparate technical/scientific, social scientific and art/humanities backgrounds. The model is applied to a pedagogical curriculum......Light as a multi-dimensional design element has fundamental importance for a sustainable environment. The paper discusses the need for an integration of scientific, technical and creative approaches to light and presents theory, methods and applications toward fulfilling this need. A theory...

  18. VLSI design

    CERN Document Server

    Einspruch, Norman G

    1986-01-01

    VLSI Electronics Microstructure Science, Volume 14: VLSI Design presents a comprehensive exposition and assessment of the developments and trends in VLSI (Very Large Scale Integration) electronics. This volume covers topics that range from microscopic aspects of materials behavior and device performance to the comprehension of VLSI in systems applications. Each article is prepared by a recognized authority. The subjects discussed in this book include VLSI processor design methodology; the RISC (Reduced Instruction Set Computer); the VLSI testing program; silicon compilers for VLSI; and special

  19. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    How is the width of the pavement shaping the urban experience? How is the material design of transport infrastructure and mobile technology affording social interaction in everyday life spaces? How do people inhabit these spaces with their bodies and in accordance to social and cultural norms...

  20. Designed communities?

    DEFF Research Database (Denmark)

    Stender, Marie

    2013-01-01

    In current residential spaces there seem to be an increasing emphasis on small-scale communities. A number of new, high profiled residential complexes thus seek to promote new ways of social living by rethinking architectural design, typologies and concepts. In this paper I explore the emergence ...

  1. Design junctions

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik

    2012-01-01

    . This case study illustrates how dominant regimes of practice, established through the conception of pathogen bacteria and antibacterial treatments and disinfection, are now creating signals that call into question fundamental design of hygiene practices. By examining the epistemic assumptions of scientific...

  2. Participatory Design

    DEFF Research Database (Denmark)

    Robertson, Toni; Simonsen, Jesper

    2012-01-01

    focus of later chapters. The target audience is identified, and the structure of the book explained. A short description of each chapter highlights its particular contributions as well as the associated challenges facing designers and researchers engaged in participatory approaches. The chapter...

  3. Designer's Identity

    DEFF Research Database (Denmark)

    Kunrath, Kamila; Cash, Philip; Li-Ying, Jason

    2016-01-01

    A designer’s professional identity (DPI) develops through both education and professional experience, building on core personality traits and innate skills. In this paper a systematic literature review and a secondary narrative review were developed in order to map personal attributes and design...

  4. Appraising design

    Science.gov (United States)

    2016-05-26

    Acronyms ADM Army Design Methodology AFRICOM Africa Command CAS Complex Adaptive System COCOM...the case studies. It does not analyze the moral forces of training, quality of troops, and readiness. It also does not analyze national strength in...Second Lebanese War.110 Issues included a lack of vests, medical equipment, radios, ammunition, night vision devices (NVD), and food and water for the

  5. Dwelling Designers

    Science.gov (United States)

    Szekely, George

    2012-01-01

    Children's inventions go far beyond track housing or Ethan Allen furniture; they foreshadow the most innovative ideas in building forms and interior designs. Children improvise with containers and find places in a home that suggest enticing dwellings. A drawer left open becomes a balcony, soap trays become cots, and the space between twin beds…

  6. Probabilistic Design

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, H. F.

    This chapter describes how partial safety factors can be used in design of vertical wall breakwaters and an example of a code format is presented. The partial safety factors are calibrated on a probabilistic basis. The code calibration process used to calibrate some of the partial safety factors...

  7. Intimate Design

    DEFF Research Database (Denmark)

    Søndergaard, Marie Louise Juul

    2017-01-01

    I examine how design can reflect on and critically discuss political and cultural issues of intimate technologies, such as gender and identity, embodied experiences, privacy, intimate data and sharing. In presenting my PhD project's background, research objectives, hypothesis and methodological...

  8. Collaborative Design

    Science.gov (United States)

    Broderick, Debora

    2014-01-01

    This practitioner research study investigates the power of multimodal texts within a real-world context and argues that a participatory culture focused on literary arts offers marginalized high school students opportunities for collaborative design and authoring. Additionally, this article invites educators to rethink the at-risk label. This…

  9. Integreret Design

    DEFF Research Database (Denmark)

    Helweg-Larsen, Klavs; Lenau, Torben Anker; Kristensen, Tore

    Integreret Design (ItD) var et tværdisciplinært kursus, der gennemførtes i samarbejde mellem Danmarks Designskole, Danmarks Tekniske Universitet og Handelshøjskolen i København i årene 1998 - 2001. Som støtte for undervisningen blev der udviklet et kompendium i bogform, som udgives af Danmarks...

  10. Didaktisk Design

    DEFF Research Database (Denmark)

    Sørensen, Birgitte Holm; Levinsen, Karin

    projekter - Individuelle fordybelsesprojekter. Forfatterne introducerer begrebet elever som didaktiske designere og viser med konkrete eksempler fra dansk, matematik og tværfaglige forløb, hvordan læreren med et overordnet rammedesign kan understøtte elevernes design af deres egne læreprocesser og dermed...

  11. Safety design

    International Nuclear Information System (INIS)

    Kunitomi, Kazuhiko; Shiozawa, Shusaku

    2004-01-01

    JAERI established the safety design philosophy of the HTTR based on that of current reactors such as LWR in Japan, considering inherent safety features of the HTTR. The strategy of defense in depth was implemented so that the safety engineering functions such as control of reactivity, removal of residual heat and confinement of fission products shall be well performed to ensure safety. However, unlike the LWR, the inherent design features of the high-temperature gas-cooled reactor (HTGR) enables the HTTR meet stringent regulatory criteria without much dependence on active safety systems. On the other hand, the safety in an accident typical to the HTGR such as the depressurization accident initiated by a primary pipe rupture shall be ensured. The safety design philosophy of the HTTR considers these unique features appropriately and is expected to be the basis for future Japanese HTGRs. This paper describes the safety design philosophy and safety evaluation procedure of the HTTR especially focusing on unique considerations to the HTTR. Also, experiences obtained from an HTTR safety review and R and D needs for establishing the safety philosophy for the future HTGRs are reported

  12. Design i Danmark = Danish Design?

    DEFF Research Database (Denmark)

    Lentz, Uffe

    2003-01-01

    Titlen på denne forelæsning har 3 led skønt det ser ud som om der er 4. Design i Danmark er en geografisk afgrænsning af et ikke særligt veldefineret begreb, der både kan dække over ting og aktiviteter, mens Danish Design er en fælles hat man har markedsført en række produkter under, for at få...... værdiopfattelse før fra det ene produkt til det andet. Et Brand ville det hedde i dag....

  13. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the background of the ‘mobilities turn’ (e.g. Cresswell 2006, Urry 2007) this book articulates a new and emerging research field, namely that of ‘m......Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the background of the ‘mobilities turn’ (e.g. Cresswell 2006, Urry 2007) this book articulates a new and emerging research field, namely...... that of ‘mobilities design’. The book revolves around the following research question: How are design decisions and interventions staging mobilities? It builds upon the Staging Mobilities model (Jensen 2013) in an explorative inquiry into the problems and potentials of the design of mobilities. The exchange value...

  14. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    2016-01-01

    of life’ for billions of people in the everyday life. This paper is structured in three parts. After the general introduction we present the mobilities theory perspective of ‘staging mobilities’ and connects this to the empirical phenomenon of parking lots and their design. The paper ends in section three......Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the backgound of the ‘mobilities turn’ (for short review paper on this see; Sheller 2011, Vannini 2010) this paper proposes a further development...... of the perspective in the direction of a material and design oriented turn. In order to fulfill this purpose we articulate a new and emerging research field, namely that of ‘mobilities design’. In our understanding time has come to articulate ‘Mobilities Design’ as a dedicated research field in and of its own...

  15. Design Transformations

    DEFF Research Database (Denmark)

    Morrison, Ann; Knoche, Hendrik

    2014-01-01

    Purpose – Taking a case study approach, we synchronised two courses to focus on the students working with learning and applying tools in the one course and acting on understandings gained to produce artefacts in the other. Design/methodology/approach – Working with real users throughout all stages...... focused evaluation methods using tangible representations; identified the relationship from these findings for subsequent re-design rationales; and discussed and critiqued each other’s work using multiple feedback, teach-back and discursive strategies. Findings – We found that in-depth coverage...... of material, working with real data and users at all stages of assessment and producing visualisations from evaluations, naturally forced student motivation to act and redesign better solutions. We noted improved attendance and students reported high engagement and content appreciation. Research limitations...

  16. Organization Design

    OpenAIRE

    Milton Harris; Artur Raviv

    2002-01-01

    This paper attempts to explain organization structure based on optimal coordination of interactions among activities. The main idea is that each manager is capable of detecting and coordinating interactions only within his limited area of expertise. Only the CEO can coordinate company wide interactions. The optimal design of the organization trades off the costs and benefits of various configurations of managers. Our results consist of classifying the characteristics of activities and manager...

  17. Designing Privacy-by-Design

    NARCIS (Netherlands)

    Rest, J.H.C. van; Boonstra, D.; Everts, M.H.; Rijn, M. van; Paassen, R.J.G. van

    2014-01-01

    The proposal for a new privacy regulation d.d. January 25th 2012 introduces sanctions of up to 2% of the annual turnover of enterprises. This elevates the importance of mitigation of privacy risks. This paper makes Privacy by Design more concrete, and positions it as the mechanism to mitigate these

  18. Design livre: cannibalistic interaction design

    NARCIS (Netherlands)

    van Amstel, Frederick; Vassao, C.A.; Ferraz, G.B.; Formia, E.M.

    2012-01-01

    This paper provides a historical account of cannibalism as used to explain how Brazilians integrate foreign cultural influences into their own culture and introduces a design praxis based on it. From Modernism to Digital Culture, cannibalism is a recurring tactic used to overcome cultural traditions

  19. Mechanical Design

    Energy Technology Data Exchange (ETDEWEB)

    Shook, Richard; /Marquette U. /SLAC

    2010-08-25

    The particle beam of the SXR (soft x-ray) beam line in the LCLS (Linac Coherent Light Source) has a high intensity in order to penetrate through samples at the atomic level. However, the intensity is so high that many experiments fail because of severe damage. To correct this issue, attenuators are put into the beam line to reduce this intensity to a level suitable for experimentation. Attenuation is defined as 'the gradual loss in intensity of any flux through a medium' by [1]. It is found that Beryllium and Boron Carbide can survive the intensity of the beam. At very thin films, both of these materials work very well as filters for reducing the beam intensity. Using a total of 12 filters, the first 9 being made of Beryllium and the rest made of Boron Carbide, the beam's energy range of photons can be attenuated between 800 eV and 9000 eV. The design of the filters allows attenuation for different beam intensities so that experiments can obtain different intensities from the beam if desired. The step of attenuation varies, but is relative to the thickness of the filter as a power function of 2. A relationship for this is f(n) = x{sub 0}2{sup n} where n is the step of attenuation desired and x{sub 0} is the initial thickness of the material. To allow for this desired variation, a mechanism must be designed within the test chamber. This is visualized using a 3D computer aided design modeling tool known as Solid Edge.

  20. Mechanical Design

    International Nuclear Information System (INIS)

    2010-01-01

    The particle beam of the SXR (soft x-ray) beam line in the LCLS (Linac Coherent Light Source) has a high intensity in order to penetrate through samples at the atomic level. However, the intensity is so high that many experiments fail because of severe damage. To correct this issue, attenuators are put into the beam line to reduce this intensity to a level suitable for experimentation. Attenuation is defined as 'the gradual loss in intensity of any flux through a medium' by (1). It is found that Beryllium and Boron Carbide can survive the intensity of the beam. At very thin films, both of these materials work very well as filters for reducing the beam intensity. Using a total of 12 filters, the first 9 being made of Beryllium and the rest made of Boron Carbide, the beam's energy range of photons can be attenuated between 800 eV and 9000 eV. The design of the filters allows attenuation for different beam intensities so that experiments can obtain different intensities from the beam if desired. The step of attenuation varies, but is relative to the thickness of the filter as a power function of 2. A relationship for this is f(n) = x 0 2 n where n is the step of attenuation desired and x 0 is the initial thickness of the material. To allow for this desired variation, a mechanism must be designed within the test chamber. This is visualized using a 3D computer aided design modeling tool known as Solid Edge.

  1. Designed Places

    DEFF Research Database (Denmark)

    Stender, Marie

    The 2008 financial crisis has left traces in the built environment of Copenhagen like many other places: Building projects are left unfinished or their function or finish is changed due to new economic circumstances. An ethnographic exploration of these traces exposes central aspects of what is a......, and when the ceilings leak water, the residents suspect it to be a consequence of the crisis. The paper discusses how market forces interact with the material surroundings we inhabit and explores the relationship between controlled and uncontrollable in the design of places....

  2. Group Design Problems in Engineering Design Graphics.

    Science.gov (United States)

    Kelley, David

    2001-01-01

    Describes group design techniques used within the engineering design graphics sequence at Western Washington University. Engineering and design philosophies such as concurrent engineering place an emphasis on group collaboration for the solving of design problems. (Author/DDR)

  3. Democratic design experiments

    DEFF Research Database (Denmark)

    Ehn, Pelle; Brandt, Eva; Halse, Joachim

    2016-01-01

    Designers and design researchers are increasingly exploring societal challenges through engagements with issues that call forward new publics and new modes of democratic citizenship. Whatever this is called design activism, social design, adversarial design, participatory design or something else...

  4. Contract design

    International Nuclear Information System (INIS)

    Bradley, P.

    2006-01-01

    The current state of the electric power industry in Ontario was discussed with particular reference to the procurement of contracts and why the Ontario Power Authority (OPA) must be contracting to resolve many of Ontario's electricity issues. As Ontario increasingly relies on imports and natural gas-fired generation, the price of electricity continues to rise given that supply is at a low level. In addition to the generation gap, there are also several transmission constrained areas in Ontario, particularly in the Greater Toronto Area (GTA). The OPA announced 2 projects totalling 1900 MW to relieve congestion. According to the Independent Electricity System Operator (IESO), the total potential opportunity for new generation by 2015 is about 5,000 to 7,000 megawatts. OPA is expected to launch procurement processes for up to 1000 MW of cogeneration, 250 MW of province-wide conservation initiatives, 1900 MW of generation in the western part of the GTA, and 600 MW of generation in downtown Toronto. New nuclear capacity is also anticipated in addition to renewables and conservation/demand management (CDM) initiatives. The OPA's competitive procurement processes will include requests for expressions of interest, requests for qualifications and requests for proposals. The challenge of balancing the technical complexities and realities of procuring generation assets with the need for a fair procurement process was discussed. Contracts will be designed to react to market signals and will include 3 styles: tariff style, tolling style and standard offer contract. OPA will make every effort to balance generator and ratepayer interests. 6 figs

  5. Design Argumentation in Academic Design Education

    DEFF Research Database (Denmark)

    Dalsgaard, Peter; Dindler, Christian; Fritsch, Jonas

    2013-01-01

    We explore design argumentation as a resource when teaching interaction design in a university setting. We propose that design argumentation can help bridge between practice-based design education and theoretical issues from university curricula. In this paper, we outline the idea of design...

  6. Dansk design - English edition

    DEFF Research Database (Denmark)

    Dickson, Thomas

    Indhold: Hvad er design?; Hvor kommer dansk design fra?; Produktdesign; Tekstil- og tøjdesign; Design af møbler og boligindretning; Bygningen og design; Arbejdets design; Transportdesign; Offentligt design; Grafisk design; Nye tider og en ny slags design...

  7. System design projects for undergraduate design education

    Science.gov (United States)

    Batill, S. M.; Pinkelman, J.

    1993-01-01

    Design education has received considerable in the recent past. This paper is intended to address one aspect of undergraduate design education and that is the selection and development of the design project for a capstone design course. Specific goals for a capstone design course are presented and their influence on the project selection are discussed. The evolution of a series of projects based upon the design of remotely piloted aircraft is presented along with students' perspective on the capstone experience.

  8. Sharing the design intent between industrial designers and engineering designers

    DEFF Research Database (Denmark)

    Laursen, Esben Skov; Møller, Louise

    2016-01-01

    The aim of the paper is to understand the challenges sharing the product frame between industrial designers with the engineering designers. The study is based on six case studies. The analysis showed correspondence between industrial designers and engineering designers in their understanding...... of the key elements of the context and concept. However the analysis also showed a lack of correspondence between the industrial designers and engineering designers in regards to the product framing and thereby how the different elements of the product frame is connected and interrelated....

  9. Service design : Tuning the industrial design profession

    NARCIS (Netherlands)

    Sleeswijk Visser, F.

    2013-01-01

    Design is not only about the design and production of goods, but is increasingly addressing complex social issues nowadays. Roles of designers are becoming more and more varied, and at the same time other professionals are increasingly using design tools in their business, organizational or other

  10. Designing for critique, designing for reflection

    DEFF Research Database (Denmark)

    Løfgreen, Lars Bo

    2010-01-01

    litteraturliste og et stikordsregister. Bogen rummer kapitlerne: “Visual topography: analysing the visual context of an interactive interface” af Lise Agerbæk, “Designing (with) Creativity” af Heidi Philipsen, “Designing for critique, designing for reflection – the (re)emergence of aesthetics in current design...

  11. Designing interfaces patterns for effective interaction design

    CERN Document Server

    Tidwell, Jenifer

    2005-01-01

    This convenient resource offers advice on creating user-friendly interface designs--whether they're delivered on the Web, a CD, or a smart" devices like a cell phone. Solutions to common UI design problems are expressed as a collection of patterns--each one containing concrete examples, recommendations, and warnings. Intended for designers with basic UI design knowledge

  12. Enhancing biomedical design with design thinking.

    Science.gov (United States)

    Kemnitzer, Ronald; Dorsa, Ed

    2009-01-01

    The development of biomedical equipment is justifiably focused on making products that "work." However, this approach leaves many of the people affected by these designs (operators, patients, etc.) with little or no representation when it comes to the design of these products. Industrial design is a "user focused" profession which takes into account the needs of diverse groups when making design decisions. The authors propose that biomedical equipment design can be enhanced, made more user and patient "friendly" by adopting the industrial design approach to researching, analyzing, and ultimately designing biomedical products.

  13. Design methods and design theory for architectural design management

    NARCIS (Netherlands)

    Achten, H.H.; Otter, den A.F.H.J.; Achten, H.H.; Pels, H.J.

    2008-01-01

    Most parties that an architectural design manager meets in daily practice are engaged to some degree with design. What these parties are actually doing in a project is contingent with the concrete design project. Additionally, each party has some stake, and may employ different strategies to solve

  14. Managing collaborative design

    NARCIS (Netherlands)

    Sebastian, R.

    2007-01-01

    Collaborative design has been emerging in building projects everywhere. The more complex a building project becomes, the closer and more intensive collaboration between the design actors is required. This research focuses on collaborative design in the conceptual architecture design phase,

  15. Design for Accessibility

    DEFF Research Database (Denmark)

    Herriott, Richard

    2012-01-01

    A report on how nine rail builder, operators and transport designers deal with design for accessibility......A report on how nine rail builder, operators and transport designers deal with design for accessibility...

  16. Design is an Attitude

    DEFF Research Database (Denmark)

    Eriksen, Kaare Riise

    2005-01-01

    Arttiklen beskriver den mexicanske designer Rafael Davidsons arbejder gennem en menneskealder, samt hans visioner for mexicansk design i fremtiden.......Arttiklen beskriver den mexicanske designer Rafael Davidsons arbejder gennem en menneskealder, samt hans visioner for mexicansk design i fremtiden....

  17. Design Research between Design and Research

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Markussen, Thomas

    2011-01-01

    The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through...... design strand have argued, that architecture and design research must follow an architecture and design methodology – designing – and be communicated by means of architecture and design media – images and artefacts. Essentially, this view sees no difference between architecture and design research...... and practice, as expressed in the notion of research as ‘artistic innovation work’. On the other hand, the pressure to expand research in architecture and design has seen a movement towards adopting traditional research paradigms from the technical and social sciences and humanities. For many architects...

