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Sample records for unknown bacterial modification

  1. Characterization of unknown genetic modifications using high throughput sequencing and computational subtraction

    Butenko Melinka A

    2009-10-01

    Full Text Available Abstract Background When generating a genetically modified organism (GMO, the primary goal is to give a target organism one or several novel traits by using biotechnology techniques. A GMO will differ from its parental strain in that its pool of transcripts will be altered. Currently, there are no methods that are reliably able to determine if an organism has been genetically altered if the nature of the modification is unknown. Results We show that the concept of computational subtraction can be used to identify transgenic cDNA sequences from genetically modified plants. Our datasets include 454-type sequences from a transgenic line of Arabidopsis thaliana and published EST datasets from commercially relevant species (rice and papaya. Conclusion We believe that computational subtraction represents a powerful new strategy for determining if an organism has been genetically modified as well as to define the nature of the modification. Fewer assumptions have to be made compared to methods currently in use and this is an advantage particularly when working with unknown GMOs.

  2. Plasma surface modification of rigid contact lenses decreases bacterial adhesion.

    Wang, Yingming; Qian, Xuefeng; Zhang, Xiaofeng; Xia, Wei; Zhong, Lei; Sun, Zhengtai; Xia, Jing

    2013-11-01

    Contact lens safety is an important topic in clinical studies. Corneal infections usually occur because of the use of bacteria-carrying contact lenses. The current study investigated the impact of plasma surface modification on bacterial adherence to rigid contact lenses made of fluorosilicone acrylate materials. Boston XO and XO2 contact lenses were modified using plasma technology (XO-P and XO2-P groups). Untreated lenses were used as controls. Plasma-treated and control lenses were incubated in solutions containing Staphylococcus aureus or Pseudomonas aeruginosa. MTT colorimetry, colony-forming unit counting method, and scanning electron microscopy were used to measure bacterial adhesion. MTT colorimetry measurements showed that the optical density (OD) values of XO-P and XO2-P were significantly lower than those of XO and XO2, respectively, after incubation with S. aureus (P lenses and to the XO2-P versus XO2 lenses incubated with S. aureus (P lenses incubated with P. aeruginosa (P lenses. Plasma surface modification can significantly decrease bacterial adhesion to fluorosilicone acrylate contact lenses. This study provides important evidence of a unique benefit of plasma technology in contact lens surface modification.

  3. Assembly of Robust Bacterial Microcompartment Shells Using Building Blocks from an Organelle of Unknown Function

    Lassila, JK; Bernstein, SL; Kinney, JN; Axen, SD; Kerfeld, CA

    2014-05-29

    Bacterial microconnpartnnents (BMCs) sequester enzymes from the cytoplasmic environment by encapsulation inside a selectively permeable protein shell. Bioinformatic analyses indicate that many bacteria encode BMC clusters of unknown function and with diverse combinations of shell proteins. The genome of the halophilic myxobacterium Haliangium ochraceum encodes one of the most atypical sets of shell proteins in terms of composition and primary structure. We found that microconnpartnnent shells could be purified in high yield when all seven H. ochraceum BMC shell genes were expressed from a synthetic operon in Escherichia coll. These shells differ substantially from previously isolated shell systems in that they are considerably smaller and more homogeneous, with measured diameters of 39 2 nm. The size and nearly uniform geometry allowed the development of a structural model for the shells composed of 260 hexagonal units and 13 hexagons per icosahedral face. We found that new proteins could be recruited to the shells by fusion to a predicted targeting peptide sequence, setting the stage for the use of these remarkably homogeneous shells for applications such as three-dimensional scaffolding and the construction of synthetic BMCs. Our results demonstrate the value of selecting from the diversity of BMC shell building blocks found in genomic sequence data for the construction of novel compartments. (C) 2014 Elsevier Ltd. All rights reserved.