  18. Design Games for In-Situ Design

    DEFF Research Database (Denmark)

    Kristiansen, Erik

    2013-01-01

    The mobile culture has spawned a host of context-based products, like location-based and tag-based applications. This presents a new challenge for the designer. There is a need of design methods that acknowledge the context and allows it to influence the design ideas. This article focuses...... on a design problem where an in-situ design practice may further the early design process: the case of designing a pervasive game. Pervasive games are computer games, played using the city as a game board and often using mobile phones with GPS. Some contextual design methods exist, but we propose an approach...... sitestorming, is based on a game using Situationistic individual exploration of the site and different types of game cards, followed by a joint evaluation of the generated ideas. A series of evaluations showed that the designers found the method enjoyable to use, that the method motivated idea generation...

  19. Design of modern experiments

    International Nuclear Information System (INIS)

    Park, Sung Hweon

    1984-03-01

    This book is for researchers and engineers, which is written to focus on practical design of experiments. It gives descriptions of conception of design of experiments, basic statistics theory, one way design of experiment, two-way layout without repetition, two-way layout with repetition, partition, a correlation analysis and regression analysis, latin squares, factorial design, design of experiment by table of orthogonal arrays, design of experiment of response surface, design of experiment on compound, Evop, and design of experiment of taguchi.

  20. Computational Design Tools for Integrated Design

    DEFF Research Database (Denmark)

    Holst, Malene Kirstine; Kirkegaard, Poul Henning

    2010-01-01

    In an architectural conceptual sketching process, where an architect is working with the initial ideas for a design, the process is characterized by three phases: sketching, evaluation and modification. Basically the architect needs to address three areas in the conceptual sketching phase......: aesthetical, functional and technical requirements. The aim of the present paper is to address the problem of a vague or not existing link between digital conceptual design tools used by architects and designers and engineering analysis and simulation tools. Based on an analysis of the architectural design...... process different digital design methods are related to tasks in an integrated design process....

  1. papA gene of avian pathogenic Escherichia coli.

    Science.gov (United States)

    Kariyawasam, Subhashinie; Nolan, Lisa K

    2011-12-01

    P fimbrial adhesins may be associated with the virulence of avian pathogenic Escherichia coli (APEC). However, most APECs are unable to express P fimbriae even when they are grown under conditions that favor P fimbrial expression. This failure can be explained by the complete absence of the pap operon or the presence of an incomplete pap operon in Pap-negative APEC strains. In the present study, we analyzed the pap operon, specifically the papA gene that encodes the major fimbrial shaft, to better understand the pap gene cluster at the genetic level. First, by PCR, we examined a collection of 500 APEC strains for the presence of 11 genes comprising the pap operon. Except for papA, all the other genes of the operon were present in 38% to 41.2% of APEC, whereas the papA was present only in 10.4% of the APEC tested. Using multiplex PCR to probe for allelic variants of papA, we sought to determine if the low prevalence of papA among APEC was related to genetic heterogeneity of the gene itself. It was determined that the papA of APEC always belongs to the F11 allelic variant. Finally, we sequenced the 'papA region' from two papA-negative strains, both of which contain all the other genes of the pap operon. Interestingly, both strains had an 11,104-bp contig interruptingpapA at the 281-bp position. This contig harbored a streptomycin resistance gene and a classic Tn10 transposon containing the genes that confer tetracycline resistance. However, we noted that the papA gene of every papA-negative APEC strain was not interrupted by an 11,104-bp contig. It is likely that transposons bearing antibiotic resistance genes have inserted within pap gene cluster of some APEC strains, and such genetic events may have been selected for by antibiotic use.

  2. Crystallization and preliminary X-ray diffraction analysis of CfaE, the adhesive subunit of the CFA/I fimbriae from human enterotoxigenic Escherichia coli

    International Nuclear Information System (INIS)

    Li, Yong-Fu; Poole, Steven; Rasulova, Fatima; Esser, Lothar; Savarino, Stephen J.; Xia, Di

    2006-01-01

    The adhesin CfaE of the CFA/I fimbriae from human enterotoxigenic E. coli has been crystallized. CfaE crystals diffracted X-rays to better than 2.4 Å and phasing was solved by the SIRAS method. Enterotoxigenic Escherichia coli (ETEC) represents a formidable food and waterborne diarrheal disease threat of global importance. The first step in ETEC pathogenesis is bacterial attachment to small-intestine epithelial cells via adhesive fimbriae, many of which are genetically related to the prototype colonization factor antigen I (CFA/I). The minor fimbrial subunit CfaE is required for initiation of CFA/I fimbrial assembly and mediates bacterial attachment to host cell-surface receptors. A donor-strand complemented variant of CfaE (dscCfaE) was expressed with a hexahistidine tag, purified to homogeneity and crystallized using the hanging-drop vapor-diffusion method. X-ray diffraction data sets were collected to 2.4 Å resolution for both native and derivatized crystals and showed the symmetry of space group P6 2 22, with unit-cell parameters a = b = 142.9, c = 231.9 Å. Initial phases were derived from the SIRAS approach and electron density showed two molecules in the crystallographic asymmetric unit. Sequence assignments were aided by anomalous signals from the selenium of an SeMet-derivatized crystal and from S atoms of a native crystal

  3. Analog circuit design designing high performance amplifiers

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The third volume Designing High Performance Amplifiers applies the concepts from the first two volumes. It is an advanced treatment of amplifier design/analysis emphasizing both wideband and precision amplification.

  4. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  5. Design rules for dynamic organization design

    DEFF Research Database (Denmark)

    Burton, Richard; Obel, Børge

    2013-01-01

    Organizational design rules are contingent if-then statements about what a good design should be for a given situation. Today’s challenge is to look forward to devise organization design rules for a different future with greater uncertainty and greater interdependency – all with dynamic performance...... demands. These new demands call for new design rules for coordination, incentives and leadership, among others. Our existing rules are mostly based upon past experience and empirical studies of what is. What might be – going beyond what we have observed and explained of yesterday and today to help design...... for a future new situation – is a disciplined response to examine the new contingencies of organizational design and their design consequences. Computational laboratories permit us to go beyond what is to develop and examine new design possibilities and boundaries to explore a future world of what might be. We...

  6. Money and Design

    Directory of Open Access Journals (Sweden)

    Artur Borcuch

    2015-01-01

    Full Text Available The purpose of this article is to analyze the influence of the money design on willingness to make purchases. In this paper, we focus on three aspects that structure the relation between money and design: the link between design and finance (in general, determinants of design and perspective of currency design. The main research problem explored in this paper is: Does the money design have influence on the willingness to make purchases by employees/employers at design studios, design students and students of economics/management? The main hypothesis is as follows – the more experience in design practice, the more important is money design.

  7. Differential decay of RNA of the CFA/I fimbrial operon and control of relative gene expression.

    OpenAIRE

    Jordi, B J; op den Camp, I E; de Haan, L A; van der Zeijst, B A; Gaastra, W

    1993-01-01

    CFA/I fimbriae on human enterotoxigenic Escherichia coli are composed of the CfaB protein, the product of the second gene of the CFA/I operon. We show here that CfaB is expressed at a higher level than other proteins of the CFA/I operon. mRNA encoding the CfaB protein is much more abundant than mRNA encoding CfaA, the first protein, together with CfaB or mRNA encoding CfaA only. Only one promoter, upstream of cfaA, is present. These data indicate that a primary transcript containing cfaA and ...

  8. Reduction of Salmonella Enteritidis in the spleens of hens by bacterins that vary in fimbrial protein SefD

    Science.gov (United States)

    Gene sefD is part of operon sefABCD, and it is required for production of the SEF14 fimbria by Salmonella Enteritidis. We compared strains that varied in SefD content for their ability to reduce recovery of Salmonella Enteritidis from the spleens of hens infected by parenteral challenge. The two bac...

  9. Cloning, Expression, and Immunogenicity of Fimbrial-F17A Subunit Vaccine against Escherichia coli Isolated from Bovine Mastitis

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-01-01

    Full Text Available There is a need to identify and select new promising immunodominant antigens that have the ability to provide protective immunity against E. coli causing bovine mastitis. Recently we showed that f17a was found to be the most prevalent and crucial virulent factor among the pathogenic E. coli isolated from bovine mastitis. Here, in this report, the recombinant F17A based subunit vaccine adjuvant with MF59 was tested for immunogenicity against E. coli in a murine model. The vaccinated mice did not show any abnormal behavioral changes and histopathological lesions after vaccination. The specific antibody level against F17A was significantly higher in MF59-adjuvant-group, and also lasted for longer duration with a significant (P<0.01 production level of IgG1 and IgG2a. Moreover, we noted higher survival rate in mice injected with F17A-MF59-adjuvant group after challenging with the clinical E. coli strain. Our findings of bacterial clearance test revealed that elimination rate from liver, spleen, and kidney in MF59-adjuvant-group was significantly higher than the control group. Finally, the proportion of CD4+T cells was increased, while CD8+ was decreased in MF59-adjuvant group. In conclusion, the current study reveals the capability of F17A-MF59 as a potential vaccine candidate against pathogenic E. coli causing mastitis in dairy animals.

  10. Design as Value Celebration: Rethinking Design Argumentation

    DEFF Research Database (Denmark)

    Halstrøm, Per Liljenberg

    2016-01-01

    This article introduces knowledge of the rhetorical genre of epideictic to design. The aim is to provide designers with concepts that stimulate their ability to deliberate about design choices and explore the arguments they may be making about the human-made world. The article begins with explora...

  11. Ergonomics in design or design in ergonomics

    DEFF Research Database (Denmark)

    Binder, Thomas

    2005-01-01

    Design in Scandinavia has a long tradition of participation in the development of society. Designers in the Nordic countries have taken pride in concerning themselves with problems of everyday living and the design communities at large have been committed proponents of a socially responsible appr...

  12. Eindhoven school for technological design : design education and design research

    NARCIS (Netherlands)

    Trum, H.M.G.J.; Oxman, R.M.; Bax, M.F.Th.

    1995-01-01

    Nine years after starting the two-year post-graduate programme on technological design [Ackermans and Trum, 1988], Eindhoven University of Technology (EUT) decided to enhance the development of synthesis-oriented engineering education by establishing a post-graduate school for technological design.

  13. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  14. The Distributed Criterion Design

    Science.gov (United States)

    McDougall, Dennis

    2006-01-01

    This article describes and illustrates a novel form of the changing criterion design called the distributed criterion design, which represents perhaps the first advance in the changing criterion design in four decades. The distributed criterion design incorporates elements of the multiple baseline and A-B-A-B designs and is well suited to applied…

  15. Medicines by Design

    Science.gov (United States)

    ... Home > Science Education > Medicines By Design Medicines By Design Spotlight Nature's Medicine Cabinet A Medicine's Life Inside ... hunt for drugs of the future. Medicines By Design in PDF | E-PUB Tell Us What You ...

  16. Design Sea State

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    National codes of practice which specifies the design wave climate on a given location do not yet exist. Nevertheless, decision on the design wave climate is one of the most important tasks of the designer....

  17. Responsive web design workflow

    OpenAIRE

    LAAK, TIMO

    2013-01-01

    Responsive Web Design Workflow is a literature review about Responsive Web Design, a web standards based modern web design paradigm. The goals of this research were to define what responsive web design is, determine its importance in building modern websites and describe a workflow for responsive web design projects. Responsive web design is a paradigm to create adaptive websites, which respond to the properties of the media that is used to render them. The three key elements of responsi...

  18. Design of chemical plant

    International Nuclear Information System (INIS)

    Lee, Dong Il; Kim, Seung Jae; Yang, Jae Ho; Ryu, Hwa Won

    1993-01-01

    This book describes design of chemical plant, which includes chemical engineer and plan for chemical plant, development of chemical process, cost engineering pattern, design and process development, general plant construction plan, project engineering, foundation for economy on assets and depreciation, estimation for cost on capital investment and manufacturing cost, design with computers optimal design and method like fluid mechanics design chemical device and estimation for cost, such as dispatch of material and device writing on design report and appendixes.

  19. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  20. The Communication Between Designer and Design Receiver

    DEFF Research Database (Denmark)

    Dai, Zheng; Dai, Yan

    2009-01-01

    When people think about a product,the first impression always mainly influences the result.Product is the medium of communication between designer and designer receiver.Because both of them have varied different experience and background,the information would be biased during the transferring...... process.The common symbols which can be recognized by both of designer and receiver are the key tools for communication.In some case,the same symbol in one product would be leads to different receiver impression.Generally,impression includes 3 aspects:aesthetics,function, and emotion.Designer needs...... to create an attractive and accurate impression in product from these 3 aspects.For facing the dilemma of communication,some experimental approaches can help designer deal with unique and diversity situations.Solving the detail problem in each step could keep the original meaning of designer....

  1. Integrated circuit design using design automation

    International Nuclear Information System (INIS)

    Gwyn, C.W.

    1976-09-01

    Although the use of computer aids to develop integrated circuits is relatively new at Sandia, the program has been very successful. The results have verified the utility of the in-house CAD design capability. Custom IC's have been developed in much shorter times than available through semiconductor device manufacturers. In addition, security problems were minimized and a saving was realized in circuit cost. The custom CMOS IC's were designed at less than half the cost of designing with conventional techniques. In addition to the computer aided design, the prototype fabrication and testing capability provided by the semiconductor development laboratory and microelectronics computer network allows the circuits to be fabricated and evaluated before the designs are transferred to the commercial semiconductor manufacturers for production. The Sandia design and prototype fabrication facilities provide the capability of complete custom integrated circuit development entirely within the ERDA laboratories

  2. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  3. Design for Play

    DEFF Research Database (Denmark)

    Feder, Karen

    2017-01-01

    Abstract The purpose of the new Design for Play initiative is to inspire and educate designers to design for the future of play. To create “play ambassadors” equipped with excellent tools, methods, approaches and mind-sets to design for the playful human being in an ever-changing world. To teach...... and inspire children to grow up to be creative designers of their own life and the world around them. The Design for Play research team will study the interplay between people, processes and products in design for play and support the development of playful designers, playful solutions and playful experiences...

  4. Analyses for designing objects in mechanical design

    International Nuclear Information System (INIS)

    Nakajima, Norihiro; Miyamura, Hiroko N.; Kawakami, Yoshiaki; Kawamura, Takuma

    2015-01-01

    Defining factors to induce the damage that can be assumed in the mechanical structures, it is a loaded work to analyze a damage possibility point derived by the assumption phenomenon that can occur is, but it is the important designing process. Taking factors caused by the earthquake as an example, and simulating the phenomenon that can be assumed, the computational result was analyzed with information visualization. A damage possibility point by analyzing the result mathematically. The illustration of analytical results may give points to designers as means for a designer to recognize a damage possibility point from the sensitivity of the designer. (author)

  5. Performative Urban Design

    DEFF Research Database (Denmark)

    Samson, Kristine

    2011-01-01

    visitors and participants to engage and interact with the city. Inspired by Lefebvre statement that "the most beautiful cities were those where festivals were not planned in advance” (Lefebvre 1987:36), I will discuss how urban designers can design engaging spaces, where the potentials of the city can...... unfold. Is it, for instance, the formal aesthetics of the design or rather the socio-cultural codes of the existing urban space that engage people? The paper engages in three urban performance designs: 1) The 10th Avenue Plaza at the Highline in New York 2) The temporary installations at Boble Plads......Urban design has come to mean many things. From the architectural masterplans to the informal urban design in temporary spaces and event designs. The paper will focus on urban designs engaging urban designs. Engaging urban design can broadly be understood as temporary design installations inviting...

  6. Solar Design Workbook

    Energy Technology Data Exchange (ETDEWEB)

    Franta, G.; Baylin, F.; Crowther, R.; Dubin, F.; Grace, A., Griffith, J.W.; Holtz, M.; Kutscher, C.; Nordham, D.; Selkowitz, S.; Villecco, M.

    1981-06-01

    This Solar Design Workbook presents solar building design applications for commercial buildir^s. The book is divided into four sections. The first section describes the variety of solar applications in buildings including conservation aspects, solar fundamentals, passive systems, active systems, daylighting, and other solar options. Solar system design evaluation techniques including considerations for building energy requirements, passive systems, active systems, and economics are presented in Section II. The third section attempts to assist the designer in the building design process for energy conservation and solar applications including options and considerations for pre-design, design, and post-design phases. The information required for the solar design proee^ has not been fully developed at this time. Therefore, Section III is incomplete, but an overview of the considerations with some of the design proces elements is presented. Section IV illustrates ease studies that utilize solar applications in the building design.

  7. OPTIMIZATION OF OPTIMIZATION OF DESIGN FORMULA DESIGN ...

    African Journals Online (AJOL)

    User

    Keywords: reinforced concrete slabs, flexure, m. 1. Introduction ntroduction ntroduction. An evaluation of the flexural resistance of reinforced concrete solid slabs with the optimu weight required for structural safety a economy and as stated in design codes. 5] is presented. It is a well-known fact by many design enginee.

  8. Reframing Design: Design Thinking and Mediation Theory

    NARCIS (Netherlands)

    Verbeek, Peter P.C.C.

    2015-01-01

    Design Thinking’ has proven to be a fruitful way to deal with societal problems and challenges. But what does it in fact mean to approach problems as design problems? What does it imply for our ways to understand societal challenges, and for the ways in which we address them? In order to answer

  9. Design Thinking Pedagogy: The Educational Design Ladder

    Science.gov (United States)

    Wrigley, Cara; Straker, Kara

    2017-01-01

    As global industries change and technology advances, traditional education systems might no longer be able to supply companies with graduates who possess an appropriate mix of skills and experience. The recent increased interest in Design Thinking as an approach to innovation has resulted in its adoption by non-design-trained professionals. This…

  10. Ethical Design Fiction

    DEFF Research Database (Denmark)

    Jensen, Thessa; Vistisen, Peter

    2017-01-01

    In this paper we examine how ethical challenges can be approached in and through design fiction. To do so, we develop a new framework for analysis as well as creation of design fictions. Our main focus will be on design fiction within a strategical setting, connecting the notion of design fiction...

  11. Empirical research through design

    NARCIS (Netherlands)

    Keyson, D.V.; Bruns, M.

    2009-01-01

    This paper describes the empirical research through design method (ERDM), which differs from current approaches to research through design by enforcing the need for the designer, after a series of pilot prototype based studies, to a-priori develop a number of testable interaction design hypothesis

  12. Delimiting Inclusive Design

    DEFF Research Database (Denmark)

    Herriott, Richard

    2014-01-01

    This paper was written as an answer to the question raised by my PhD dissertation on accessibility through user-centred and Inclusive Design (ID) methods: can Inclusive Design be delimited? The literature on Inclusive Design deals almost entrirely with consumer product design and assistive...

  13. Design, Desire, and Difference

    Science.gov (United States)

    Leander, Kevin M.; Boldt, Gail

    2018-01-01

    In response to the rise in popularity of concepts of "design" in education research, pedagogy, and curriculum design, in this article we consider how the New London Group conceived of the role of student design practices as an outcome of pedagogy, as well as the parallel role of design in teaching practices. In this descriptive analysis,…

  14. Designing Healthcare Solutions

    Directory of Open Access Journals (Sweden)

    Devorah E. Klein

    2009-11-01

    Full Text Available Innovation is generated when designers collaborate with scientists and clinicians. Who are designers? Professionals trained to uncover people’s spoken and unspoken needs (human factors researchers, to generate tangible products and services that address these needs in new and better ways (industrial and graphic designers, and to ensure that the design intent is preserved in the final manufactured form (engineers.

  15. Analysis of Design Documentation

    DEFF Research Database (Denmark)

    Hansen, Claus Thorp

    1998-01-01

    In design practice a process where a satisfactory solution is created within limited resources is required. However, since the design process is not well understood, research into how engineering designers actually solve design problems is needed. As a contribution to that end a research project...

  16. Design as Gesamtkunstwerk

    DEFF Research Database (Denmark)

    Munch, Anders V.

    Three texts on the historical development of ideas of total design: "The Art of Transgression" on contemporary projects between art, design and architecture; "Design as Gesamtkunstwerk" on the early modern total designs from Morris to Gropius (but mirrored in Panton) & "Throughout any Scale...

  17. Instant responsive web design

    CERN Document Server

    Simmons, Cory

    2013-01-01

    A step-by-step tutorial approach which will teach the readers what responsive web design is and how it is used in designing a responsive web page.If you are a web-designer looking to expand your skill set by learning the quickly growing industry standard of responsive web design, this book is ideal for you. Knowledge of CSS is assumed.

  18. DOE handbook: Design considerations

    International Nuclear Information System (INIS)

    1999-04-01

    The Design Considerations Handbook includes information and suggestions for the design of systems typical to nuclear facilities, information specific to various types of special facilities, and information useful to various design disciplines. The handbook is presented in two parts. Part 1, which addresses design considerations, includes two sections. The first addresses the design of systems typically used in nuclear facilities to control radiation or radioactive materials. Specifically, this part addresses the design of confinement systems and radiation protection and effluent monitoring systems. The second section of Part 1 addresses the design of special facilities (i.e., specific types of nonreactor nuclear facilities). The specific design considerations provided in this section were developed from review of DOE 6430.1A and are supplemented with specific suggestions and considerations from designers with experience designing and operating such facilities. Part 2 of the Design Considerations Handbook describes good practices and design principles that should be considered in specific design disciplines, such as mechanical systems and electrical systems. These good practices are based on specific experiences in the design of nuclear facilities by design engineers with related experience. This part of the Design Considerations Handbook contains five sections, each of which applies to a particular engineering discipline

  19. CBETA Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Hoffstaetter, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mayes, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-06-08

    This Design Report describes the baseline design of the Cornell-BNL ERL Test Accelerator, as it exists on the date of its publication in June 2017. The Design Report will not change frequently in the future. In contrast, the parameter sheets that summarize the CBETA design will respond as quickly and as thoroughly as necessary to maintain con guration control.

  20. CBETA Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Hoffstaetter, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mayes, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-06-08

    This Design Report describes the baseline design of the Cornell-BNL ERL Test Accelerator, as it exists on the date of its publication in June 2017. The Design Report will not change frequently in the future. In contrast, the parameter sheets that summarize the CBETA design will respond as quickly and as thoroughly as necessary to maintain configuration control.

  1. Early Building Design

    DEFF Research Database (Denmark)

    Østergård, Torben; Jensen, Rasmus Lund; Maagaard, Steffen

    2017-01-01

    Highlights •Development of a design methodology that can handle the vast design space in early building design. •A global design space is modelled from extensive Monte Carlo simulations. •Sensitivity analysis methods applied to guide decision-makers. •Interactive visualizations help the multi-act...

  2. DOE handbook: Design considerations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-01

    The Design Considerations Handbook includes information and suggestions for the design of systems typical to nuclear facilities, information specific to various types of special facilities, and information useful to various design disciplines. The handbook is presented in two parts. Part 1, which addresses design considerations, includes two sections. The first addresses the design of systems typically used in nuclear facilities to control radiation or radioactive materials. Specifically, this part addresses the design of confinement systems and radiation protection and effluent monitoring systems. The second section of Part 1 addresses the design of special facilities (i.e., specific types of nonreactor nuclear facilities). The specific design considerations provided in this section were developed from review of DOE 6430.1A and are supplemented with specific suggestions and considerations from designers with experience designing and operating such facilities. Part 2 of the Design Considerations Handbook describes good practices and design principles that should be considered in specific design disciplines, such as mechanical systems and electrical systems. These good practices are based on specific experiences in the design of nuclear facilities by design engineers with related experience. This part of the Design Considerations Handbook contains five sections, each of which applies to a particular engineering discipline.

  3. Design of canals

    CERN Document Server

    Swamee, P K

    2015-01-01

    The book presents firsthand material from the authors on design of hydraulic canals. The book discusses elements of design based on principles of hydraulic flow through canals. It covers optimization of design based on usage requirements and economic constraints. The book includes explicit design equations and design procedures along with design examples for varied cases. With its comprehensive coverage of the principles of hydraulic canal design, this book will prove useful to students, researchers, and practicing engineers. End-of-chapter pedagogical elements make it ideal for use in graduate courses on hydraulic structures offered by most civil engineering departments across the world.

  4. Design and Iconic Brands

    Directory of Open Access Journals (Sweden)

    2015-11-01

    Full Text Available The VW Beetle, Apple, Porsche … many iconic brands have reached their status with groundbreaking designs. But what makes these designs so special? And is it really the design factor that accounts for the overall success of a brand? Dr. Walter de Silva shares with us his thoughts on iconic designs, the design process and the role of design in branding. Open your heart and mind to his extensive experience in developing designs for Volkswagen, Audi and other brands of the Volkswagen Group

  5. Ergonomic Product Design 21

    International Nuclear Information System (INIS)

    Kwon, Yeong Guk

    1996-09-01

    This book explains basic of ergonomic product design with human engineering, image engineering and strategy of that design, ergonomic industrial design, which includes product design to access the human engineering in development of new product and customer satisfaction, application technology of image engineering, industrial design of human engineering item and strategy of human engineering, a good ergonomic design. It also tells of examples of convenient design for human such as hardware product and software product in automobile, telephones for ergonomic product in the future, new goods and new technology, ergonomic product in house and office, and computers and robots in the future.

  6. Organizing design work

    DEFF Research Database (Denmark)

    Scheuer, John Damm

    2016-01-01

    The aim of this paper is to demonstrate the importance of the kind of understanding of organizing that is implied by design theories for project managers' understanding and organizing of design work. Five theories and their organizing consequences for project managers organizing of design work...... are analyzed. The paper contributes to design research and organization studies by putting the organizing of design projects on the research agenda. It also contributes by demonstrating the importance of being aware of the ontological and epistemological assumptions and organizing consequences of different...... design theories. The selected theories of design thus represent different views on what design is, address different design areas and are based on different ontological and epistemological assumptions that influence their views on how design processes should be organized....

  7. Designing For Democracy

    DEFF Research Database (Denmark)

    Knutz, Eva; Markussen, Thomas; Mårbjerg Thomsen, Signe

    2014-01-01

    there are already a number of approaches available which in one way or the other address the relationship between design, democracy and power. We provide an account of participatory design, adversarial design and design activism thereby pointing towards design?s potential for re-distributing power and authority......n this paper we focus on ?patient-democracy? and ?shared decision-making? seen from the perspective of design practice and design research. In the research on democracy in healthcare it is rarely questioned what forms of democracy underlies these concepts. We have examined three different theories...... of democracy and the democratic practices that belong to each of these. For designers working to increase patient democracy it is of vital importance to be able to distinguish different structures underlying democratic practices and to work out methods for prototyping democracy. In design research...

  8. Conceptualizing Aesthetics in Design

    DEFF Research Database (Denmark)

    Folkmann, Mads Nygaard

    2018-01-01

    The aim of this chapter is to introduce and discuss aesthetics as an approach to understand how design frames experience. In doing so, the chapter combines two philosophical interests in design, design phenomenology and design aesthetics, in order to promote a framework for discussing the impact...... of aesthetic meaning construction on experience. First, the chapter raises the phenomenological question of the relationship between design and experience, specifically, how design conditions experience. Second, in looking at aesthetics in terms of a) the sensual appeal of design, b) design objects...... as aesthetic media that frame modes of understanding, and c) contextual factors, such as media, influencing what is regarded as aesthetic, it is the thesis of the chapter that a reflective concept of design aesthetics can be employed to differentiate between three different ways in which design frame our...

  9. Participatory workspace design

    DEFF Research Database (Denmark)

    Seim, Rikke; Broberg, Ole

    2010-01-01

    Ergonomics are rarely addressed directly in the design and re-design of workspaces in Denmark. Often architects, engineers and other actors design the workspaces on the basis of for example spatial, technological or finan-cial considerations, thereby making ergonomics a by-product of the design...... process. However, by introducing ergonomists in the role of ‘workspace de-signers’ early in the design process, ergonomic considerations as well as the involvement of employees, can be integrated in the design process. In this article we demonstrate the use of the workspace design approach in a case study...... where an industrial manufacturer is undergoing a major technological change: going from labour intensive manual work to a highly automated production. The workspace design team, which included the company’s OHS consultant, designed the intervention as a participatory design process by using visually...

  10. Reliable Design Versus Trust

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    This presentation focuses on reliability and trust for the users portion of the FPGA design flow. It is assumed that the manufacturer prior to hand-off to the user tests FPGA internal components. The objective is to present the challenges of creating reliable and trusted designs. The following will be addressed: What makes a design vulnerable to functional flaws (reliability) or attackers (trust)? What are the challenges for verifying a reliable design versus a trusted design?

  11. Managing collaborative design

    OpenAIRE

    Sebastian, R.

    2007-01-01

    Collaborative design has been emerging in building projects everywhere. The more complex a building project becomes, the closer and more intensive collaboration between the design actors is required. This research focuses on collaborative design in the conceptual architecture design phase, especially during the elaboration of the masterplan and the development of the preliminary building designs. This research is descriptive and has two aims. First, it aims at describing the characteristics a...

  12. Video Design Games

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Christensen, Kasper Skov; Iversen, Ole Sejer

    We introduce Video Design Games to train educators in teaching design. The Video Design Game is a workshop format consisting of three rounds in which participants observe, reflect and generalize based on video snippets from their own practice. The paper reports on a Video Design Game workshop...... in which 25 educators as part of a digital fabrication and design program were able to critically reflect on their teaching practice....

  13. Designing Futures in Indonesia

    OpenAIRE

    Alexandra Crosby

    2016-01-01

    Design is a wide reaching and unruly idea, often associated with seamless global mobility, ubiquitous consumerism, elite urban tastes, and fast paced economic growth. But design is also increasingly understood to be operating at edges, as a necessary response to the ethical and political challenges of advanced global capitalism. Design is both the problem and the solution, and effects everything. As Tony Fry writes ‘Design–the designer and designed objects, images, systems and things–shapes t...

  14. Mechanizing Exploratory Game Design

    OpenAIRE

    Smith, Adam Marshall

    2012-01-01

    Game design is an art form that deals with inherently interactive artifacts. Game designers craft games (assembled from rule systems and content), but they really seek to manipulate play: the interaction between games and players. When developing new games that are similar to past games, a designer may rely on previous experience with related designs and relatively easy access to players familiar with conventional design choices. When exploratorily venturing into uncharted territory, uncoveri...

  15. Control system design guide

    Energy Technology Data Exchange (ETDEWEB)

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  16. Design professional activity analysis in design management

    Directory of Open Access Journals (Sweden)

    Claudia de Souza Libanio

    2013-08-01

    Full Text Available Design use perception, as an essential element for achieving competitive advantage, also suggests the need to manage the design activities in companies. However, a few is discussed about the activity of these design professionals who participate in this process, their roles, functions and competencies, including  their connections to a company and other involved sectors. This article aims to analyze, during the design management processes, the work relations of design professionals connected to organizations both internal and externally, in order to comprehend the structure and intervenient factors on the activity of these professionals, as well as the interactions with their main coworkers. The methodology was exploratory and qualitative, using in-depth interviews with three design professionals. Subsequently, the responses were analyzed allowing the comparison of these obtained data to the theoretical bases researched. Through this case study, it was possible to realize the aspects and the structure of the design professional activity, connected intern and externally to organizations, as well as its relations with the main coworkers.

  17. Digital Interior Design by Stailia Design Oy

    OpenAIRE

    Lindroos, Jaana

    2017-01-01

    The objective of the thesis work is to research and create a web based service in a field of interior design. With my project, I am hoping to find out whether this kind of web service in the field of interior design can work in general and that the process together with the actual order form on internet is smooth from both customer and company point of view. The company has interior design related services but none entirely executed on the web. The target is to create a totally new service/pr...

  18. Database modeling and design logical design

    CERN Document Server

    Teorey, Toby J; Nadeau, Tom; Jagadish, HV

    2011-01-01

    Database systems and database design technology have undergone significant evolution in recent years. The relational data model and relational database systems dominate business applications; in turn, they are extended by other technologies like data warehousing, OLAP, and data mining. How do you model and design your database application in consideration of new technology or new business needs? In the extensively revised fifth edition, you'll get clear explanations, lots of terrific examples and an illustrative case, and the really practical advice you have come to count on--with design rules

  19. Database modeling and design logical design

    CERN Document Server

    Teorey, Toby J; Nadeau, Tom; Jagadish, HV

    2005-01-01

    Database systems and database design technology have undergone significant evolution in recent years. The relational data model and relational database systems dominate business applications; in turn, they are extended by other technologies like data warehousing, OLAP, and data mining. How do you model and design your database application in consideration of new technology or new business needs? In the extensively revised fourth edition, you'll get clear explanations, lots of terrific examples and an illustrative case, and the really practical advice you have come to count on--with design rul

  20. The design explorer project

    DEFF Research Database (Denmark)

    Pejtersen, Annelise Mark; Sonnenwald, Diane H.; Buur, Jacob

    1997-01-01

    the 'Design Explorer' research project whose goal is to specify requirements for an information system that will effectively help design team members from different domains and organizational cultures to locate and utilize diverse information sources and interact more effectively throughout the design process....... The project introduces a new approach to support of design; instead of design guidelines, support is given by creating a transparent information environment in which designers can navigate freely according to their individual preferences. The project is based on a framework that structures the dimensions......, or categories, of domain information which need to be available for a system or product designer/design team in order to determine the characteristics of the artefact, or object of design. These dimensions include information about the different work domains in which the product plays a role during its lifetime...

  1. The interactive design collaboratorium

    DEFF Research Database (Denmark)

    Bødker, Susanne; Petersen, Marianne Graves; Krogh, Peter Gall

    2001-01-01

    This paper reports on experimental process in which a prototype was developed of an interactive design collaboatorium, in cooperation with a group of usability designers. In a longterm research cooperation, this usability group has changed its work practice in order to work in the design...... collaboratorium. The design collaboratorium was developed to move usability design away from a lab towards an open physical and organizational space where designer, users and engineers meet and collaborate, or work alongside each other. The cooperation between researchers and the usability gruop has resulted...... in practical experimentation in projects and in design of an experimental design collaboratorium emploing electronic whiteboards, 3D design documentation, etc. This experimental prototype has been evaluated in cooperative workshops. We report on the results of this evaluation....

  2. Building theory through design

    DEFF Research Database (Denmark)

    Markussen, Thomas

    2017-01-01

    This chapter deals with a fundamental matter of concern in research through design: how can design work lead to the building of new theory? Controversy exists about the balance between theory and design work in research through design. While some researchers see theory production as the scientific...... hallmark of this type of research, others argue for design work being the primary achievement, with theory serving the auxiliary function of inspiring new designs. This paper demonstrates how design work and theory can be appreciated as two equally important outcomes of research through design. To set...... the scene, it starts out by briefly examining ideas on this issue presented in existing research literature. Hereafter, it introduces three basic forms in which design work can lead to theory that is referred to as extending theories, scaffolding theories and blending theories. Finally, it is discussed how...

  3. Understanding representations in design

    DEFF Research Database (Denmark)

    Bødker, Susanne

    1998-01-01

    Representing computer applications and their use is an important aspect of design. In various ways, designers need to externalize design proposals and present them to other designers, users, or managers. This article deals with understanding design representations and the work they do in design....... The article is based on a series of theoretical concepts coming out of studies of scientific and other work practices and on practical experiences from design of computer applications. The article presents alternatives to the ideas that design representations are mappings of present or future work situations...... and computer applications. It suggests that representations are primarily containers of ideas and that representation is situated at the same time as representations are crossing boundaries between various design and use activities. As such, representations should be carriers of their own contexts regarding...

  4. Radiological design guide

    International Nuclear Information System (INIS)

    Evans, R.A.

    1994-01-01

    The purpose of this design guide is to provide radiological safety requirements, standards, and information necessary for designing facilities that will operate without unacceptable risk to personnel, the public, or the environment as required by the US Department of Energy (DOE). This design guide, together with WHC-CM-4-29, Nuclear Criticality Safety, WHC-CM-4-46, Nonreactor Facility Safety Analysis, and WHC-CM-7-5, Environmental Compliance, covers the radiation safety design requirements at Westinghouse Hanford Company (WHC). This design guide applies to the design of all new facilities. The WHC organization with line responsibility for design shall determine to what extent this design guide shall apply to the modifications to existing facilities. In making this determination, consideration shall include a cost versus benefit study. Specifically, facilities that store, handle, or process radioactive materials will be covered. This design guide replaces WHC-CM-4-9 and is designated a living document. This design guide is intended for design purposes only. Design criteria are different from operational criteria and often more stringent. Criteria that might be acceptable for operations might not be adequate for design

  5. Can design science be used for design?

    DEFF Research Database (Denmark)

    Rose, Jeremy; Markfoged, Kim; Andersen, Jesper Lund

    2010-01-01

    software development projects. They studied the literature, chose appropriate starting theories, designed their own development processes, used them to build small mobile applications, documented their experiences and evaluated those experiences by writing research articles. A more experienced researcher...

  6. Parametric Design Strategies for Collaborative Urban Design

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Yıldırım, Miray Baş; Özkar, Mine

    2013-01-01

    to the collaboration between professionals, participation by different non-professional stakeholders, such as residents, local authorities, non-governmental organizations and investors, is another important component of collaborative urban design processes. The involvement of community in decision making process...... implications of planning and design decisions, unless they are presented with relatively detailed architectural models, whether physical or virtual. This however, typically presents steep demands in terms of time and resources. As a foundation for our work with parametric urban design lies the hypothesis...... to solve different scripting challenges. The paper is organized into an introduction, three main sections and closing section with conclusions and perspectives. The first section of the paper gives a theoretical discussion of the notion of collaborative design and the challenges of collaborative urban...

  7. Nanobody mediated inhibition of attachment of F18 Fimbriae expressing Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Kristof Moonens

    Full Text Available Post-weaning diarrhea and edema disease caused by F18 fimbriated E. coli are important diseases in newly weaned piglets and lead to severe production losses in farming industry. Protective treatments against these infections have thus far limited efficacy. In this study we generated nanobodies directed against the lectin domain of the F18 fimbrial adhesin FedF and showed in an in vitro adherence assay that four unique nanobodies inhibit the attachment of F18 fimbriated E. coli bacteria to piglet enterocytes. Crystallization of the FedF lectin domain with the most potent inhibitory nanobodies revealed their mechanism of action. These either competed with the binding of the blood group antigen receptor on the FedF surface or induced a conformational change in which the CDR3 region of the nanobody displaces the D″-E loop adjacent to the binding site. This D″-E loop was previously shown to be required for the interaction between F18 fimbriated bacteria and blood group antigen receptors in a membrane context. This work demonstrates the feasibility of inhibiting the attachment of fimbriated pathogens by employing nanobodies directed against the adhesin domain.

  8. F9 fimbriae of uropathogenic Escherichia coli are expressed at low temperature and recognise Galβ1-3GlcNAc-containing glycans.

    Directory of Open Access Journals (Sweden)

    Daniël J Wurpel

    Full Text Available Uropathogenic Escherichia coli (UPEC is the leading causative agent of urinary tract infections (UTI in the developed world. Among the major virulence factors of UPEC, surface expressed adhesins mediate attachment and tissue tropism. UPEC strains typically possess a range of adhesins, with type 1 fimbriae and P fimbriae of the chaperone-usher class the best characterised. We previously identified and characterised F9 as a new chaperone-usher fimbrial type that mediates biofilm formation. However, the regulation and specific role of F9 fimbriae remained to be determined in the context of wild-type clinical UPEC strains. In this study we have assessed the distribution and genetic context of the f9 operon among diverse E. coli lineages and pathotypes and demonstrated that f9 genes are significantly more conserved in a UPEC strain collection in comparison to the well-defined E. coli reference (ECOR collection. In the prototypic UPEC strain CFT073, the global regulator protein H-NS was identified as a transcriptional repressor of f9 gene expression at 37°C through its ability to bind directly to the f9 promoter region. F9 fimbriae expression was demonstrated at 20°C, representing the first evidence of functional F9 fimbriae expression by wild-type E. coli. Finally, glycan array analysis demonstrated that F9 fimbriae recognise and bind to terminal Galβ1-3GlcNAc structures.