  4. InSourcerer: a high-throughput method to search for unknown metabolite modifications by mass spectrometry.

    Mrzic, Aida; Lermyte, Frederik; Vu, Trung Nghia; Valkenborg, Dirk; Laukens, Kris

    2017-09-15

    Using mass spectrometry, the analysis of known metabolite structures has become feasible in a systematic high-throughput fashion. Nevertheless, the identification of previously unknown structures remains challenging, partially because many unidentified variants originate from known molecules that underwent unexpected modifications. Here, we present a method for the discovery of unknown metabolite modifications and conjugate metabolite isoforms in a high-throughput fashion. The method is based on user-controlled in-source fragmentation which is used to induce loss of weakly bound modifications. This is followed by the comparison of product ions from in-source fragmentation and collision-induced dissociation (CID). Diagonal MS 2 -MS 3 matching allows the detection of unknown metabolite modifications, as well as substructure similarities. As the method relies heavily on the advantages of in-source fragmentation and its ability to 'magically' elucidate unknown modification, we have named it inSourcerer as a portmanteau of in-source and sorcerer. The method was evaluated using a set of 15 different cytokinin standards. Product ions from in-source fragmentation and CID were compared. Hierarchical clustering revealed that good matches are due to the presence of common substructures. Plant leaf extract, spiked with a mix of all 15 standards, was used to demonstrate the method's ability to detect these standards in a complex mixture, as well as confidently identify compounds already present in the plant material. Here we present a method that incorporates a classic liquid chromatography/mass spectrometry (LC/MS) workflow with fragmentation models and computational algorithms. The assumptions upon which the concept of the method was built were shown to be valid and the method showed that in-source fragmentation can be used to pinpoint structural similarities and indicate the occurrence of a modification. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Exploring the diversity of protein modifications: special bacterial phosphorylation systems

    Mijakovic, Ivan; Grangeasse, Christophe; Turgay, Kürşad

    2016-01-01

    Protein modifications not only affect protein homeostasis but can also establish new cellular protein functions and are important components of complex cellular signal sensing and transduction networks. Among these post-translational modifications, protein phosphorylation represents the one that ...

  6. Brood size modifications affect plumage bacterial assemblages of European starlings.

    Lucas, Françoise S; Moureau, Benoit; Jourdie, Violaine; Heeb, Philipp

    2005-02-01

    During reproduction, birds face trade-offs between time and energy devoted to parental effort and traits associated with self-maintenance. We manipulated brood sizes to investigate the effects of such trade-offs on feather bacterial densities and the structure of bacterial assemblages on feathers in adult European starlings, Sturnus vulgaris, and in vitro feather degradation. As predicted by a trade-off between parental effort and self-maintenance, we found that birds with enlarged broods had more free-living bacteria on their feathers than birds with reduced broods. Furthermore, we found a significant interaction between brood manipulation and original brood size on free-living bacterial densities suggesting that the trade-off is mediated by the adults' initial reproductive investment. In contrast, brood size manipulations had no significant effect on densities of attached bacteria. Using ribosomal intergenic spacer analysis (RISA), we demonstrated that brood manipulations significantly modified the structure (band pattern) of feather-degrading bacterial assemblages, but had no significant effect on their richness (number of bands) or the in vitro feather degradation. In vitro feather degradation varied in relation to the premanipulation brood size and positively with the richness of the feather degrading bacterial community. Besides brood manipulation effect, we found that ecological factors and individual traits, such as the age, the nest location or the capture date, shaped bacterial assemblages and feather degradation capacities.