  9. Salmonella enterica serotype Typhimurium Std fimbriae bind terminal α (1,2)fucose residues in the cecal mucosa

    Science.gov (United States)

    Chessa, Daniela; Winter, Maria G.; Jakomin, Marcello; Bäumler, Andreas J.

    2013-01-01

    SUMMARY The std operon encodes a fimbrial adhesin of Salmonella enterica serotype Typhimurium that is required for attachment to intestinal epithelial cells and for cecal colonization in the mouse. To study the mechanism by which this virulence factor contributes to colonization we characterized its binding specificity. Std-mediated binding to human colonic epithelial (Caco-2) cells could be abrogated by removing N-linked glycans. Adherence of Std fimbriated S. Typhimurium to Caco-2 cells could be blocked by co-incubation with H type 2 oligosaccharide (Fucα1-2Galβ1-4GlcNAc) or by pretreatment of cells with α1-2 fucosidase. In contrast, pretreatment of Caco-2 cells with neuraminidase or co-incubation with the type 2 disaccharide precursor (Galβ1-4GlcNAc) did not reduce adherence of Std fimbriated S. Typhimurium. Binding of purified Std fimbriae to Fucα1-2Galβ1-4GlcNAc in a solid phase binding assay was competitively inhibited by Ulex europaeus agglutinin-I (UEA-I), a lectin specific for Fucα1-2 moieties. Purified Std fimbriae and UEA both bound to a receptor localized in the mucus layer of the murine cecum. These data suggest that the std operon encodes an adhesin that binds an α1-2 fucosylated receptor(s) present in the cecal mucosa. PMID:19183274

  10. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    1991-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  11. Handbook of optical design

    CERN Document Server

    Malacara-Hernández, Daniel

    2013-01-01

    Handbook of Optical Design, Third Edition covers the fundamental principles of geometric optics and their application to lens design in one volume. It incorporates classic aspects of lens design along with important modern methods, tools, and instruments, including contemporary astronomical telescopes, Gaussian beams, and computer lens design. Written by respected researchers, the book has been extensively classroom-tested and developed in their lens design courses. This well-illustrated handbook clearly and concisely explains the intricacies of optical system design and evaluation. It also di

  12. Professional ASPNET Design Patterns

    CERN Document Server

    Millett, Scott

    2010-01-01

    Professional ASP.NET Design Patterns will show you how to implement design patterns in real ASP.NET applications by introducing you to the basic OOP skills needed to understand and interpret design patterns. A sample application used throughout the book is an enterprise level ASP.NET website with multi-tiered, SOA design techniques that can be applied to your future ASP.NET projects. Read about each design pattern in detail, including how to interpret the UML design, how to implement it in ASP.NET, its importance for ASP.NET development, and how it's integrated into the final project.

  13. Introduction to combinatorial designs

    CERN Document Server

    Wallis, WD

    2007-01-01

    Combinatorial theory is one of the fastest growing areas of modern mathematics. Focusing on a major part of this subject, Introduction to Combinatorial Designs, Second Edition provides a solid foundation in the classical areas of design theory as well as in more contemporary designs based on applications in a variety of fields. After an overview of basic concepts, the text introduces balanced designs and finite geometries. The author then delves into balanced incomplete block designs, covering difference methods, residual and derived designs, and resolvability. Following a chapter on the e

  14. Optimal Hospital Layout Design

    DEFF Research Database (Denmark)

    Holst, Malene Kirstine

    foundation. The basis of the present study lies in solving the architectural design problem in order to respond to functionalities and performances. The emphasis is the practical applicability for architects, engineers and hospital planners for assuring usability and a holistic approach of functionalities...... a correlation matrix. The correlation factor defines the framework for conceptual design, whereby the design considers functionalities and their requirements and preferences. It facilitates implementation of evidence-based design as it is prepared for ongoing update and it is based on actual data. Hence......, this contribution is a model for hospital design, where design derives as a response to the defined variables, requirements and preferences....

  15. REDOing Design Education

    DEFF Research Database (Denmark)

    Morelli, Nicola; Götzen, Amalia De

    2017-01-01

    that are being developed in design education and research. The value in use, the infrastructuring and the governance levels are explained with the specific tools and approaches required according to the specific aim of the design activity: that is, whether it is about understanding, transforming or communicating......Service design education is still young and it is still interpreted in many different ways, according to the design programs where it usually plays a minor role. Very few education schemes provide a complete curriculum on service design, facing the challenge of equipping a designer who will want...

  16. Microwave circulator design

    CERN Document Server

    Linkhart, Douglas K

    2014-01-01

    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  17. KALIMER design concept report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Kyu; Kim, Young Cheol; Kim, Young In; Kim, Young Gyun; Kim, Eui Kwang; Song, Hoon; Chung, Hyun Tai; Hwang, Woan; Nam, Cheol; Sub, Sim Yoon; Kim, Yeon Sik; Whan, Wim Myung; Min, Byung Tae; Yoo, Bong; Lee, Jae Han; Lee, Hyeong Yeon; Kim, Jong Bum; Koo, Gyeong Hoi; Ham, Chang Shik; Kwon, Kee Choon; Kim, Jung Taek; Park, Jae Chang; Lee, Jung Woon; Lee, Yong Hee; Kim, Chang Hwoi; Sim, Bong Shick; Hahn, Do Hee; Choi, Jong Hyeun; Kwon, Sang Woon

    1997-07-01

    KAERI is working for the development of KALIMER and work is being done for methodology development, experimental facility set up and design concept development. The development target of KALIMER has been set as to make KALIMER safer, more economic, more resistant to nuclear proliferation, and yield less impact on the environment. To achieve the target, study has been made for setting up the design concept of KALIMER including the assessment of various possible design alternatives. This report is the results of the study for the KALIMER concept study and describes the design concept of KALIMER. The developed design concept study and describes the design concept of KALIMER. The developed design concept is to be used as the starting point of the next development phase of conceptual design and the concept will be refined and modified in the conceptual design phase. The scope of the work has been set as the NSSS and essential BOP systems. For systems, NSSS and functionally related major BOP are covered. Sizing and specifying conceptual structure are covered for major equipment. Equipment and piping are arranged for the parts where the arrangement is critical in fulfilling the foresaid intention of setting up the KALIMER design concept. This report consists of 10 chapters. Chapter 2 is for the top level design requirements of KALIMER and it serves as the basis of KALIMER design concept development. Chapter 3 summarizes the KALIMER concept and describes the general design features. The remaining chapters are for specific systems. (author). 29 tabs., 37 figs.

  18. KALIMER design concept report

    International Nuclear Information System (INIS)

    Park, Chang Kyu; Kim, Young Cheol; Kim, Young In; Kim, Young Gyun; Kim, Eui Kwang; Song, Hoon; Chung, Hyun Tai; Hwang, Woan; Nam, Cheol; Sim Yoon Sub; Kim, Yeon Sik; Wim Myung Whan; Min, Byung Tae; Yoo, Bong; Lee, Jae Han; Lee, Hyeong Yeon; Kim, Jong Bum; Koo, Gyeong Hoi; Ham, Chang Shik; Kwon, Kee Choon; Kim, Jung Taek; Park, Jae Chang; Lee, Jung Woon; Lee, Yong Hee; Kim, Chang Hwoi; Sim, Bong Shick; Hahn, Do Hee; Choi, Jong Hyeun; Kwon, Sang Woon.

    1997-07-01

    KAERI is working for the development of KALIMER and work is being done for methodology development, experimental facility set up and design concept development. The development target of KALIMER has been set as to make KALIMER safer, more economic, more resistant to nuclear proliferation, and yield less impact on the environment. To achieve the target, study has been made for setting up the design concept of KALIMER including the assessment of various possible design alternatives. This report is the results of the study for the KALIMER concept study and describes the design concept of KALIMER. The developed design concept study and describes the design concept of KALIMER. The developed design concept is to be used as the starting point of the next development phase of conceptual design and the concept will be refined and modified in the conceptual design phase. The scope of the work has been set as the NSSS and essential BOP systems. For systems, NSSS and functionally related major BOP are covered. Sizing and specifying conceptual structure are covered for major equipment. Equipment and piping are arranged for the parts where the arrangement is critical in fulfilling the foresaid intention of setting up the KALIMER design concept. This report consists of 10 chapters. Chapter 2 is for the top level design requirements of KALIMER and it serves as the basis of KALIMER design concept development. Chapter 3 summarizes the KALIMER concept and describes the general design features. The remaining chapters are for specific systems. (author). 29 tabs., 37 figs

  19. Designing the design at JPL'S innovation foundary

    Science.gov (United States)

    Balint, Tibor S.; Freeman, Anthony

    2017-08-01

    NASA is a dynamic and living organization. Looking at it through the optics of cybernetics, we can describe it as an autopoietic system. It has to sustain itself, and compete successfully to be viable. Its organizational elements have to interact with the broader environment by maintaining and improving its processes that generate the means for future sustainability. It also needs to bring up follow-on generations who are not simply aligning with the status quo, but also improve the system's viability. For government-run programs, organizational, programmatic and project management practices are often rigidly linear. They can be characterized as observed first-order cybernetic systems, where the paradigm is bound by well-established requirements. At the implementation level this does not readily accommodate flexibility and change. To address this, broadening the system's worldview is needed from the strategic level. This corresponds to an observing second-order cybernetic system, where strategic leadership can overwrite the rules of a first-order system. Changing the worldview of an organization can be complex and face much resistance. Still, with the appropriate strategic-level support, it can be achieved by introducing novel languages, new perspectives, and adding new disciplines to existing ones. In effect, this helps to broaden the organizational paradigm, and subsequently influence its mission, impact the culture, and open up its core processes. These changes can be effectively introduced through design conversations in the early formulation stages, when new ideas are conceived. Within NASA's Jet Propulsion Laboratory, early-stage concept developments are performed at a specially formulated environment, called the Innovation Foundry. Within this office, a continuous effort is being made on designing the design processes, which helps to broaden the variety of the option trades. It is achieved by an added focus on conversations and the inclusion of non

  20. Optimum study designs.

    Science.gov (United States)

    Gu, C; Rao, D C

    2001-01-01

    Because simplistic designs will lead to prohibitively large sample sizes, the optimization of genetic study designs is critical for successfully mapping genes for complex diseases. Creative designs are necessary for detecting and amplifying the usually weak signals for complex traits. Two important outcomes of a study design--power and resolution--are implicitly tied together by the principle of uncertainty. Overemphasis on either one may lead to suboptimal designs. To achieve optimality for a particular study, therefore, practical measures such as cost-effectiveness must be used to strike a balance between power and resolution. In this light, the myriad of factors involved in study design can be checked for their effects on the ultimate outcomes, and the popular existing designs can be sorted into building blocks that may be useful for particular situations. It is hoped that imaginative construction of novel designs using such building blocks will lead to enhanced efficiency in finding genes for complex human traits.

  1. Clothing Systems Design Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Clothing Systems Design Lab houses facilities for the design and rapid prototyping of military protective apparel.Other focuses include: creation of patterns and...

  2. Prestressed concrete design

    CERN Document Server

    Hurst, MK

    1998-01-01

    This edition provides up-to-date guidance on the detailed design of prestressed concrete structures. All major topics are dealt with, including prestressed flat slabs, an important and growing application in the design of buildings.

  3. Algebraic design theory

    CERN Document Server

    Launey, Warwick De

    2011-01-01

    Combinatorial design theory is a source of simply stated, concrete, yet difficult discrete problems, with the Hadamard conjecture being a prime example. It has become clear that many of these problems are essentially algebraic in nature. This book provides a unified vision of the algebraic themes which have developed so far in design theory. These include the applications in design theory of matrix algebra, the automorphism group and its regular subgroups, the composition of smaller designs to make larger designs, and the connection between designs with regular group actions and solutions to group ring equations. Everything is explained at an elementary level in terms of orthogonality sets and pairwise combinatorial designs--new and simple combinatorial notions which cover many of the commonly studied designs. Particular attention is paid to how the main themes apply in the important new context of cocyclic development. Indeed, this book contains a comprehensive account of cocyclic Hadamard matrices. The book...

  4. Food packaging design

    NARCIS (Netherlands)

    Dekker, M.

    2007-01-01

    'Food product design - An integrated approach' deals with food product design from a technological perspective. It presents creative techniques for the innovation process and structured methodologies to translate consumer wishes into product properties based on Quality Function Deployment.

  5. Design reliability engineering

    International Nuclear Information System (INIS)

    Buden, D.; Hunt, R.N.M.

    1989-01-01

    Improved design techniques are needed to achieve high reliability at minimum cost. This is especially true of space systems where lifetimes of many years without maintenance are needed and severe mass limitations exist. Reliability must be designed into these systems from the start. Techniques are now being explored to structure a formal design process that will be more complete and less expensive. The intent is to integrate the best features of design, reliability analysis, and expert systems to design highly reliable systems to meet stressing needs. Taken into account are the large uncertainties that exist in materials, design models, and fabrication techniques. Expert systems are a convenient method to integrate into the design process a complete definition of all elements that should be considered and an opportunity to integrate the design process with reliability, safety, test engineering, maintenance and operator training. 1 fig

  6. Adaptive Trajectory Design

    Data.gov (United States)

    National Aeronautics and Space Administration — Adaptive Trajectory Design (ATD) is an original concept for quick and efficient end-to-end trajectory designs using proven piece-wise dynamical methods. With ongoing...

  7. Participatory Design with Dyslectics

    DEFF Research Database (Denmark)

    Vangeli, Panagiota; Stage, Jan

    2017-01-01

    Participatory Design has been used successfully in many projects but the question is how participatory design works with people with a cognitive disorder like dyslexia. In this study, we analyzed observations of participatory design sessions with dyslectic participants for developing designs...... of a reading software application by applying two participatory design methods: the IDEAS and CI methods. Furthermore, we conducted online surveys to gather information on dyslectics participants’ and their special-education teachers’ opinion regarding the participatory design process, methods and final...... designs. The results indicate that participatory design works effectively with dyslectic people provided the participation of Proxy Users to represent dyslectics, when it is necessary, the participation of an experienced on dyslexia facilitator who has the knowledge to address incidents caused due...

  8. Designing an Educational Game

    DEFF Research Database (Denmark)

    Bjørner, Thomas; Hansen, Charina Benedikte Søgaard

    2010-01-01

    When designing games with learning purposes used in a classroom, there often occur problems about the lack of learning content or the lack of game contents. Other disadvantages of existing educational games are the difficulty to provide a continual balance between the challenge and the pupils......’ skill to control and solve the given task. In this paper we suggest three different perspectives that need to be communicated across in order to design a useful educational game: teachers, pupils and game designers. It is our intention with this paper to suggest some design principles for educational...... games, and to integrate teachers, pupils and game designers needs and requirements. To set up these design principles for educational games we have used a holistic perspective. This means that the design principles must be seen in coherence within the social and physical environment. The design...

  9. Photonic Design for Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Kosten, E.; Callahan, D.; Horowitz, K.; Pala, R.; Atwater, H.

    2014-08-28

    We describe photonic design approaches for silicon photovoltaics including i) trapezoidal broadband light trapping structures ii) broadband light trapping with photonic crystal superlattices iii) III-V/Si nanowire arrays designed for broadband light trapping.

  10. Fusion reactor design studies

    International Nuclear Information System (INIS)

    Emmert, G.A.; Kulcinski, G.L.; Santarius, J.F.

    1990-01-01

    This report discusses the following topics on the ARIES tokamak: systems; plasma power balance; impurity control and fusion ash removal; fusion product ripple loss; energy conversion; reactor fueling; first wall design; shield design; reactor safety; and fuel cost and resources

  11. Designing Human Technologies

    DEFF Research Database (Denmark)

    Simonsen, Jesper

    and the design process, in ethical and society-related concerns, and in evaluating how designs fulfill needs and solve problems. Designing Human Technologies subscribes to a broad technology concept including information and communication, mobile, environmental/sustainable and energy technologies......Design is increasingly becoming a part of the university curriculum and research agenda. The keynote present and discuss Designing Human Technologies – an initiative aiming at establishing a design oriented main subject area alongside traditional main subject areas such as Natural Science......, the Humanities, and Social Science. The initiative broadens the perspective of IS and recognize reflections on aesthetics, ethics, values, connections to politics, and strategies for enabling a better future as legitimate parts of the research agenda. Designing Human Technologies is a design-oriented Strategic...

  12. Energy design for architects

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, A. (ed.)

    1989-01-01

    This book contains techniques for energy efficiency in architectural design. Many aspects are covered including: cost; comfort and health; energy use; the design process; and analytical techniques. 202 figs. (JF)

  13. Rock Slope Design Criteria

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary : rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, : and siltstones ...

  14. Geometric Design Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Geometric Design Laboratory (GDL) is to support the Office of Safety Research and Development in research related to the geometric design...

  15. DMS message design workshops.

    Science.gov (United States)

    2009-03-01

    This report summarizes the training conducted statewide regarding the design and display of messages on : dynamic message signs. The training is based on the Dynamic Message Sign Message Design and Display : Manual (0-4023-P3). Researchers developed ...

  16. Berm Breakwater Design

    DEFF Research Database (Denmark)

    Hald, Tue; Frigaard, Peter; Burcharth, H. F.

    1996-01-01

    Traditionally, conventional rubble mound breakwaters are designed with stable armour units, and consequently, very large stones or even artificial armour units are required. Reshaping breakwater designs allow reshaping of the seward slope thus involving stone movements. Ultimately, dependent...

  17. Learning Design Tools

    NARCIS (Netherlands)

    Griffiths, David; Blat, Josep; Garcia, Rocío; Vogten, Hubert; Kwong, KL

    2005-01-01

    Griffiths, D., Blat, J., Garcia, R., Vogten, H. & Kwong, KL. (2005). Learning Design Tools. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 109-136). Berlin-Heidelberg: Springer Verlag.

  18. Method card design dimensions

    DEFF Research Database (Denmark)

    Wölfel, Christiane; Merritt, T.

    2013-01-01

    There are many examples of cards used to assist or provide structure to the design process, yet there has not been a thorough articulation of the strengths and weaknesses of the various examples. We review eighteen card-based design tools in order to understand how they might benefit designers....... The card-based tools are explained in terms of five design dimensions including the intended purpose and scope of use, duration of use, methodology, customization, and formal/material qualities. Our analysis suggests three design patterns or archetypes for existing card-based design method tools...... and highlights unexplored areas in the design space. The paper concludes with recommendations for the future development of card-based methods for the field of interaction design....

  19. Performing Performance Design Anglonationally

    DEFF Research Database (Denmark)

    2016-01-01

    Video recording of pecha kucha style bricolage aural enactment of an international version of performance design......Video recording of pecha kucha style bricolage aural enactment of an international version of performance design...

  20. Optical system design

    CERN Document Server

    Fischer, Robert F

    2008-01-01

    Honed for more than 20 years in an SPIE professional course taught by renowned optical systems designer Robert E. Fischer, Optical System Design, Second Edition brings you the latest cutting-edge design techniques and more than 400 detailed diagrams that clearly illustrate every major procedure in optical design. This thoroughly updated resource helps you work better and faster with computer-aided optical design techniques, diffractive optics, and the latest applications, including digital imaging, telecommunications, and machine vision. No need for complex, unnecessary mathematical derivations-instead, you get hundreds of examples that break the techniques down into understandable steps. For twenty-first century optical design without the mystery, the authoritative Optical Systems Design, Second Edition features: Computer-aided design use explained through sample problems Case studies of third-millennium applications in digital imaging, sensors, lasers, machine vision, and more New chapters on optomechanic...

  1. Dwelling with design

    OpenAIRE

    Paavilainen, Heidi

    2013-01-01

    Dwelling with Design offers a throughout look at the domestic meanings of design. The research is based on studying households in and around Helsinki, in order to find out what role, if any, design plays in the domestication of a product. The picture emerging from the research is quite different from design’s public and professional image represented for example in the interior decoration magazines, where designed qualities such as usability, reliability, interesting branding and aesthetic co...