  7. Modification of Bacterial Cellulose Biofilms with Xylan Polyelectrolytes.

    Santos, Sara M; Carbajo, José M; Gómez, Nuria; Ladero, Miguel; Villar, Juan C

    2017-11-28

    The effect of the addition of two [4-butyltrimethylammonium]-xylan chloride polyelectrolytes (BTMAXs) on bacterial cellulose (BC) was evaluated. The first strategy was to add the polyelectrolytes to the culture medium together with a cell suspension of the bacterium. After one week of cultivation, the films were collected and purified. The second approach consisted of obtaining a purified and homogenized BC, to which the polyelectrolytes were added subsequently. The films were characterized in terms of tear and burst indexes, optical properties, surface free energy, static contact angle, Gurley porosity, SEM, X-ray diffraction and AFM. Although there are small differences in mechanical and optical properties between the nanocomposites and control films, the films obtained by BC synthesis in the presence of BTMAXs were remarkably less opaque, rougher, and had a much lower specular gloss. The surface free energy depends on the BTMAXs addition method. The crystallinity of the composites is lower than that of the control material, with a higher reduction of this parameter in the composites obtained by adding the BTMAXs to the culture medium. In view of these results, it can be concluded that BC-BTMAX composites are a promising new material, for example, for paper restoration.

  8. Modification of Bacterial Cellulose Biofilms with Xylan Polyelectrolytes

    Sara M. Santos

    2017-11-01

    Full Text Available The effect of the addition of two [4-butyltrimethylammonium]-xylan chloride polyelectrolytes (BTMAXs on bacterial cellulose (BC was evaluated. The first strategy was to add the polyelectrolytes to the culture medium together with a cell suspension of the bacterium. After one week of cultivation, the films were collected and purified. The second approach consisted of obtaining a purified and homogenized BC, to which the polyelectrolytes were added subsequently. The films were characterized in terms of tear and burst indexes, optical properties, surface free energy, static contact angle, Gurley porosity, SEM, X-ray diffraction and AFM. Although there are small differences in mechanical and optical properties between the nanocomposites and control films, the films obtained by BC synthesis in the presence of BTMAXs were remarkably less opaque, rougher, and had a much lower specular gloss. The surface free energy depends on the BTMAXs addition method. The crystallinity of the composites is lower than that of the control material, with a higher reduction of this parameter in the composites obtained by adding the BTMAXs to the culture medium. In view of these results, it can be concluded that BC–BTMAX composites are a promising new material, for example, for paper restoration.

  9. A modification of the successive projections algorithm for spectral variable selection in the presence of unknown interferents.

    Soares, Sófacles Figueredo Carreiro; Galvão, Roberto Kawakami Harrop; Araújo, Mário César Ugulino; da Silva, Edvan Cirino; Pereira, Claudete Fernandes; de Andrade, Stéfani Iury Evangelista; Leite, Flaviano Carvalho

    2011-03-09

    This work proposes a modification to the successive projections algorithm (SPA) aimed at selecting spectral variables for multiple linear regression (MLR) in the presence of unknown interferents not included in the calibration data set. The modified algorithm favours the selection of variables in which the effect of the interferent is less pronounced. The proposed procedure can be regarded as an adaptive modelling technique, because the spectral features of the samples to be analyzed are considered in the variable selection process. The advantages of this new approach are demonstrated in two analytical problems, namely (1) ultraviolet-visible spectrometric determination of tartrazine, allure red and sunset yellow in aqueous solutions under the interference of erythrosine, and (2) near-infrared spectrometric determination of ethanol in gasoline under the interference of toluene. In these case studies, the performance of conventional MLR-SPA models is substantially degraded by the presence of the interferent. This problem is circumvented by applying the proposed Adaptive MLR-SPA approach, which results in prediction errors smaller than those obtained by three other multivariate calibration techniques, namely stepwise regression, full-spectrum partial-least-squares (PLS) and PLS with variables selected by a genetic algorithm. An inspection of the variable selection results reveals that the Adaptive approach successfully avoids spectral regions in which the interference is more intense. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Structural modifications of bacterial lipopolysaccharide that facilitate Gram-negative bacteria evasion of host innate immunity

    Motohiro eMatsuura

    2013-05-01

    Full Text Available Bacterial lipopolysaccharide (LPS, a cell wall component characteristic of Gram-negative bacteria, is a representative pathogen-associated molecular pattern that allows mammalian cells to recognize bacterial invasion and trigger innate immune responses. The polysaccharide moiety of LPS primary plays protective roles for bacteria such as prevention from complement attacks or camouflage with common host carbohydrate residues. The lipid moiety, termed lipid A, is recognized by the Toll-like receptor 4 (TLR4/MD-2 complex, which transduces signals for activation of host innate immunity. The basic structure of lipid A is a glucosamine disaccharide substituted by phosphate groups and acyl groups. Lipid A with 6 acyl groups (hexa-acylated form has been indicated to be a strong stimulator of the TLR4/MD-2 complex. This type of lipid A is conserved among a wide variety of Gram-negative bacteria, and those bacteria are easily recognized by host cells for activation of defensive innate immune responses. Modifications of the lipid A structure to less-acylated forms have been observed in some bacterial species, and those forms are poor stimulators of the TLR4/MD-2 complex. Such modifications are thought to facilitate bacterial evasion of host innate immunity, thereby enhancing pathogenicity. This hypothesis is supported by studies of Yersinia pestis LPS, which contains hexa-acylated lipid A when the bacterium grows at 27ºC (the temperature of the vector flea, and shifts to contain less-acylated forms when grown at the human body temperature of 37ºC. This alteration of lipid A forms following transmission of Y. pestis from fleas to humans contributes predominantly to the virulence of this bacterium over other virulence factors. A similar role for less-acylated lipid A forms has been indicated in some other bacterial species, such as Francisella tularensis, Helicobacter pylori, and Porphyromonas gingivalis, and further studies to explore this concept are

  11. In situ and ex situ modifications of bacterial cellulose for applications in tissue engineering.

    Stumpf, Taisa Regina; Yang, Xiuying; Zhang, Jingchang; Cao, Xudong

    2018-01-01

    Bacterial cellulose (BC) is secreted by a few strains of bacteria and consists of a cellulose nanofiber network with unique characteristics. Because of its excellent mechanical properties, outstanding biocompatibilities, and abilities to form porous structures, BC has been studied for a variety of applications in different fields, including the use as a biomaterial for scaffolds in tissue engineering. To extend its applications in tissue engineering, native BC is normally modified to enhance its properties. Generally, BC modifications can be made by either in situ modification during cell culture or ex situ modification of existing BC microfibers. In this review we will first provide a brief introduction of BC and its attributes; this will set the stage for in-depth and up-to-date discussions on modified BC. Finally, the review will focus on in situ and ex situ modifications of BC and its applications in tissue engineering, particularly in bone regeneration and wound dressing. Copyright © 2016. Published by Elsevier B.V.

  12. The relationship between sea ice bacterial community structure and biogeochemistry: A synthesis of current knowledge and known unknowns

    Jeff S. Bowman

    2015-10-01

    Full Text Available Abstract Sea ice plays an important role in high latitude biogeochemical cycles, ecosystems, and climate. A complete understanding of how sea ice biogeochemistry contributes to these processes must take into account the metabolic functions of the sea ice bacterial community. While the roles of sea ice bacteria in the carbon cycle and sea ice microbial loop are evidenced by high rates of bacterial production (BP, their metabolic diversity extends far beyond heterotrophy, and their functionality encompasses much more than carbon turnover. Work over the last three decades has identified an active role for sea ice bacteria in phosphate and nitrogen cycling, mutualistic partnerships with ice algae, and even prokaryotic carbon fixation. To better understand the role of sea ice bacteria in the carbon cycle the existing sea ice BP and primary production data were synthesized. BP in sea ice was poorly correlated with primary production, but had a strong, variable relationship with chlorophyll a, with a positive correlation below 50 mg chlorophyll a m-3 and a negative correlation above this value. These results concur with previous work suggesting that BP can be inhibited by grazing or the production of bacteriostatic compounds. To extend existing observations and predictions of other community functions a metabolic inference technique was used on the available 16S rRNA gene data. This analysis provided taxonomic support for some observed metabolic processes, as well as underexplored processes such as sulfur oxidation and nitrogen fixation. The decreasing spatial and temporal extent of sea ice, and altered timing of ice formation and melt, are likely to impact the structure and function of sea ice bacterial communities. An adequate modeling framework and studies that can resolve the functional dynamics of the sea ice bacterial community, such as community gene expression studies, are urgently needed to predict future change.