  2. Participatory design based research

    DEFF Research Database (Denmark)

    Dau, Susanne; Bach Jensen, Louise; Falk, Lars

    This poster reveal how participatory design based research by the use of a CoED inspired creative process can be used for designing solutions to problems regarding students study activities outside campus.......This poster reveal how participatory design based research by the use of a CoED inspired creative process can be used for designing solutions to problems regarding students study activities outside campus....

  3. Designing information systems

    CERN Document Server

    Blethyn, Stanley G

    2014-01-01

    Designing Information Systems focuses on the processes, methodologies, and approaches involved in designing information systems. The book first describes systems, management and control, and how to design information systems. Discussions focus on documents produced from the functional construction function, users, operators, analysts, programmers and others, process management and control, levels of management, open systems, design of management information systems, and business system description, partitioning, and leveling. The text then takes a look at functional specification and functiona

  4. Design for Disassembly

    DEFF Research Database (Denmark)

    Beim, Anne

    2018-01-01

    Design for Disassembly’ is becoming a familiar part of discourses on environmental strategies for construction and sustainable design. The concept originates in industrial design and pertains to a wide range of strategies for reuse and recycling, all of which highlight a whole-of-life approach t...... to materials and buildings. Design for Disassembly is particularly relevant to prefabricated and industrialized construction; as such methodologies already contain within them the possibility for easy deconstruction, whether for maintenance, refurbishment or reuse....

  5. Job and Work Design

    OpenAIRE

    Van den Broeck, Anja; Parker, Sharon K.

    2017-01-01

    Job design or work design refers to the content, structure, and organization of tasks and activities. It is mostly studied in terms of job characteristics, such as autonomy, workload, role problems, and feedback. Throughout history, job design has moved away from a sole focus on efficiency and productivity to more motivational job designs, including the social approach toward work, Herzberg’s two-factor model, Hackman and Oldham’s job characteristics model, the job demand control model of Kar...

  6. Designing for Interaction Proxemics

    DEFF Research Database (Denmark)

    Grønbæk, Jens Emil

    2018-01-01

    Design of interactive technology provides opportunities as well as constraints in how a group of users can organize in a shared space. The core argument of interaction proxemics is to consider this in designing for collaboration. In my thesis, I focus on conceptualizing design of ubicomp...

  7. Information Design Theories

    Science.gov (United States)

    Pettersson, Rune

    2014-01-01

    Information design has practical and theoretical components. As an academic discipline we may view information design as a combined discipline, a practical theory, or as a theoretical practice. So far information design has incorporated facts, influences, methods, practices, principles, processes, strategies, and tools from a large number of…

  8. Designing for social cohesion

    NARCIS (Netherlands)

    Hummels, C.C.M.; Trotto, A.

    2013-01-01

    The concepts that helps us to get grip on how we make sense of the world or the way we give meaning to our lives is essential for the field of design, since designers produce proposals for action and experience through their designed artefacts. They create opportunities through which a person can

  9. Bayesian Geostatistical Design

    DEFF Research Database (Denmark)

    Diggle, Peter; Lophaven, Søren Nymand

    2006-01-01

    locations to, or deletion of locations from, an existing design, and prospective design, which consists of choosing positions for a new set of sampling locations. We propose a Bayesian design criterion which focuses on the goal of efficient spatial prediction whilst allowing for the fact that model...

  10. DesignLAK17

    DEFF Research Database (Denmark)

    Ringtved, Ulla; Milligan, Sandra; Corrin, Linda

    2017-01-01

    Notions of what constitutes quality in design in traditional on-campus or online teaching and learning may not always translate into scaled digital environments. The DesignLAK17 workshop builds on the DesignLAK16 workshop to explore one aspect of this theme, namely the opportunities arising from...

  11. Lehigh Design Course

    Science.gov (United States)

    Grassi, Vincent G.; Luyben, William L.; Silebi, Cesar A.

    2011-01-01

    This paper discusses a two-semester senior design course that combines traditional steady-state economic process design with dynamic plantwide control. This unique course has been taught at Lehigh for more than a decade and has garnered rave reviews from students, industry, and ABET. Each student design group has its own industrial consultant who…

  12. DEEP EMPATHIC DESIGN

    Directory of Open Access Journals (Sweden)

    FRAQUELLI Roberto

    2015-06-01

    Full Text Available Empathic design is often described as a creative process that translates observations - typically of people and their behaviours into design ideas. Another similar and closely related expression is user centred design, which attempts to turn the attention away from an object or product towards its usefulness and usability. The central premise of empathic design is that the best-designed products and services result from understanding the needs of the people who will use them. User-centred designers engage actively with end-users to gather insights that drive design from the earliest stages of product and service development, right through the design process.[1] Our standard definitions and understanding of empathic design or user centred design are well recognised and widely practiced, particularly taught in design schools and in professional creative business. This paper extends and explores a deeper understanding of empathy within a systems thinking framework where the observer and subject are both components of empathic design. It proposes that empathy can be described as the bonds of connection with others (in its traditional interpretation, but also with an ecological, social and economic context.

  13. Mechatronic Design Automation

    DEFF Research Database (Denmark)

    Fan, Zhun

    successfully design analogue filters, vibration absorbers, micro-electro-mechanical systems, and vehicle suspension systems, all in an automatic or semi-automatic way. It also investigates the very important issue of co-designing plant-structures and dynamic controllers in automated design of Mechatronic...

  14. Designing synthetic biology.

    Science.gov (United States)

    Agapakis, Christina M

    2014-03-21

    Synthetic biology is frequently defined as the application of engineering design principles to biology. Such principles are intended to streamline the practice of biological engineering, to shorten the time required to design, build, and test synthetic gene networks. This streamlining of iterative design cycles can facilitate the future construction of biological systems for a range of applications in the production of fuels, foods, materials, and medicines. The promise of these potential applications as well as the emphasis on design has prompted critical reflection on synthetic biology from design theorists and practicing designers from many fields, who can bring valuable perspectives to the discipline. While interdisciplinary connections between biologists and engineers have built synthetic biology via the science and the technology of biology, interdisciplinary collaboration with artists, designers, and social theorists can provide insight on the connections between technology and society. Such collaborations can open up new avenues and new principles for research and design, as well as shed new light on the challenging context-dependence-both biological and social-that face living technologies at many scales. This review is inspired by the session titled "Design and Synthetic Biology: Connecting People and Technology" at Synthetic Biology 6.0 and covers a range of literature on design practice in synthetic biology and beyond. Critical engagement with how design is used to shape the discipline opens up new possibilities for how we might design the future of synthetic biology.

  15. Conceptual thermal design

    NARCIS (Netherlands)

    Strijk, R.

    2008-01-01

    Present thermal design tools and methods insufficiently support the development of structural concepts engaged by typical practicing designers. Research described in this thesis identifies the main thermal design problems in practice. In addition, models and methods are developed that support an

  16. Total design of participation

    DEFF Research Database (Denmark)

    Munch, Anders V.

    2016-01-01

    The idea of design as an art made not only for the people, but also by the people is an old dream going back at least to William Morris. It is, however, reappearing vigoriously in many kinds of design activism and grows out of the visions of a Total Design of society. The ideas of participation b...

  17. Embodied Design Ideation methods

    DEFF Research Database (Denmark)

    Wilde, Danielle; Vallgårda, Anna; Tomico, Oscar

    2017-01-01

    Embodied design ideation practices work with relationships between body, material and context to enliven design and research potential. Methods are often idiosyncratic and – due to their physical nature – not easily transferred. This presents challenges for designers wishing to develop and share ...

  18. Designing Online Education Courses.

    Science.gov (United States)

    Trentin, Guglielmo

    2001-01-01

    Focuses on the main elements that characterize online course design. Topics include design constraints; analysis of learning needs; defining objectives; course prerequisites; content structuring; course flexibility; learning strategies; evaluation criteria; course activities; course structure; communication architecture; and design evaluation.…

  19. Cryogenic moderator design

    International Nuclear Information System (INIS)

    Diplock, B.R.

    1983-01-01

    This paper describes the present design of the two cold moderators to be built for the Spallation Neutron Source. It discusses the reasons behind a number of the design features and highlights several problem areas requiring solutions before a final design can be constructed

  20. Designers in Britain 7.

    Science.gov (United States)

    New York Graphic Society, Greenwich, CT.

    The Society of Industrial Artists and Designers (SIAD) has for over 40 years been working to establish design as a profession with a status equivalent to that of architecture or engineering. Intended as a selective review of recent British illustration and design in industry, advertising, and publishing, this volume is the seventh in a series…

  1. Designers Block 2002

    DEFF Research Database (Denmark)

    Dickson, Thomas

    2002-01-01

    Artiklen indleder med: ved siden aaf Londons etablerede designmesse '100% Design', er der vokset et undergrundsmiljø af designudstillinger op. Det dominerende og mest kendte initiativ er Designers Block, der i år udstillede to steder i byen. Designers Block er et mere uformelt udstillingsforum...

  2. Prototyping Design and Business

    DEFF Research Database (Denmark)

    Rasmussen, Jørgen; Kramp, Gunnar; Schiønning Mortensen, Bo

    2011-01-01

    It is increasingly common that design firms go from working with their client’s development department on specific products, to discussing strategic issues directly with the company’s management. In this new territory designers face a number of challenges. Designers are traditionally trained to ‘...

  3. Situating universal design architecture: designing with whom?

    Science.gov (United States)

    Jones, Paul

    2014-01-01

    To respond to growing calls for a theoretical unpacking of Universal Design (UD), a disparate movement cohering around attempts to design spaces and technologies that seek to allow use by all people (to the fullest extent possible). The on-going embedding of UD into architectural practice and pedagogy represents an opportune juncture at which to draw learning from other distinct-but-related transformatory architectural movements. Sociological-theoretical commentary. UD has to date, and necessarily, been dominated by the practice contexts from which it emerged. Appealing as a short-hand for description of "designing-for-all", in most cases UD has come to stand in as a term to signal a general intent in this direction and as an umbrella term for the range of technical design resources that have been developed under these auspices. There remains a fundamental ambivalence vis-à-vis the question of users' power/capacity to influence decision-making in the design process in UD; technically-oriented typologies of bodies predominate in influential UD architectural accounts. UD represents rich technical and pedagogical resources for those architects committed to transforming the existing built environment so as to be less hostile to a wide range of users. However, within UD, unpacking the social role of the professional architect vis-à-vis a variety of publics is an important, but hitherto underdeveloped, challenge; issues concerning professional-citizen power relations continue to animate parallel architectural politics, and UD can both contribute and draw much from these on-going explorations. Implications for Rehabilitation Universal Design (UD) architecture shares a close affinity with rehabilitation practice, with the creation of built environments that allow use by individuals with a wide range of capacities a priority for both. While an effective communicative "bridge" between professions, UD's deployment typically leaves unspoken the capacity of users to

  4. Enhanced Design Alternative I: Low Temperature Design

    International Nuclear Information System (INIS)

    MacNeil, K.

    1999-01-01

    The purpose of this document is to evaluate Enhanced Design Alternative (EDA) 1, the low temperature repository design concept (CRWMS M and O 1999a). This technical document will provide supporting information for Site Recommendation (SR) and License Application (LA). Preparation of this evaluation will be in accordance with the technical document preparation plan (TDPP), (CRWMS M and O 1999b). EDA 1, one of five EDAs, was evolved from evaluation of a series of design features and alternatives developed during the first phase of the License Application Design Selection (LADS) process. Low, medium, and high temperature concepts were developed from the design features and alternatives prepared during Phase 1 of the LADS effort (CRWMS M and O 1999a). EDA 1 will first be evaluated against a single Screening Criterion, outlined in CRWMS M and O 1999a, which addresses post-closure performance of the repository. The performance of the repository is defined quantitatively as the peak radiological dose rate to an average individual of a critical group at a distance of 20 km from the repository site within 10,000 years. To satisfy this criterion the peak dose rate must not exceed the anticipated regulatory level of 25 mrem/yr within 10,000 years. If the EDA meets the screening criterion, the EDA will be further evaluated against the LADS Phase 2 Evaluation Criteria contained in CRWMS M and O 1999a

  5. Tribology in machine design

    CERN Document Server

    Stolarski, Tadeusz

    1999-01-01

    ""Tribology in Machine Design is strongly recommended for machine designers, and engineers and scientists interested in tribology. It should be in the engineering library of companies producing mechanical equipment.""Applied Mechanics ReviewTribology in Machine Design explains the role of tribology in the design of machine elements. It shows how algorithms developed from the basic principles of tribology can be used in a range of practical applications within mechanical devices and systems.The computer offers today's designer the possibility of greater stringen

  6. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  7. Integrated Structural Design Education

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    2011-01-01

    to EU legislation. And a successful engineering student must be prepared to work in the open-ended, multidisciplinary environment necessary to produce structures which comply with EIA demands. This paper describes an innovative course developed at the Technical University of Denmark which integrates...... landscaping and structural design. The integrated courses create a setting for learning about the design of large-scale structures and involve geometry, statics, computer simulation, graphical design and landscape architecture. Together, they educate engineers who can take part in the early design phases...... of a project, function well in design teams, and comply with EU EIA demands....

  8. Learning Space Service Design

    Directory of Open Access Journals (Sweden)

    Elliot Felix

    2011-12-01

    Full Text Available Much progress has been made in creating informal learning spaces that incorporate technology and flexibly support a variety of activities. This progress has been principally in designing the right combination of furniture, technology, and space. However, colleges and universities do not design services within learning spaces with nearly the same level of sophistication or integration. Nor do they adequately assess their services. This paper calls for a focus on designing services to facilitate better learning experiences. It describes the fundamentals of service design practice, a selection of exemplary spaces, and the implications for design, budgeting, and staffing.

  9. Interior design for dentistry.

    Science.gov (United States)

    Unthank, M; True, G

    1999-11-01

    In the increasingly complex, competitive and stressful field of dentistry, effectively designed dental offices can offer significant benefits. Esthetic, functional and life-cycle cost issues to be considered when developing your interior design scheme include color, finishes, lighting, furnishings, art and accessories. An appropriately designed dental office serves as a valuable marketing tool for your practice, as well as a safe and enjoyable work environment. Qualified interior design professionals can help you make design decisions that can yield optimum results within your budget.

  10. Exemplary Design Practice

    DEFF Research Database (Denmark)

    Jørgensen, Niels

    The didactic principle of exemplary learning may be defined briefly as 'learning by example'. In design education, working with a practical example is particularly appropriate, because design by definition is about creating a solution to a practical problem. Indeed, some design theorists claim......, including: If design knowing is bound to a given practical design context, how is it possible to generalize such knowing, as presumably required by an exemplary learning approach? To explore these questions, an account is given of the theories of exemplary learning proposed by Martin Wagenschein and Oskar...

  11. MOS integrated circuit design

    CERN Document Server

    Wolfendale, E

    2013-01-01

    MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi

  12. Maintainability design guide

    International Nuclear Information System (INIS)

    Pack, R.W.

    1985-01-01

    The Human Factors Design Guide for Maintainability provides guidance for systematically incorporating good human factors techniques into the design of power plants. The guide describes a means of developing a comprehensive program plan to ensure compliance with the human factors approaches specified by the utility. The guide also provides specific recommendations for design practices, with examples, bases, and references. The recommendations are formatted for easy use by nuclear power plant design teams and by utility personnel involved in specification and design review. The guide was developed under EPRI research project RP2166-4 and is currently being published

  13. Towards programmatic design research

    Directory of Open Access Journals (Sweden)

    Jonas Löwgren

    2013-12-01

    Full Text Available The notion of design research entails research where design practice forms part of the knowledge production. Based on our characterization of the nature of design, we propose to conceptualize this kind of research as programmatic design research. Two ongoing PhD projects in interaction design are presented as examples of programmatic research processes, highlighting issues to do with the virtues and qualities of the processes, the interplay of optics and engagements in a hermeneutical dynamic, and the production of takeaways for the academic community.

  14. Worldviews for Design Theory

    DEFF Research Database (Denmark)

    Galle, Per

    2006-01-01

    aware of, I demonstrate how 'insidious inconsistency ' may infect design theory if we ignore this admonition. As a possible remedy, I propose a method by which the philosophy of design may develop sound methaphysical foundations ('worldviews') for design theory - and obtain philosophical insights......I suspect that the growing 'body' of design theory may be infected by more inconsistency than is justifiable by genuine disagreement among design researchers. Taking my clue from Peirce, who argued that theory inevitably rests on basics metaphysical assumptions that theorists ought to be critically...

  15. Design Characteristics as Basis for Design Languages

    DEFF Research Database (Denmark)

    Mortensen, Niels Henrik

    1997-01-01

    The application of modern feature based CAD systems has in many companies lead to significant rationalisation of design, particulary the "down stream" acticities such as NC code generation, FEM analysis, mould flow simulation and documentation. The subject of this paper is the "up stream" activit......The application of modern feature based CAD systems has in many companies lead to significant rationalisation of design, particulary the "down stream" acticities such as NC code generation, FEM analysis, mould flow simulation and documentation. The subject of this paper is the "up stream...

  16. Scandinavian Participatory Design - Beyond Design, Beyond Scandinavia

    DEFF Research Database (Denmark)

    Zander, Pär-Ola; Georgsen, Marianne; Nyvang, Tom

    2011-01-01

    This paper presents a stream of research that is relevant for development research generally and also in South Asia, but has hitherto remained outside the discourse of mainstream development research. It goes under the name "Participatory design", referring not only generally to participatory...... approaches, of which there are many in development research, but to a specific body of work that stems from Scandinavia. Within the research fields relating to design of ICT systems the Scandinavian countries have a rich history of incorporating disadvantaged groups in societies. This paper argues...

  17. Empathic design: Research strategies

    Directory of Open Access Journals (Sweden)

    Joyce Thomas

    2013-01-01

    Full Text Available This paper explores the role of empathy within new product development from the perspective of human-centred design. The authors have developed a range of empathic design tools and strategies that help to identify authentic human needs.For products and services to be effective, they need to satisfy both functional and emotional needs of individuals. In addition, the individual user needs to feel that the product and/or service has been designed ‘just for them’, otherwise they may misuse, underuse or abandon the product/service. This becomes critical with a product such as a Zimmer frame (walker, when it fails to resonate with the patient due to any stigma the patient may perceive, and thus remains unused.When training young designers to consider the wider community (people unlike themselves during the design process, it has proven extremely valuable to take them outside their comfort zones, by seeking to develop empathy with the end user for whom they are designing. Empathic modelling offers designers the opportunity to develop greater insight and understanding, in order to support more effective design outcomes. Sensitising designers to the different ways that individuals complete daily tasks has helped to diminish the gap between themselves and others (e.g. people with disabilities.The authors intend for this paper to resonate with health care providers. Human-centred design can help to refocus the designer, by placing the individual end user’s needs at the heart of their decision-making.

  18. Empathic design: Research strategies.

    Science.gov (United States)

    Thomas, Joyce; McDonagh, Deana

    2013-01-01

    This paper explores the role of empathy within new product development from the perspective of human-centred design. The authors have developed a range of empathic design tools and strategies that help to identify authentic human needs.For products and services to be effective, they need to satisfy both functional and emotional needs of individuals. In addition, the individual user needs to feel that the product and/or service has been designed 'just for them', otherwise they may misuse, underuse or abandon the product/service. This becomes critical with a product such as a Zimmer frame (walker), when it fails to resonate with the patient due to any stigma the patient may perceive, and thus remains unused.When training young designers to consider the wider community (people unlike themselves) during the design process, it has proven extremely valuable to take them outside their comfort zones, by seeking to develop empathy with the end user for whom they are designing. Empathic modelling offers designers the opportunity to develop greater insight and understanding, in order to support more effective design outcomes. Sensitising designers to the different ways that individuals complete daily tasks has helped to diminish the gap between themselves and others (e.g. people with disabilities).The authors intend for this paper to resonate with health care providers. Human-centred design can help to refocus the designer, by placing the individual end user's needs at the heart of their decision-making.