  13. Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

    Nikolaev, A.G.; Yushkov, G.Yu.; Oks, E.M.; Oztarhan, A.; Akpek, A.; Hames-Kocabas, E.; Urkac, E.S.; Brown, I.G.

    2014-01-01

    Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material

  14. Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

    Nikolaev, A.G., E-mail: nik@opee.hcei.tsc.ru [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Yushkov, G.Yu.; Oks, E.M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Oztarhan, A. [Izmir University, Izmir 35140 (Turkey); Akpek, A.; Hames-Kocabas, E.; Urkac, E.S. [Bioengineering Department, Ege University, Bornova 35100, Izmir (Turkey); Brown, I.G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94708 (United States)

    2014-08-15

    Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material.

  15. ZnO nanostructures directly grown on paper and bacterial cellulose substrates without any surface modification layer.

    Costa, Saionara V; Gonçalves, Agnaldo S; Zaguete, Maria A; Mazon, Talita; Nogueira, Ana F

    2013-09-21

    In this report, hierarchical ZnO nano- and microstructures were directly grown for the first time on a bacterial cellulose substrate and on two additional different papers by hydrothermal synthesis without any surface modification layer. Compactness and smoothness of the substrates are two important parameters that allow the growth of oriented structures.

  16. Enzymatic modification of bacterial exopolysaccharides : xanthan lyase as a tool for structural and functional modification of xanthan

    Ruijssenaars, H.J.

    2001-01-01

    Bacterial extracellular polysaccharides (EPSs) can be applied, e.g., in foods, as a thickener or stabilizer. The functional properties that make a polysaccharide suitable for such applications are largely determined by the primary structure, i.e., the sugar composition, the linkage types

  17. A simple and novel modification of comet assay for determination of bacteriophage mediated bacterial cell lysis.

    Khairnar, Krishna; Sanmukh, Swapnil; Chandekar, Rajshree; Paunikar, Waman

    2014-07-01

    The comet assay is the widely used method for in vitro toxicity testing which is also an alternative to the use of animal models for in vivo testing. Since, its inception in 1984 by Ostling and Johansson, it is being modified frequently for a wide range of application. In spite of its wide applicability, unfortunately there is no report of its application in bacteriophages research. In this study, a novel application of comet assay for the detection of bacteriophage mediated bacterial cell lysis was described. The conventional methods in bacteriophage research for studying bacterial lysis by bacteriophages are plaque assay method. It is time consuming, laborious and costly. The lytic activity of bacteriophage devours the bacterial cell which results in the release of bacterial genomic material that gets detected by ethidium bromide staining method by the comet assay protocol. The objective of this study was to compare efficacy of comet assay with different assay used to study phage mediated bacterial lysis. The assay was performed on culture isolates (N=80 studies), modified comet assay appear to have relatively higher sensitivity and specificity than other assay. The results of the study showed that the application of comet assay can be an economical, time saving and less laborious alternative to conventional plaque assay for the detection of bacteriophage mediated bacterial cell lysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Influence of major-groove chemical modifications of DNA on transcription by bacterial RNA polymerases.

    Raindlová, Veronika; Janoušková, Martina; Slavíčková, Michaela; Perlíková, Pavla; Boháčová, Soňa; Milisavljevič, Nemanja; Šanderová, Hana; Benda, Martin; Barvík, Ivan; Krásný, Libor; Hocek, Michal

    2016-04-20

    DNA templates containing a set of base modifications in the major groove (5-substituted pyrimidines or 7-substituted 7-deazapurines bearing H, methyl, vinyl, ethynyl or phenyl groups) were prepared by PCR using the corresponding base-modified 2'-deoxyribonucleoside triphosphates (dNTPs). The modified templates were used in an in vitro transcription assay using RNA polymerase from Bacillus subtilis and Escherichia coli Some modified nucleobases bearing smaller modifications (H, Me in 7-deazapurines) were perfectly tolerated by both enzymes, whereas bulky modifications (Ph at any nucleobase) and, surprisingly, uracil blocked transcription. Some middle-sized modifications (vinyl or ethynyl) were partly tolerated mostly by the E. colienzyme. In all cases where the transcription proceeded, full length RNA product with correct sequence was obtained indicating that the modifications of the template are not mutagenic and the inhibition is probably at the stage of initiation. The results are promising for the development of bioorthogonal reactions for artificial chemical switching of the transcription. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Modification and Assembly of a Versatile Lactonase for Bacterial Quorum Quenching

    Melissa K. Rhoads

    2018-02-01

    Full Text Available This work sets out to provide a self-assembled biopolymer capsule activated with a multi-functional enzyme for localized delivery. This enzyme, SsoPox, which is a lactonase and phosphotriesterase, provides a means of interrupting bacterial communication pathways that have been shown to mediate pathogenicity. Here we demonstrate the capability to express, purify and attach SsoPox to the natural biopolymer chitosan, preserving its activity to “neutralize” long-chain autoinducer-1 (AI-1 communication molecules. Attachment is shown via non-specific binding and by engineering tyrosine and glutamine affinity ‘tags’ at the C-terminus for covalent linkage. Subsequent degradation of AI-1, in this case N-(3-oxododecanoyl-l-homoserine lactone (OdDHL, serves to “quench” bacterial quorum sensing (QS, silencing intraspecies communication. By attaching enzymes to pH-responsive chitosan that, in turn, can be assembled into various forms, we demonstrate device-based flexibility for enzyme delivery. Specifically, we have assembled quorum-quenching capsules consisting of an alginate inner core and an enzyme “decorated” chitosan shell that are shown to preclude bacterial QS crosstalk, minimizing QS mediated behaviors.

  20. Food-safe modification of stainless steel food processing surfaces to reduce bacterial biofilms.

    Awad, Tarek Samir; Asker, Dalal; Hatton, Benjamin D

    2018-06-11

    Biofilm formation on stainless steel (SS) surfaces of food processing plants, leading to foodborne illness outbreaks, is enabled by the attachment and confinement within microscale cavities of surface roughness (grooves, scratches). We report Foodsafe Oil-based Slippery Coatings (FOSCs) for food processing surfaces that suppress bacterial adherence and biofilm formation by trapping residual oil lubricant within these surface cavities to block microbial growth. SS surfaces were chemically functionalized with alkylphosphonic acid to preferentially wet a layer of food grade oil. FOSCs reduced the effective surface roughness, the adhesion of organic food residue, and bacteria. FOSCs significantly reduced Pseudomonas aeruginosa biofilm formation on standard roughness SS-316 by 5 log CFU cm-2, and by 3 log CFU cm-2 for mirror-finished SS. FOSCs also enhanced surface cleanability, which we measured by bacterial counts after conventional detergent cleaning. Importantly, both SS grades maintained their anti-biofilm activity after erosion of the oil layer by surface wear with glass beads, which suggests there is a residual volume of oil that remains to block surface cavity defects. These results indicate the potential of such low-cost, scalable approaches to enhance the cleanability of SS food processing surfaces and improve food safety by reducing biofilm growth.

  1. Bacterial exopolysaccharides as a modern biotechnological tool for modification of fungal laccase properties and metal ion binding.

    Osińska-Jaroszuk, Monika; Jaszek, Magdalena; Starosielec, Magdalena; Sulej, Justyna; Matuszewska, Anna; Janczarek, Monika; Bancerz, Renata; Wydrych, Jerzy; Wiater, Adrian; Jarosz-Wilkołazka, Anna