  19. Reactor System Design

    International Nuclear Information System (INIS)

    Chi, S. K.; Kim, G. K.; Yeo, J. W.

    2006-08-01

    SMART NPP(Nuclear Power Plant) has been developed for duel purpose, electricity generation and energy supply for seawater desalination. The objective of this project IS to design the reactor system of SMART pilot plant(SMART-P) which will be built and operated for the integrated technology verification of SMART. SMART-P is an integral reactor in which primary components of reactor coolant system are enclosed in single pressure vessel without connecting pipes. The major components installed within a vessel includes a core, twelve steam generator cassettes, a low-temperature self pressurizer, twelve control rod drives, and two main coolant pumps. SMART-P reactor system design was categorized to the reactor coe design, fluid system design, reactor mechanical design, major component design and MMIS design. Reactor safety -analysis and performance analysis were performed for developed SMART=P reactor system. Also, the preparation of safety analysis report, and the technical support for licensing acquisition are performed

  20. LISA system design highlights

    Energy Technology Data Exchange (ETDEWEB)

    Sallusti, M [European Space Agency, ESTEC, Keplerlaan 1, 2200 AG Noordwijk ZH (Netherlands); Gath, P; Weise, D; Berger, M; Schulte, H R, E-mail: marcello.sallusti@esa.in, E-mail: peter.gath@astrium.eads.ne, E-mail: dennis.weise@astrium.eads.ne, E-mail: marcel.berger@astrium.eads.ne, E-mail: Hans.Reiner.Schulte@astrium.eads.ne [Astrium GmbH Satellites, Claude-Dornier-Str., 88039 Friedrichshafen (Germany)

    2009-05-07

    A contract, started in January 2005, was awarded to a consortium of Astrium GmbH and Astrium Ltd for the LISA Mission Formulation. The scope of the contract was the development of a reference design for the mission architecture and for the mission elements (with particular focus on the payload) and a successive phase of derivation of requirements, to be concluded with a mission design review. The technical starting point was the output of the previous LISA study formalized in the Final Technical Report, issued in the year 2000. During the design phase, different architecture concepts were identified and traded off, including the LISA orbits, the measurement scheme and the opto-mechanical architecture. During the Mission Design Review (July 2008) the consolidated mission baseline design, and the specifications of the flight elements and of the payload subsystem and major components were presented. This paper gives a brief overview of the major design points of the latest design of the LISA system.

  1. LISA system design highlights

    International Nuclear Information System (INIS)

    Sallusti, M; Gath, P; Weise, D; Berger, M; Schulte, H R

    2009-01-01

    A contract, started in January 2005, was awarded to a consortium of Astrium GmbH and Astrium Ltd for the LISA Mission Formulation. The scope of the contract was the development of a reference design for the mission architecture and for the mission elements (with particular focus on the payload) and a successive phase of derivation of requirements, to be concluded with a mission design review. The technical starting point was the output of the previous LISA study formalized in the Final Technical Report, issued in the year 2000. During the design phase, different architecture concepts were identified and traded off, including the LISA orbits, the measurement scheme and the opto-mechanical architecture. During the Mission Design Review (July 2008) the consolidated mission baseline design, and the specifications of the flight elements and of the payload subsystem and major components were presented. This paper gives a brief overview of the major design points of the latest design of the LISA system.

  2. Visualization Design Environment

    Energy Technology Data Exchange (ETDEWEB)

    Pomplun, A.R.; Templet, G.J.; Jortner, J.N.; Friesen, J.A.; Schwegel, J.; Hughes, K.R.

    1999-02-01

    Improvements in the performance and capabilities of computer software and hardware system, combined with advances in Internet technologies, have spurred innovative developments in the area of modeling, simulation and visualization. These developments combine to make it possible to create an environment where engineers can design, prototype, analyze, and visualize components in virtual space, saving the time and expenses incurred during numerous design and prototyping iterations. The Visualization Design Centers located at Sandia National Laboratories are facilities built specifically to promote the ''design by team'' concept. This report focuses on designing, developing and deploying this environment by detailing the design of the facility, software infrastructure and hardware systems that comprise this new visualization design environment and describes case studies that document successful application of this environment.

  3. Teaching engineering design research

    DEFF Research Database (Denmark)

    Blessing, Lucienne; Andreasen, Mogens Myrup

    2005-01-01

    The importance og engineering design as an industrial activity, and the increasingly complex and dynamic context in which it takes place, has led to the wish to improve the effectiveness and efficiency of engineering design in practice as well as in education. Although attempts have been made...... to improve design for centuries, it was not until well in the second half of the 20th century that engineering design became a research topic (see pahl and Beitz (1996), Heymann (2004) for historical overviews). Engineering research, such as research into thermodynamics, mechanics and materials, has a much...... by PhD students. This has created the demand for a clear, efficient way of learning the crafmanship of doing design research, a demand which is in strong contrast to the state of design research in general. This article reflects the authors' efforts in running a summer school om engineering design...

  4. Roller bearing geometry design

    Science.gov (United States)

    Savage, M.; Pinkston, B. H. W.

    1976-01-01

    A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

  5. Ethics and technology design

    DEFF Research Database (Denmark)

    Albrechtslund, Anders

    2007-01-01

    This article offers a discussion of the connection between technology and values and, specifically, I take a closer look at ethically sound design. In order to bring the discussion into a concrete context, the theory of Value Sensitive Design (VSD) will be the focus point. To illustrate my argument...... concerning design ethics, the discussion involves a case study of an augmented window, designed by the VSD Research Lab, which has turned out to be a potentially surveillance-enabling technology. I call attention to a "positivist problem" that has to do with the connection between the design context...... of design ethics, is intended as a constructive criticism, which can hopefully contribute to the further development of design ethics....

  6. Sustainable Housing Design

    DEFF Research Database (Denmark)

    Lauring, Gert Michael

    2016-01-01

    Sustainable Housing Design. Integrating technical and housing quality aspects of sustainable architecture in civil engineering education. Summary An integrated design approach to sustainable architecture is outlined that combines concerns for zero energy building, good indoor climate and adequate...... phases. The outcome shows that integrated design further solutions where sustainable urban forms of settlement can be highly energy efficient while also attractive from a user perspective. Key words: Sustainable architecture, integrated design, zero-energy-housing, dense urban living. 1. Introduction...... When designing sustainable housing, energy optimization and satisfactory indoor climates are central issues that need to be incorporated from early design phases if to reach a coherent design. It might also be argued that the energy consumption of contemporary buildings only plays a rela-tively minor...

  7. Scandinavian Participatory Design

    DEFF Research Database (Denmark)

    Iversen, Ole Sejer; Smith, Rachel Charlotte

    2012-01-01

    As Scandinavian Participatory Design (PD) approach is a highly values-led design approach, and is gaining importance in IDC research, we discuss the underlying values of democracy, quality of work and emancipation of this approach. We present a case study, Digital Natives, in which the Scandinavian...... PD approach was put into practice. Here we involved seven teenagers in the design of an interactive museum exhibition. We discuss how this particular approach effects key design activities such as the establishment of the design space, power relations among participants, the dialogical design process......, project evaluation and the final outcome of the project. We conclude that the end goal of Scandinavian PD is not necessarily the final research prototype. Rather, in Scandinavian PD, designers strive to provide children with meaningful alternatives to existing technologies. It is to help children realize...

  8. Efficient Learning Design

    DEFF Research Database (Denmark)

    Godsk, Mikkel

    This paper presents the current approach to implementing educational technology with learning design at the Faculty of Science and Technology, Aarhus University, by introducing the concept of ‘efficient learning design’. The underlying hypothesis is that implementing learning design is more than...... engaging educators in the design process and developing teaching and learning, it is a shift in educational practice that potentially requires a stakeholder analysis and ultimately a business model for the deployment. What is most important is to balance the institutional, educator, and student...... perspectives and to consider all these in conjunction in order to obtain a sustainable, efficient learning design. The approach to deploying learning design in terms of the concept of efficient learning design, the catalyst for educational development, i.e. the learning design model and how it is being used...

  9. A designated centre for people with disabilities operated by Nua Healthcare Services, Clare

    LENUS (Irish Health Repository)

    Backert, Steffen

    2011-11-01

    Abstract Helicobacter pylori is a highly successful pathogen uniquely adapted to colonize humans. Gastric infections with this bacterium can induce pathology ranging from chronic gastritis and peptic ulcers to gastric cancer. More virulent H. pylori isolates harbour numerous well-known adhesins (BabA\\/B, SabA, AlpA\\/B, OipA and HopZ) and the cag (cytotoxin-associated genes) pathogenicity island encoding a type IV secretion system (T4SS). The adhesins establish tight bacterial contact with host target cells and the T4SS represents a needle-like pilus device for the delivery of effector proteins into host target cells such as CagA. BabA and SabA bind to blood group antigen and sialylated proteins respectively, and a series of T4SS components including CagI, CagL, CagY and CagA have been shown to target the integrin β1 receptor followed by injection of CagA across the host cell membrane. The interaction of CagA with membrane-anchored phosphatidylserine may also play a role in the delivery process. While substantial progress has been made in our current understanding of many of the above factors, the host cell receptors for OipA, HopZ and AlpA\\/B during infection are still unknown. Here we review the recent progress in characterizing the interactions of the various adhesins and structural T4SS proteins with host cell factors. The contribution of these interactions to H. pylori colonization and pathogenesis is discussed.

  10. Is Engineering Design Disappearing from Design Research?

    DEFF Research Database (Denmark)

    Andreasen, Mogens Myrup; Howard, Thomas J.

    2011-01-01

    Most systems and products need to be engineered during their design, based upon scientific insight into principles, mechanisms, materials and production pos-sibilities, leading to reliability, durability and value for the user. Despite the central importance and design’s crucial dependency...

  11. Quality by design approach in the development of an ultra-high-performance liquid chromatography method for Bexsero meningococcal group B vaccine.

    Science.gov (United States)

    Nompari, Luca; Orlandini, Serena; Pasquini, Benedetta; Campa, Cristiana; Rovini, Michele; Del Bubba, Massimo; Furlanetto, Sandra

    2018-02-01

    Bexsero is the first approved vaccine for active immunization of individuals from 2 months of age and older to prevent invasive disease caused by Neisseria meningitidis serogroup B. The active components of the vaccine are Neisseria Heparin Binding Antigen, factor H binding protein, Neisseria adhesin A, produced in Escherichia coli cells by recombinant DNA technology, and Outer Membrane Vesicles (expressing Porin A and Porin B), produced by fermentation of Neisseria meningitidis strain NZ98/254. All the Bexsero active components are adsorbed on aluminum hydroxide and the unadsorbed antigens content is a product critical quality attribute. In this paper the development of a fast, selective and sensitive ultra-high-performance liquid chromatography (UHPLC) method for the determination of the Bexsero antigens in the vaccine supernatant is presented. For the first time in the literature, the Quality by Design (QbD) principles were applied to the development of an analytical method aimed to the quality control of a vaccine product. The UHPLC method was fully developed within the QbD framework, the new paradigm of quality outlined in International Conference on Harmonisation guidelines. Critical method attributes (CMAs) were identified with the capacity factor of Neisseria Heparin Binding Antigen, antigens resolution and peak areas. After a scouting phase, aimed at selecting a suitable and fast UHPLC operative mode for the vaccine antigens separation, risk assessment tools were employed to define the critical method parameters to be considered in the screening phase. Screening designs were applied for investigating at first the effects of vial type and sample concentration, and then the effects of injection volume, column type, organic phase starting concentration, ramp time and temperature. Response Surface Methodology pointed out the presence of several significant interaction effects, and with the support of Monte-Carlo simulations led to map out the design space, at

  12. Future steam generator designs. Single wall designs

    Energy Technology Data Exchange (ETDEWEB)

    Hayden, O [Nuclear Power Company Ltd, Warrington, Cheshire (United Kingdom)

    1978-10-01

    The easily removable 'U' tube design style adopted in the UK for the existing PFR Steam Generators, the Replacement Units now in production and for the future CDFR, gives the operator an extremely valuable option in the event of a water/steam leak occurring inside the Steam Generator. He can choose to shut-down, attempt to find the leak, assess damage, repair, revalidate and return to service in situ, or he can elect to remove the defect unit and replace with a 'proven' spare before returning the circuit to power. With the latter approach the resultant outage time is a known entity of about two weeks. If a repair is attempted in situ, predictions of outage time can become a matter of guesswork since one has no 'guaranteed' method of leak location and the assessment of secondary damage may be very time consuming, depending on the size and type of the original leak together with the particular design style of the Steam Generator. A further significant advantage of the removable 'U' tube design concept is that periodic interchanging of bundles with a spare enables routine chemical cleaning and thorough scheduled tube inspections, with specimen tube sample removal if required for monitoring purposes. If necessary, bundle decontamination can be undertaken to assess engineering deterioration to various degrees of thoroughness ranging from 100% equivalent factory final assembly inspection, to partial decontamination operating via a glovebox type of maintenance bag arrangement, examining local points of both shell and tube areas of the bundle. Many lessons from the last five years' experience of PFR will be incorporated into the design of the CDFR and PFR Steam Generators have two very good examples of how the designer can ease or severely handicap the operator in coping with sodium/water leakages. Good, quick access to tube ends is achieved in the existing PFR Evaporator by simply unbolting the steam/water closure head, but on the superheater and reheater hand-caps have

  13. Future steam generator designs. Single wall designs

    International Nuclear Information System (INIS)

    Hayden, O.

    1978-01-01

    The easily removable 'U' tube design style adopted in the UK for the existing PFR Steam Generators, the Replacement Units now in production and for the future CDFR, gives the operator an extremely valuable option in the event of a water/steam leak occurring inside the Steam Generator. He can choose to shut-down, attempt to find the leak, assess damage, repair, revalidate and return to service in situ, or he can elect to remove the defect unit and replace with a 'proven' spare before returning the circuit to power. With the latter approach the resultant outage time is a known entity of about two weeks. If a repair is attempted in situ, predictions of outage time can become a matter of guesswork since one has no 'guaranteed' method of leak location and the assessment of secondary damage may be very time consuming, depending on the size and type of the original leak together with the particular design style of the Steam Generator. A further significant advantage of the removable 'U' tube design concept is that periodic interchanging of bundles with a spare enables routine chemical cleaning and thorough scheduled tube inspections, with specimen tube sample removal if required for monitoring purposes. If necessary, bundle decontamination can be undertaken to assess engineering deterioration to various degrees of thoroughness ranging from 100% equivalent factory final assembly inspection, to partial decontamination operating via a glovebox type of maintenance bag arrangement, examining local points of both shell and tube areas of the bundle. Many lessons from the last five years' experience of PFR will be incorporated into the design of the CDFR and PFR Steam Generators have two very good examples of how the designer can ease or severely handicap the operator in coping with sodium/water leakages. Good, quick access to tube ends is achieved in the existing PFR Evaporator by simply unbolting the steam/water closure head, but on the superheater and reheater hand-caps have

  14. Designer's unified cost model

    Science.gov (United States)

    Freeman, William T.; Ilcewicz, L. B.; Swanson, G. D.; Gutowski, T.

    1992-01-01

    A conceptual and preliminary designers' cost prediction model has been initiated. The model will provide a technically sound method for evaluating the relative cost of different composite structural designs, fabrication processes, and assembly methods that can be compared to equivalent metallic parts or assemblies. The feasibility of developing cost prediction software in a modular form for interfacing with state of the art preliminary design tools and computer aided design programs is being evaluated. The goal of this task is to establish theoretical cost functions that relate geometric design features to summed material cost and labor content in terms of process mechanics and physics. The output of the designers' present analytical tools will be input for the designers' cost prediction model to provide the designer with a data base and deterministic cost methodology that allows one to trade and synthesize designs with both cost and weight as objective functions for optimization. The approach, goals, plans, and progress is presented for development of COSTADE (Cost Optimization Software for Transport Aircraft Design Evaluation).

  15. Designers' unified cost model

    Science.gov (United States)

    Freeman, W.; Ilcewicz, L.; Swanson, G.; Gutowski, T.

    1992-01-01

    The Structures Technology Program Office (STPO) at NASA LaRC has initiated development of a conceptual and preliminary designers' cost prediction model. The model will provide a technically sound method for evaluating the relative cost of different composite structural designs, fabrication processes, and assembly methods that can be compared to equivalent metallic parts or assemblies. The feasibility of developing cost prediction software in a modular form for interfacing with state-of-the-art preliminary design tools and computer aided design programs is being evaluated. The goal of this task is to establish theoretical cost functions that relate geometric design features to summed material cost and labor content in terms of process mechanics and physics. The output of the designers' present analytical tools will be input for the designers' cost prediction model to provide the designer with a database and deterministic cost methodology that allows one to trade and synthesize designs with both cost and weight as objective functions for optimization. This paper presents the team members, approach, goals, plans, and progress to date for development of COSTADE (Cost Optimization Software for Transport Aircraft Design Evaluation).

  16. Learning for design reuse

    DEFF Research Database (Denmark)

    Duffy, Alex; Duffy, Sandra M.

    1996-01-01

    Over the past decade "design assistance", that is, where the computer is viewed as an Intelligent Design Assistant (IDA), has emerged in knowledge based design support and has formed the basic research strategy for the CAD Cantre, University of Strathclyde, since the mid-1980s. Within this philos......Over the past decade "design assistance", that is, where the computer is viewed as an Intelligent Design Assistant (IDA), has emerged in knowledge based design support and has formed the basic research strategy for the CAD Cantre, University of Strathclyde, since the mid-1980s. Within...... this philosophy, an IDA would act as a colleague to a designer, providing guidance, learning from past experiences, carrying out semi- and fully-automated tasks, explaining its reasoning and in essence complementing the designer's own natural skills, and thus leaving the ultimate decision-making, control......, and responsibility with the designer.The ability to learn and evolve has been recognized as one of the key components of an IDA for it to fully support the designer's activities. Consequently, we have been directing our research effort on two main fronts, formalizing our understanding and developing models...

  17. The design game in Participatory Design and design education

    DEFF Research Database (Denmark)

    Törpel, Bettina

    2006-01-01

    carefully. Cases from student projects are used as illustrating examples; work environments were redesigned and design games played. It turns out that degrees of freedom are present for the choice of (gaming) method as well as the ways of using the selected method. These degrees of freedom should be used...... in a way that will be labeled as »interested«, rather than in a way labeled as »taking for granted«. It is not possible to guarantee an interested and beneficial approach; yet the paper argues on the grounds that reflective gaming practice can be supportive in this direction....

  18. Crystal structure of the Haemophilus influenzae Hap adhesin reveals an intercellular oligomerization mechanism for bacterial aggregation

    Science.gov (United States)

    Meng, Guoyu; Spahich, Nicole; Kenjale, Roma; Waksman, Gabriel; St Geme, Joseph W

    2011-01-01

    Bacterial biofilms are complex microbial communities that are common in nature and are being recognized increasingly as an important determinant of bacterial virulence. However, the structural determinants of bacterial aggregation and eventual biofilm formation have been poorly defined. In Gram-negative bacteria, a major subgroup of extracellular proteins called self-associating autotransporters (SAATs) can mediate cell–cell adhesion and facilitate biofilm formation. In this study, we used the Haemophilus influenzae Hap autotransporter as a prototype SAAT to understand how bacteria associate with each other. The crystal structure of the H. influenzae HapS passenger domain (harbouring the SAAT domain) was determined to 2.2 Å by X-ray crystallography, revealing an unprecedented intercellular oligomerization mechanism for cell–cell interaction. The C-terminal SAAT domain folds into a triangular-prism-like structure that can mediate Hap–Hap dimerization and higher degrees of multimerization through its F1–F2 edge and F2 face. The intercellular multimerization can give rise to massive buried surfaces that are required for overcoming the repulsive force between cells, leading to bacterial cell–cell interaction and formation of complex microcolonies. PMID:21841773

  19. Influence of divalent cations and pH adsorption of a bacterial polysaccharide adhesin

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Suci, P.A.; Baty, A.M.; Weiner, R.M.; Geesey, G.G.

    mg/ml); (bottom) sample dried onto Ge IRE. W, region of strong water absorption at 1640 cm 21 ; T, absorbance from Teflon O-rings of flow chamber; A, composite band used to measure fr2ps adsorption; II, amide II band. Broken lines are to aid the eye... using fluid displacement. Samples were dried overnight in the FT-IR chamber before measurement. FT-IR Spectroscopy During the course of each experiment infrared spectra were acquired periodically using a Perkin-Elmer Model 1800 Fou- rier transform...