    2018-03-26

    Four bacterial EPSs extracted from Rhizobium leguminosarum bv. trifolii Rt24.2, Sinorhizobium meliloti Rm1021, Bradyrhizobium japonicum USDA110, and Bradyrhizobium elkanii USDA76 were determined towards their metal ion adsorption properties and possible modification of Cerrena unicolor laccase properties. The highest magnesium and iron ion-sorption capacity (~ 42 and ~ 14.5%, respectively) was observed for EPS isolated from B. japonicum USDA110. An evident influence of EPSs on the stability of laccase compared to the control values (without EPSs) was shown after 30-day incubation at 25 °C. The residual activity of laccases was obtained in the presence of Rh76EPS and Rh1021EPS, i.e., 49.5 and 41.5% of the initial catalytic activity, respectively. This result was confirmed by native PAGE electrophoresis. The EPS effect on laccase stability at different pH (from 3.8 to 7.0) was also estimated. The most significant changes at the optimum pH value (pH 5.8) was observed in samples of laccase stabilized by Rh76EPS and Rh1021EPS. Cyclic voltamperometry was used for analysis of electrochemical parameters of laccase stabilized by bacterial EPS and immobilized on single-walled carbon nanotubes (SWCNTs) with aryl residues. Laccases with Rh76EPS and Rh1021EPS had an evident shift of the value of the redox potential compared to the control without EPS addition. In conclusion, the results obtained in this work present a new potential use of bacterial EPSs as a metal-binding component and a modulator of laccase properties especially stability of enzyme activity, which can be a very effective tool in biotechnology and industrial applications.

  2. Modifications of γ-ray sensitivity of bacterial membranes by pre-exposure to light

    Misiti-Dorello, P.; Cancelliere, G.; De Martino, G.; Quintilini, M.

    1976-01-01

    The exposure of E. coli B/r cells to ultraviolet or to visible light prior to irradiation with γ-rays modifies the sensitivity of the cell membrane to radiation damage responsible for the intracellular K + content. Exposure of bacterial cells to sublethal doses of UV radiation increases their sensitivity to γ-induced membrane damage, while exposure to visible light has the opposite effect. In combined exposures, the visible light, either given before or after the UV always produces a strong photoprotective effect. In either case, the photosensitizing effect of UV is completely suppressed. The photoprotection decays with time if cell suspensions are left in the dark before γ-irradiation. At O 0 C, the half-life of the photoprotective effect is 25 min at pH 7 and 100 min at pH 7.5. The decay is due to the presence of oxygen. The light band responsible for the induction of photoprotection has been estimated to lie in the wavelenght region between 540 and 580 nm. (orig./MG) [de

  3. Photorhabdus adhesion modification protein (Pam) binds extracellular polysaccharide and alters bacterial attachment.

    Jones, Robert T; Sanchez-Contreras, Maria; Vlisidou, Isabella; Amos, Matthew R; Yang, Guowei; Muñoz-Berbel, Xavier; Upadhyay, Abhishek; Potter, Ursula J; Joyce, Susan A; Ciche, Todd A; Jenkins, A Toby A; Bagby, Stefan; Ffrench-Constant, Richard H; Waterfield, Nicholas R

    2010-05-12

    Photorhabdus are Gram-negative nematode-symbiotic and insect-pathogenic bacteria. The species Photorhabdus asymbiotica is able to infect humans as well as insects. We investigated the secreted proteome of a clinical isolate of P. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts. A comparison of the proteins secreted by a clinical isolate of P. asymbiotica at simulated insect (28 degrees C) and human (37 degrees C) temperatures led to the identification of a small and highly abundant protein, designated Pam, that is only secreted at the lower temperature. The pam gene is present in all Photorhabdus strains tested and shows a high level of conservation across the whole genus, suggesting it is both ancestral to the genus and probably important to the biology of the bacterium. The Pam protein shows limited sequence similarity to the 13.6 kDa component of a binary toxin of Bacillus thuringiensis. Nevertheless, injection or feeding of heterologously produced Pam showed no insecticidal activity to either Galleria mellonella or Manduca sexta larvae. In bacterial colonies, Pam is associated with an extracellular polysaccharide (EPS)-like matrix, and modifies the ability of wild-type cells to attach to an artificial surface. Interestingly, Surface Plasmon Resonance (SPR) binding studies revealed that the Pam protein itself has adhesive properties. Although Pam is produced throughout insect infection, genetic knockout does not affect either insect virulence or the ability of P. luminescens to form a symbiotic association with its host nematode, Heterorhabditis bacteriophora. We studied a highly abundant protein, Pam, which is secreted in a temperature-dependent manner in P. asymbiotica. Our findings indicate that Pam plays an important role in enhancing surface attachment in insect blood. Its association with exopolysaccharide suggests it may exert its effect through mediation of EPS properties. Despite