  20. Plasmodium falciparum Adhesins Play an Essential Role in Signalling and Activation of Invasion into Human Erythrocytes.

    Directory of Open Access Journals (Sweden)

    Wai-Hong Tham

    2015-12-01

    Full Text Available The most severe form of malaria in humans is caused by the protozoan parasite Plasmodium falciparum. The invasive form of malaria parasites is termed a merozoite and it employs an array of parasite proteins that bind to the host cell to mediate invasion. In Plasmodium falciparum, the erythrocyte binding-like (EBL and reticulocyte binding-like (Rh protein families are responsible for binding to specific erythrocyte receptors for invasion and mediating signalling events that initiate active entry of the malaria parasite. Here we have addressed the role of the cytoplasmic tails of these proteins in activating merozoite invasion after receptor engagement. We show that the cytoplasmic domains of these type 1 membrane proteins are phosphorylated in vitro. Depletion of PfCK2, a kinase implicated to phosphorylate these cytoplasmic tails, blocks P. falciparum invasion of red blood cells. We identify the crucial residues within the PfRh4 cytoplasmic domain that are required for successful parasite invasion. Live cell imaging of merozoites from these transgenic mutants show they attach but do not penetrate erythrocytes implying the PfRh4 cytoplasmic tail conveys signals important for the successful completion of the invasion process.

  1. Structure determination and analysis of a haemolytic gingipain adhesin domain from Porphyromonas gingivalis

    Energy Technology Data Exchange (ETDEWEB)

    Li, N.; Yun, P.; Nadkarni, M.A.; Ghadikolaee, N.B.; Nguyen, K.A.; Lee, M.; Hunter, N.; Collyer, C.A. (Sydney)

    2010-08-27

    Porphyromonas gingivalis is an obligately anaerobic bacterium recognized as an aetiological agent of adult periodontitis. P. gingivalis produces cysteine proteinases, the gingipains. The crystal structure of a domain within the haemagglutinin region of the lysine gingipain (Kgp) is reported here. The domain was named K2 as it is the second of three homologous structural modules in Kgp. The K2 domain structure is a 'jelly-roll' fold with two anti-parallel {beta}-sheets. This fold topology is shared with adhesive domains from functionally diverse receptors such as MAM domains, ephrin receptor ligand binding domains and a number of carbohydrate binding modules. Possible functions of K2 were investigated. K2 induced haemolysis of erythrocytes in a dose-dependent manner that was augmented by the blocking of anion transport. Further, cysteine-activated arginine gingipain RgpB, which degrades glycophorin A, sensitized erythrocytes to the haemolytic effect of K2. Cleaved K2, similar to that found in extracted Kgp, lacks the haemolytic activity indicating that autolysis of Kgp may be a staged process which is artificially enhanced by extraction of the protein. The data indicate a functional role for K2 in the integrated capacity conferred by Kgp to enable the porphyrin auxotroph P. gingivalis to capture essential haem from erythrocytes.

  2. Pyruvate dehydrogenase subunit β of Lactobacillus plantarum is a collagen adhesin involved in biofilm formation.

    Science.gov (United States)

    Salzillo, Marzia; Vastano, Valeria; Capri, Ugo; Muscariello, Lidia; Marasco, Rosangela

    2017-04-01

    Multi-functional surface proteins have been observed in a variety of pathogenic bacteria, where they mediate host cell adhesion and invasion, as well as in commensal bacterial species, were they mediate positive interaction with the host. Among these proteins, some glycolytic enzymes, expressed on the bacterial cell surface, can bind human extracellular matrix components (ECM). A major target for them is collagen, an abundant glycoprotein of connective tissues. We have previously shown that the enolase EnoA1 of Lactobacillus plantarum, one of the most predominant species in the gut microbiota of healthy individuals, is involved in binding with collagen type I (CnI). In this study, we found that PDHB, a component of the pyruvate dehydrogenase complex, contributes to the L. plantarum LM3 adhesion to CnI. By a cellular adhesion assay to immobilized CnI, we show that LM3-B1 cells, carrying a null mutation in the pdhB gene, bind to CnI - coated surfaces less efficiently than wild-type cells. Moreover, we show that the PDHB-CnI interaction requires a native state for PDHB. We also analyzed the ability to develop biofilm in wild-type and mutant strains and we found that the lack of the PDHB on cell surface generates cells partially impaired in biofilm development. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Structure of the Streptococcus pneumoniae Surface Protein and Adhesin PfbA

    OpenAIRE

    Suits, Michael D.; Boraston, Alisdair B.

    2013-01-01

    PfbA (plasmin- and fibronectin-binding protein A) is an extracellular Streptococcus pneumoniae cell-wall attached surface protein that binds to fibronectin, plasmin, and plasminogen. Here we present a structural analysis of the surface exposed domains of PfbA using a combined approach of X-ray crystallography and small-angle X-ray scattering (SAXS). The crystal structure of the PfbA core domain, here called PfbAβ, determined to 2.28 Å resolution revealed an elongated 12-stranded parallel β-he...

  4. Functional characterization of a mucus-specific LPXTG surface adhesin from probiotic Lactobacillus rhamnosus GG

    NARCIS (Netherlands)

    Ossowski, von I.; Vos, de W.M.; Palva, A.

    2011-01-01

    In spite of the wealth of clinical evidence supporting the health benefits of Lactobacillus rhamnosus GG in humans, there is still a lack of understanding of the molecular mechanisms behind its probiosis. Current knowledge suggests that the health-promoting effects of this probiotic strain might be

  5. A genomic region involved in the formation of adhesin fibers in Bacillus cereus biofilms

    Directory of Open Access Journals (Sweden)

    Joaquín eCaro-Astorga

    2015-01-01

    Full Text Available Bacillus cereus is a bacterial pathogen that is responsible for many recurrent disease outbreaks due to food contamination. Spores and biofilms are considered the most important reservoirs of B. cereus in contaminated fresh vegetables and fruits. Biofilms are bacterial communities that are difficult to eradicate from biotic and abiotic surfaces because of their stable and extremely strong extracellular matrix. These extracellular matrixes contain exopolysaccharides, proteins, extracellular DNA, and other minor components. Although B. cereus can form biofilms, the bacterial features governing assembly of the protective extracellular matrix are not known. Using the well-studied bacterium B. subtilis as a model, we identified two genomic loci in B. cereus, which encodes two orthologs of the amyloid-like protein TasA of B. subtilis and a SipW signal peptidase. Deletion of this genomic region in B. cereus inhibited biofilm assembly; notably, mutation of the putative signal peptidase SipW caused the same phenotype. However, mutations in tasA or calY did not completely prevent biofilm formation; strains that were mutated for either of these genes formed phenotypically different surface attached biofilms. Electron microscopy studies revealed that TasA polymerizes to form long and abundant fibers on cell surfaces, whereas CalY does not aggregate similarly. Heterologous expression of this amyloid-like cassette in a B. subtilis strain lacking the factors required for the assembly of TasA amyloid-like fibers revealed i the involvement of this B. cereus genomic region in formation of the air-liquid interphase pellicles and ii the intrinsic ability of TasA to form fibers similar to the amyloid-like fibers produced by its B. subtilis ortholog.

  6. Structural and molecular insights into novel surface-exposed mucus adhesins from Lactobacillus reuteri human strains.

    Science.gov (United States)

    Etzold, Sabrina; MacKenzie, Donald A; Jeffers, Faye; Walshaw, John; Roos, Stefan; Hemmings, Andrew M; Juge, Nathalie

    2014-05-01

    The mucus layer covering the gastrointestinal tract is the first point of contact of the intestinal microbiota with the host. Cell surface macromolecules are critical for adherence of commensal bacteria to mucus but structural information is scarce. Here we report the first molecular and structural characterization of a novel cell-surface protein, Lar_0958 from Lactobacillus reuteri JCM 1112(T) , mediating adhesion of L. reuteri human strains to mucus. Lar_0958 is a modular protein of 133 kDa containing six repeat domains, an N-terminal signal sequence and a C-terminal anchoring motif (LPXTG). Lar_0958 homologues are expressed on the cell-surface of L. reuteri human strains, as shown by flow-cytometry and immunogold microscopy. Adhesion of human L. reuteri strains to mucus in vitro was significantly reduced in the presence of an anti-Lar_0958 antibody and Lar_0958 contribution to adhesion was further confirmed using a L. reuteri ATCC PTA 6475 lar_0958 KO mutant (6475-KO). The X-ray crystal structure of a single Lar_0958 repeat, determined at 1.5 Å resolution, revealed a divergent immunoglobulin (Ig)-like β-sandwich fold, sharing structural homology with the Ig-like inter-repeat domain of internalins of the food borne pathogen Listeria monocytogenes. These findings provide unique structural insights into cell-surface protein repeats involved in adhesion of Gram-positive bacteria to the intestine. © 2014 John Wiley & Sons Ltd.

  7. Filamentous hemagglutinin of Bordetella pertussis: a key adhesin with immunomodulatory properties?

    Czech Academy of Sciences Publication Activity Database

    Romero, Rodrigo, Villarino; Osička, Radim; Šebo, Peter

    2014-01-01

    Roč. 9, č. 12 (2014), s. 1339-1360 ISSN 1746-0913 R&D Projects: GA ČR(CZ) P302/11/0580; GA ČR(CZ) GA13-14547S Institutional support: RVO:61388971 Keywords : Bordetella * adhesion * integrins * filamentous hemagglutinin Subject RIV: EE - Microbiology, Virology Impact factor: 4.275, year: 2014

  8. Association of number of tandem repeats in two important adhesins in Mycoplasma hyopneumoniae

    Directory of Open Access Journals (Sweden)

    L. F. dos Santos

    2015-10-01

    Full Text Available RESUMODiversidade genética de Mycoplasma hyopneumoniae tem sido relatada em análise múltipla de repetições em tandem em número variável (MLVA. O objetivo deste estudo foi descrever a distribuição espacial e a heterogeneidade genética de tipos de M. hyopneumoniae no Brasil, bem como investigar a correlação entre regiões de repetição 1 (RR1 e 3 (RR3 de duas adesinas importantes (P97 e P146. Foram identificados 39 tipos de MLVA baseados no número de repetições em tandem em P97 RR1 e RR3 P146. A correlação negativa significativa (Spearman's rho = -0,26; P = 0,022 entre P97 RR1 e RR3 P146 foi observada, o que sugere um possível mecanismo compensatório que permitiria a bactéria manter a sua capacidade de adesão. Os resultados contribuem para compreender a epidemiologia das M. hyopneumoniae no quarto maior país produtor de suínos do mundo.

  9. Computational Protein Design

    DEFF Research Database (Denmark)

    Johansson, Kristoffer Enøe

    Proteins are the major functional group of molecules in biology. The impact of protein science on medicine and chemical productions is rapidly increasing. However, the greatest potential remains to be realized. The fi eld of protein design has advanced computational modeling from a tool of support...... to a central method that enables new developments. For example, novel enzymes with functions not found in natural proteins have been de novo designed to give enough activity for experimental optimization. This thesis presents the current state-of-the-art within computational design methods together...... with a novel method based on probability theory. With the aim of assembling a complete pipeline for protein design, this work touches upon several aspects of protein design. The presented work is the computational half of a design project where the other half is dedicated to the experimental part...

  10. The Design Space

    DEFF Research Database (Denmark)

    Heape, Chris

    was to also understand what was meaningful to the students in their process of designing, a hermeneutic phenomenological research perspective was also adopted throughout this study, where human actions and language are considered as expressions of meaning in the context within which they occur. From......, the one effecting the other. As much as the processes of construction, exploration and expansion of a Design Space can be described in general terms as social and as design activities, it also emerged that there are a number of interrelated processes, sensibilities and skills in constant transaction...... the shifting flow of adjustments and perspectives necessary to relate to the ongoing contingency of a design task. From these interweavings a design proposal is gradually pulled to the fore as an emergent composition, a figure of parts that is directly related to the structure and ground of a Design Space...

  11. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  12. IMPROVING CONCEPTUAL DESIGN QUALITY

    DEFF Research Database (Denmark)

    Bush, Stuart; Robotham, Antony John

    1999-01-01

    designer to identify clear targets for design improvement and to measure the effectiveness of any new solution, whilst attention to QFD ensures customer requirements are still being satisfied.Often, SME's are not aware of many of the best design practices and so are not able to meet the demand......This paper will consider how Quality Function Deployment (QFD) and Design for Manufacture and Assembly (DFMA) processes can be used to improve the design quality of products at the concept stage. We appreciate that both QFD and DFMA are techniques that have been used for some time by mature product...... quality is maintained in design project work. The projects described have been carried out with products manufactured by small to medium sized enterprises (SME's), where we have found significant opportunities for product improvement. The quantitative nature of DFMA analysis results allows the novice...

  13. Performance Aided Design

    DEFF Research Database (Denmark)

    Parigi, Dario

    2014-01-01

    paradigm where the increasing integration of parametric tools and performative analysis is changing the way we learn and design. The term Performance Aided Architectural Design (PAD) is proposed at the Master of Science of Architecture and Design at Aalborg University, with the aim of extending a tectonic...... tradition of architecture with computational tools, preparing the basis for the creation of the figure of a modern master builder, sitting at the boundary of the disciplines of architecture and engineering. Performance Aided Design focuses on the role of performative analysis, embedded tectonics......, and computational methods tools to trigger creativity and innovative understanding of relation between form material and a increasingly wide range of performances in architectural design. The ultimate goal is to pursue a design approach that aims at embracing rather than excluding the complexity implicit...

  14. Ethics and technology design

    DEFF Research Database (Denmark)

    Albrechtslund, Anders

    This article offers a discussion of the connection between technology and values and, specifically, I take a closer look at ethically sound design. In order to bring the discussion into a concrete context, the theory of Value Sensitive Design (VSD) will be the focus point. To illustrate my argument...... concerning design ethics, the discussion involves a case study of an augmented window, designed by the VSD Research Lab, which has turned out to be a potentially surveillanceenabling technology. I call attention to a “positivist problem” that has to do with the connection between the design context......, a design theory must accept that foresight is limited to anticipation rather than prediction. To overcome the positivist problem, I suggest a phenomenological approach to technology inspired by Don Ihde’s concept of multistability. This argument, which is general in nature and thus applies to any theory...

  15. Teaching sustainable design

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, P.; Haggard, K.; Knuckles, A.; Le Noble, J. [California Polytechnic State Univ., San Luis Obispo, CA (United States)

    1995-11-01

    Sustainable design is inclusive, holistic and integrative. It require humility and guts, caring and a certain degree of stubbornness. It helps to do it cooperatively in a group. Human interest in sustainability has gained a great deal of impetus over the last several years as the problems of the late 20th and the early 21st century have become clearer. Design for sustainability broadens and integrates many previously separate design concerns to create a unified approach that is both compelling and ripe with new possibilities. Ecosystem regeneration, ecological land use planning, biometric design, regional environmental and economic viability, natural landscape maintenance, resource optimization, integrated infrastructure system, neotraditional and pedestrian oriented urban design, passive solar architecture, appropriate technology, renewable building materials, healthy buildings, and the aesthetics of place; are a few of these design concerns that, when welded together, can create sustainability.

  16. Human Systems Design Criteria

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1982-01-01

    This paper deals with the problem of designing more humanised computer systems. This problem can be formally described as the need for defining human design criteria, which — if used in the design process - will secure that the systems designed get the relevant qualities. That is not only...... the necessary functional qualities but also the needed human qualities. The author's main argument is, that the design process should be a dialectical synthesis of the two points of view: Man as a System Component, and System as Man's Environment. Based on a man's presentation of the state of the art a set...... of design criteria is suggested and their relevance discussed. The point is to focus on the operator rather than on the computer. The crucial question is not to program the computer to work on its own conditions, but to “program” the operator to function on human conditions....

  17. The Strategic Design Perspective

    DEFF Research Database (Denmark)

    Rasmussen, Jørgen

    2006-01-01

    In this article I argue, and exemplify, that designers working in close relation with industry, can have significant influence on the nature and the quality of the products (or services) produced by the companies. In order to achieve this, the designer must become one of the decisive factors...... in the strategic framework of the company. This is done by taking the design process to the business floor of the company and using the design competence to innovate, not only products, but the fundamental concepts for product selection. Using design as a strategic tool will cause entirely new products to emerge...... and will make entire groups of products change into services. In this way new markets will appear to benefit the innovative companies, and if designers do their job well, the focus will be on the users, and thereby benefiting them as well. An example of this process is Novo Nordisk. This pharmaceutical company...

  18. Liaison based assembly design

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.; Kholwadwala, D.; Wilson, R.H.

    1996-12-01

    Liaison Based Assembly Design extends the current information infrastructure to support design in terms of kinematic relationships between parts, or liaisons. These liaisons capture information regarding contact, degrees-of-freedom constraints and containment relationships between parts in an assembly. The project involved defining a useful collection of liaison representations, investigating their properties, and providing for maximum use of the data in downstream applications. We tested our ideas by implementing a prototype system involving extensions to Pro/Engineer and the Archimedes assembly planner. With an expanded product model, the design system is more able to capture design intent. When a product update is attempted, increased knowledge availability improves our ability to understand the effect of design changes. Manufacturing and analysis disciplines benefit from having liaison information available, so less time is wasted arguing over incomplete design specifications and our enterprise can be more completely integrated.

  19. Posthumanism and Design

    Directory of Open Access Journals (Sweden)

    Laura Forlano

    Full Text Available Since at least the mid-1980s, design has been dominated by a human-centered and user-centered paradigm. Currently, the implications of technological and environmental transformations are challenging designers to focus on complex socio-technical systems. This article traces emergent discussions around posthumanism from across a range of disciplines and perspectives, and considers examples from emerging design practices that emphasize the interrelations between human and nonhuman actors. Specifically, this article reviews literature from actor-network theory (ANT, feminist new materialism, object-oriented ontology, non-representational theory, and transhumanism to inform the development of new methodologies and practices in the field of design. Finally, this article presents critiques of posthumanism from critical race theory and decolonial theory to consider how emergent design perspectives might better support values such as equality and justice for humans and nonhumans that have been traditionally ignored in design processes.

  20. Assembly tool design

    International Nuclear Information System (INIS)

    Kanamori, Naokazu; Nakahira, Masataka; Ohkawa, Yoshinao; Tada, Eisuke; Seki, Masahiro

    1996-06-01

    The reactor core of the International Thermonuclear Experimental Reactor (ITER) is assembled with a number of large and asymmetric components within a tight tolerance in order to assure the structural integrity for various loads and to provide the tritium confinement. In addition, the assembly procedure should be compatible with remote operation since the core structures will be activated by 14-MeV neutrons once it starts operation and thus personal access will be prohibited. Accordingly, the assembly procedure and tool design are quite essential and should be designed from the beginning to facilitate remote operation. According to the ITER Design Task Agreement, the Japan Atomic Energy Research Institute (JAERI) has performed design study to develop the assembly procedures and associated tool design for the ITER tokamak assembly. This report describes outlines of the assembly tools and the remaining issues obtained in this design study. (author)

  1. Automation of substation design

    Energy Technology Data Exchange (ETDEWEB)

    Milks, D. [Autodesk Inc., San Rafael, CA (United States); Scullion, T. [AutomationForce, Burlington, ON (Canada)

    2010-07-01

    Smart libraries and substation design tools are now being used by electric utilities to simplify and optimize the design of electrical control systems. A rules-based design and database approach was used to determine the placement of connections and for designing schematics, panel layouts wiring diagrams and cable schedules. Substation design solutions can reduce labour resources and field errors. Methods of synthesizing technologies in a database-centric architecture were discussed along with methods of selecting and adopting appropriate design technologies and methods for gaining efficiencies and managing change within organizations. The study demonstrated that the successful adoption of new technology requires a clear understanding of business objectives, technology requirements, and management support. 2 refs., 5 figs.

  2. Design of mechanical joints

    CERN Document Server

    Blake, Alexander

    2018-01-01

    A cornerstone publication that covers the basic principles and practical considerations of design methodology for joints held by rivets, bolts, weld seams, and adhesive materials, Design of Mechanical Joints gives engineers the practical results and formulas they need for the preliminary design of mechanical joints, combining the essential topics of joint mechanics...strength of materials...and fracture control to provide a complete treatment of problems pertinent to the field of mechanical connections.

  3. Creating flat design websites

    CERN Document Server

    Pratas, Antonio

    2014-01-01

    This book contains practical, step-by-step tutorials along with plenty of explanation about designing your flat website. Each section is introduced sequentially, building up your web design skills and completing your website.Creating Flat Design Websites is ideal for you if you are starting on your web development journey, but this book will also benefit seasoned developers wanting to start developing in flat.

  4. Logical database design principles

    CERN Document Server

    Garmany, John; Clark, Terry

    2005-01-01

    INTRODUCTION TO LOGICAL DATABASE DESIGNUnderstanding a Database Database Architectures Relational Databases Creating the Database System Development Life Cycle (SDLC)Systems Planning: Assessment and Feasibility System Analysis: RequirementsSystem Analysis: Requirements Checklist Models Tracking and Schedules Design Modeling Functional Decomposition DiagramData Flow Diagrams Data Dictionary Logical Structures and Decision Trees System Design: LogicalSYSTEM DESIGN AND IMPLEMENTATION The ER ApproachEntities and Entity Types Attribute Domains AttributesSet-Valued AttributesWeak Entities Constraint

  5. Learning Python design patterns

    CERN Document Server

    Zlobin, Gennadiy

    2013-01-01

    This book takes a tutorial-based and user-friendly approach to covering Python design patterns. Its concise presentation means that in a short space of time, you will get a good introduction to various design patterns.If you are an intermediate level Python user, this book is for you. Prior knowledge of Python programming is essential. Some knowledge of UML is also required to understand the UML diagrams which are used to describe some design patterns.

  6. Designing for Interactional Empowerment

    OpenAIRE

    Ståhl, Anna

    2014-01-01

    This thesis further defines how to reach Interactional Empowerment through design for users. Interactional Empowerment is an interaction design program within the general area of affective interaction, focusing on the users’ abil­ity to reflect, express themselves and engage in profound meaning-making. This has been explored through design of three systems eMoto, Affective Di­ary and Affective Health, which all mirror users’ emotions or bodily reactions in interaction in some way. From these ...

  7. The Seismographic Design Concept

    DEFF Research Database (Denmark)

    Salamon, Karen Lisa; Engholm, Ida

    2015-01-01

    This article gives an overview of the theoretical development of the design concept through two centuries in Europe and North America. Drawing on the academic disciplines of design history and anthropology, the authors present seminal moments in the theorization of “design”. Historically formativ...... argues for a more historically reflective glance on theory’s influence on the moulding of practice from ideology also in the context of design, and presents itself as a step in this self reflective direction....

  8. Rectenna system design

    Science.gov (United States)

    Brown, W. C.; Dickinson, R. M.; Nalos, E. J.; Ott, J. H.

    1980-01-01

    The function of the rectenna in the solar power satellite system is described and the basic design choices based on the desired microwave field concentration and ground clearance requirements are given. One important area of concern, from the EMI point of view, harmonic reradiation and scattering from the rectenna is also designed. An optimization of a rectenna system design to minimize costs was performed. The rectenna cost breakdown for a 56 w installation is given as an example.

  9. The Designer as Facilitator

    DEFF Research Database (Denmark)

    Bang, Anne Louise

    2009-01-01

    a very strong relation to design practice. Focusing on so-called emotional values the project investigates how stakeholders and end-users can actively contribute to the design process. Even though that the collaborating company has an in-house design unit responsible for certain emotional as well...... as functional aspects in the development process it is a highly technical and functional trade. It is therefore assumed that there is a ‘sleeping' potential which can be released investigating emotional values....

  10. INTUITION IN INTERIOR DESIGN

    Directory of Open Access Journals (Sweden)

    Irina Solovyova

    2008-11-01

    Full Text Available Intuition enables individuals to develop an understanding of the structure of complex systems. In interior design many decisions are reached intuitively even though the process of formulating solutions may be argued rationally. Intuition is intrinsically intertwined with our collateral experiences, memories, and implicit thought. Design intuition draws on our entire experience, not only on what we consciously isolate as relevant information. In education we prohibit students from relying on their intuition and require solutions based on pure reason. The author of this paper argues for bringing intuitive decision making back into interior design as a legitimate design tactic.

  11. Head First Web Design

    CERN Document Server

    Watrall, Ethan

    2008-01-01

    Want to know how to make your pages look beautiful, communicate your message effectively, guide visitors through your website with ease, and get everything approved by the accessibility and usability police at the same time? Head First Web Design is your ticket to mastering all of these complex topics, and understanding what's really going on in the world of web design. Whether you're building a personal blog or a corporate website, there's a lot more to web design than div's and CSS selectors, but what do you really need to know? With this book, you'll learn the secrets of designing effecti

  12. HVAC systems design handbook

    CERN Document Server

    Haines, Roger W

    2010-01-01

    Thoroughly updated with the latest codes, technologies, and practices, this all-in-one resource provides details, calculations, and specifications for designing efficient and effective residential, commercial, and industrial HVAC systems. HVAC Systems Design Handbook, Fifth Edition, features new information on energy conservation and computer usage for design and control, as well as the most recent International Code Council (ICC) Mechanical Code requirements. Detailed illustrations, tables, and essential HVAC equations are also included. This comprehensive guide contains everything you need to design, operate, and maintain peak-performing HVAC systems.

  13. Design as Montage

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Kjærsgaard, Mette

    The paper explores the role of video and (visual) anthropology in design and product development processes from creating insights about users to developing design ideas in interdisciplinary teams. In the paper we suggest montage as a metaphor for understanding how meaning and ideas are created...... in design processes. Rather than viewing montage as a particular style of filmmaking, we see the design process itself as a montage, a process where different heterogeneous materials – sketches, video, prototypes, etc. – as well as different professional and disciplinary perspectives are brought together...

  14. Design of the EFR

    International Nuclear Information System (INIS)

    Mitchell, C.H.; Debru, M.

    1992-01-01

    The design work on the European Fast Reactor (EFR) started in the spring of 1988 at the request of the EFR Utilities Group (EFRUG), which comprises electricity producing utilities from France, Germany, Great Britain, and Italy. Other European utilities have expressed their interest in joining the EFR project. The EFR design work is being performed by EFR Associates, a group of design and construction companies that includes: (1) Novatome, a division of Framatome, France; (2) NNC, a member of the GEC group of companies, Great Britain; and (3) Siemens Engineerzeugung KWU, Germany. A first consistent design of a nuclear island for the EFR as submitted to EFRUG in the spring of 1990. This design combines the best features from previous national designs (SPX2, SNR2, and CDFR). Since 1990, the design validation work has been in an advanced stage, and EFR Associates proposal for the main features of a consistent design, which was presented to EFRUG in autumn 1991 (mid-phase 2), represented an important milestone in the design phase of the project

  15. Communicating (by) Design 2009

    DEFF Research Database (Denmark)

    Elkær, Tim Nøhr

    The paper discusses the current change of role and status of the representation as a means to communicate design in the digital era. It outlines two opposite directions for the development of software-technology, and brings forward current research, on the didactic aspects of introducing digital...... software into the curriculum of architechture and design education. The paper describes a workshop held at the Danish Design School, where students proficient in using digital media, are challenged to use analogue models instead, to rediscover and utilize some of the creative potentials offered......; Ambiguity; Heuristics; Design education...

  16. VT Designated Downtown Boundary

    Data.gov (United States)

    Vermont Center for Geographic Information — Downtown designation provides communities with financial incentives, training and technical assistance to support local efforts to restore historic buildings,...

  17. Designing for Immediate Play

    DEFF Research Database (Denmark)

    Pichlmair, Martin; Mech, Lena; Sicart, Miguel Angel

    2017-01-01

    This paper is concerned with designing for immediate play, the experience that a player has when joining a game designed for being played without particular preparation. Museum games, urban games, casual sports, and ad-hoc multiplayer video games are kinds of games that facilitate immediate play...... offer using examples and expert opinions. While most practices and game examples mentioned in this paper are from non-digital games, a special focus is put on the role of technology in immediately playable experiences. Still, the examined design dimensions are independent of the technological foundation...... of the game. This paper provides a starting point for designing better immediate play situations....

  18. EMI filter design

    CERN Document Server

    Ozenbaugh, Richard Lee

    2011-01-01

    With today's electrical and electronics systems requiring increased levels of performance and reliability, the design of robust EMI filters plays a critical role in EMC compliance. Using a mix of practical methods and theoretical analysis, EMI Filter Design, Third Edition presents both a hands-on and academic approach to the design of EMI filters and the selection of components values. The design approaches covered include matrix methods using table data and the use of Fourier analysis, Laplace transforms, and transfer function realization of LC structures. This edition has been fully revised

  19. Clockwork game design

    CERN Document Server

    Burgun, Keith

    2015-01-01

    Only by finding and focusing on a core mechanism can you further your pursuit of elegance in strategy game design.Clockwork Game Design is the most functional and directly applicable theory for game design. It details the clockwork game design pattern, which focuses on building around fundamental functionality. You can then use this understanding to prescribe a system for building and refining your rulesets. A game can achieve clarity of purpose by starting with a strong core, then removing elements that conflict with that core while adding elements that support it.Filled with examples and exe

  20. Industrial Design: Tableware

    OpenAIRE

    Sullivan, Martha Lynn Luttrell

    2006-01-01

    The goal of my graduate thesis is to design a dinner service set suitable for mass manufacture. The purpose of completing an academic study of dinnerware as an industrial designer is to gain a mastery of a product used everyday in and out of the home. With such a rich history in ceramics, it is challenging to design a new dinner service set that is functional, enhances the aesthetics of a meal and sustains the intimate relationship of everyday use by adapting to lives. My particular design id...

  1. Design (research) practice

    DEFF Research Database (Denmark)

    Binder, Thomas; Brandt, Eva

    2017-01-01

    possibilities through experimentation (Brandt and Binder 2007). Likewise in relation to design research we have argued that “the possible is always contingent and though research may convincingly provide arguments for certain possibilities both search and arguments have to be guided by programs that set...... substantiate or challenge this view and the dialectic between program and probing is in our view central to any design practice” (Binder and Redström 2006: 4). Our suggestion is to see design research practices as fundamentally homologous to any other design practices both in terms of the way they are driven...

  2. Programmable Array Logic Design

    International Nuclear Information System (INIS)

    Demon Handoyo; Djen Djen Djainal

    2007-01-01

    Good digital circuit design that part of a complex system, often becoming a separate problem. To produce finishing design according to wanted performance is often given on to considerations which each other confuse, hence thereby analyse optimization become important in this case. To realization is made design logic program, the first are determined global diagram block, then are decided contents of these block diagram, and then determined its interconnection in the form of logic expression, continued with election of component. These steps are done to be obtained the design with low price, easy in its interconnection, minimal volume, low power and certainty god work. (author)

  3. Pipe drafting and design

    CERN Document Server

    Parisher, Roy A; Parisher

    2000-01-01

    Pipe designers and drafters provide thousands of piping drawings used in the layout of industrial and other facilities. The layouts must comply with safety codes, government standards, client specifications, budget, and start-up date. Pipe Drafting and Design, Second Edition provides step-by-step instructions to walk pipe designers and drafters and students in Engineering Design Graphics and Engineering Technology through the creation of piping arrangement and isometric drawings using symbols for fittings, flanges, valves, and mechanical equipment. The book is appropriate primarily for pipe

  4. Reusing Design Knowledge Based on Design Cases and Knowledge Map

    Science.gov (United States)

    Yang, Cheng; Liu, Zheng; Wang, Haobai; Shen, Jiaoqi

    2013-01-01

    Design knowledge was reused for innovative design work to support designers with product design knowledge and help designers who lack rich experiences to improve their design capacity and efficiency. First, based on the ontological model of product design knowledge constructed by taxonomy, implicit and explicit knowledge was extracted from some…

  5. Process design (exterior – interior design)

    OpenAIRE

    Sandeva, Vaska; Despot, Katerina

    2013-01-01

    The design is a complex process of spatial organization and creative problem object. It switched to the study of complex natural conditions (analysis and evaluation) and the development of compositional solution structure of the object. Construction and shaping of all buildings whether it is exterior or interior, be it street, Square apartment building, park or greater forest massif, public facility (administrative buildings, hospitals, schools, galleries etc.), residential object (garsion...

  6. Ship design methodologies of preliminary design

    CERN Document Server

    Papanikolaou, Apostolos

    2014-01-01

    This book deals with ship design and in particular with methodologies of the preliminary design of ships. The book is complemented by a basic bibliography and five appendices with useful updated charts for the selection of the main dimensions and other basic characteristics of different types of ships (Appendix A), the determination of hull form  from the data of systematic hull form series (Appendix B), the detailed description of the relational method for the preliminary estimation of ship weights (Appendix C), a brief review of the historical evolution of shipbuilding science and technology from the prehistoric era to date (Appendix D) and finally a historical review of regulatory developments of ship's damage stability to date (Appendix E).  The book can be used as textbook for ship design courses or as additional reading for university or college students of naval architecture courses and related disciplines; it may also serve as a reference book for naval architects, practicing engineers of rel...

  7. The design of the MAD Design Program

    International Nuclear Information System (INIS)

    Niederer, J.

    1992-01-01

    The study of long term stability in particle accelerators has long been served by a group of widely circulated computer programs. The progress in these programs has mirrored the growth and versatility in accelerator size, complexity, and purpose, as well as evolving technologies in computing software and hardware. A number of large accelerator projects during the last decade were designed with the aid of physics programs either written for, or tailored for the project at hand, each invariably benefiting from contributions of previous workers. This paper outlines the recent history of of expample of an accelerator lattice model tool kit, the Methodical Accelerator Design (MAD) Program, which has tried to knit together this collective wisdom of the accelerator community, The ideas behind the software design of the program itself are traced here; the accelerator physics contents and origins are thoroughly documented elsewhere. These informal notes have a Brookhaven flavor, in part because of early BNL efforts to generalize the ways that technical problems are organized and presented to computers. Some recent BNL applications not covered in the extensive CERN documentation are also included

  8. Problem and design drawing for solution of precision design drawing and machine design

    International Nuclear Information System (INIS)

    Heo, Gil

    1982-04-01

    The contents of this book are basic of design drawing, problem of machine design, problem of precision design drawing, problem of planar figure of sheet metal, design drawing for solution of machine design, design drawing for solution of precision design drawing and design drawing for planar figure of sheet metal. It tells of the problems and gives the solutions on precision design drawing and machine design.

  9. Typography of web design

    OpenAIRE

    Uhlířová, Martina

    2016-01-01

    Typography is one of the most important elements of web design and marketing. Good typography makes web design more appealing, which is important for readers in evaluating titles and the quality of text. The aim of this thesis is to provide a characterization of good and bad typography. I will use this characterization to identify modern typographical trends in a digital background....

  10. Subgrade design models

    CSIR Research Space (South Africa)

    Theyse, HL

    2002-02-01

    Full Text Available procedure commonly used in South Africa, namely the South African Mechanistic-Empirical Design Method (SAMDM). This was achieved through the development of a new design approach and permanent deformation model for the pavement subgrade. The new distress...

  11. Textiles and Apparel Design.

    Science.gov (United States)

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This document contains teacher's materials for a seven-unit secondary education vocational home economics course on textiles and apparel design. The units cover: (1) fiber/fiber characteristics and textile development (including fabrication and dyeing, printing, and finishing); (2) textile and apparel design industries (including their history and…

  12. Optimal Market Design

    NARCIS (Netherlands)

    Boone, J.; Goeree, J.K.

    2010-01-01

    This paper introduces three methodological advances to study the optimal design of static and dynamic markets. First, we apply a mechanism design approach to characterize all incentive-compatible market equilibria. Second, we conduct a normative analysis, i.e. we evaluate alternative competition and

  13. Designing and testing prototypes

    NARCIS (Netherlands)

    Vereijken, P.; Wijnands, F.; Stol, W.

    1995-01-01

    This second progress report focuses on designing a theoretical prototype by linking parameters to methods and designing the methods in this context until they are ready for initial testing. The report focuses also on testing and improving the prototype in general and the methods in particular until

  14. Cavity design programs

    International Nuclear Information System (INIS)

    Nelson, E.M.

    1996-01-01

    Numerous computer programs are available to help accelerator physicists and engineers model and design accelerator cavities and other microwave components. This article discusses the problems these programs solve and the principles upon which these programs are based. Some examples of how these programs are used in the design of accelerator cavities are also given

  15. Architectural design decisions

    NARCIS (Netherlands)

    Jansen, Antonius Gradus Johannes

    2008-01-01

    A software architecture can be considered as the collection of key decisions concerning the design of the software of a system. Knowledge about this design, i.e. architectural knowledge, is key for understanding a software architecture and thus the software itself. Architectural knowledge is mostly

  16. Design for volume reduction

    NARCIS (Netherlands)

    Wever, R.; Boks, C.; Stevels, A.

    2007-01-01

    Traditionally packaging design-for-sustainability (DfS) strongly focuses on resource conservation and material recycling. The type and amount of materials used has been the driver in design. For consumer electronics (CE) products this weight-based approach is too limited; a volume-based approach is

  17. Design of timber groynes

    NARCIS (Netherlands)

    Perdok, U.; Crossman, M.; Verhagen, H.J.; Howard, S.; Simm, J.

    2003-01-01

    The performance and durability of timber groynes (or 'groins') is highly dependent on the design and detailing of the structure. Using knowledge and experience developed over generations an effective functional design can be achieved, which may ultimately result in lower whole life costs and provide

  18. Intelligent design som videnskab?

    DEFF Research Database (Denmark)

    Klausen, Søren Harnow

    2007-01-01

    Diskuterer hvorvidt intelligent design kan betegnes som videnskab; argumenterer for at dette grundet fraværet af klare demarkationskriterier næppe kan afvises.......Diskuterer hvorvidt intelligent design kan betegnes som videnskab; argumenterer for at dette grundet fraværet af klare demarkationskriterier næppe kan afvises....

  19. Implementing Target Value Design.

    Science.gov (United States)

    Alves, Thais da C L; Lichtig, Will; Rybkowski, Zofia K

    2017-04-01

    An alternative to the traditional way of designing projects is the process of target value design (TVD), which takes different departure points to start the design process. The TVD process starts with the client defining an allowable cost that needs to be met by the design and construction teams. An expected cost in the TVD process is defined through multiple interactions between multiple stakeholders who define wishes and others who define ways of achieving these wishes. Finally, a target cost is defined based on the expected profit the design and construction teams are expecting to make. TVD follows a series of continuous improvement efforts aimed at reaching the desired goals for the project and its associated target value cost. The process takes advantage of rapid cycles of suggestions, analyses, and implementation that starts with the definition of value for the client. In the traditional design process, the goal is to identify user preferences and find solutions that meet the needs of the client's expressed preferences. In the lean design process, the goal is to educate users about their values and advocate for a better facility over the long run; this way owners can help contractors and designers to identify better solutions. This article aims to inform the healthcare community about tools and techniques commonly used during the TVD process and how they can be used to educate and support project participants in developing better solutions to meet their needs now as well as in the future.

  20. Designing well with others

    DEFF Research Database (Denmark)

    Henriksen, Thomas Duus

    2013-01-01

    Abstract: Have you ever been sitting in a game-design workshop trying to make a game work when suddenly someone suggested incorporating elements like drawing a card or rolling a die as a contribution to creating a functional design? How did that make you feel? Yes, so did I, but please read a bit...