  4. Photorhabdus adhesion modification protein (Pam) binds extracellular polysaccharide and alters bacterial attachment

    Jones, Robert T

    2010-05-12

    Abstract Background Photorhabdus are Gram-negative nematode-symbiotic and insect-pathogenic bacteria. The species Photorhabdus asymbiotica is able to infect humans as well as insects. We investigated the secreted proteome of a clinical isolate of P. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts. Results A comparison of the proteins secreted by a clinical isolate of P. asymbiotica at simulated insect (28°C) and human (37°C) temperatures led to the identification of a small and highly abundant protein, designated Pam, that is only secreted at the lower temperature. The pam gene is present in all Photorhabdus strains tested and shows a high level of conservation across the whole genus, suggesting it is both ancestral to the genus and probably important to the biology of the bacterium. The Pam protein shows limited sequence similarity to the 13.6 kDa component of a binary toxin of Bacillus thuringiensis. Nevertheless, injection or feeding of heterologously produced Pam showed no insecticidal activity to either Galleria mellonella or Manduca sexta larvae. In bacterial colonies, Pam is associated with an extracellular polysaccharide (EPS)-like matrix, and modifies the ability of wild-type cells to attach to an artificial surface. Interestingly, Surface Plasmon Resonance (SPR) binding studies revealed that the Pam protein itself has adhesive properties. Although Pam is produced throughout insect infection, genetic knockout does not affect either insect virulence or the ability of P. luminescens to form a symbiotic association with its host nematode, Heterorhabditis bacteriophora. Conclusions We studied a highly abundant protein, Pam, which is secreted in a temperature-dependent manner in P. asymbiotica. Our findings indicate that Pam plays an important role in enhancing surface attachment in insect blood. Its association with exopolysaccharide suggests it may exert its effect through mediation of

  5. Photorhabdus adhesion modification protein (Pam binds extracellular polysaccharide and alters bacterial attachment

    Joyce Susan A

    2010-05-01

    Full Text Available Abstract Background Photorhabdus are Gram-negative nematode-symbiotic and insect-pathogenic bacteria. The species Photorhabdus asymbiotica is able to infect humans as well as insects. We investigated the secreted proteome of a clinical isolate of P. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts. Results A comparison of the proteins secreted by a clinical isolate of P. asymbiotica at simulated insect (28°C and human (37°C temperatures led to the identification of a small and highly abundant protein, designated Pam, that is only secreted at the lower temperature. The pam gene is present in all Photorhabdus strains tested and shows a high level of conservation across the whole genus, suggesting it is both ancestral to the genus and probably important to the biology of the bacterium. The Pam protein shows limited sequence similarity to the 13.6 kDa component of a binary toxin of Bacillus thuringiensis. Nevertheless, injection or feeding of heterologously produced Pam showed no insecticidal activity to either Galleria mellonella or Manduca sexta larvae. In bacterial colonies, Pam is associated with an extracellular polysaccharide (EPS-like matrix, and modifies the ability of wild-type cells to attach to an artificial surface. Interestingly, Surface Plasmon Resonance (SPR binding studies revealed that the Pam protein itself has adhesive properties. Although Pam is produced throughout insect infection, genetic knockout does not affect either insect virulence or the ability of P. luminescens to form a symbiotic association with its host nematode, Heterorhabditis bacteriophora. Conclusions We studied a highly abundant protein, Pam, which is secreted in a temperature-dependent manner in P. asymbiotica. Our findings indicate that Pam plays an important role in enhancing surface attachment in insect blood. Its association with exopolysaccharide suggests it may exert its effect

  6. Modulating the bacterial surface with small RNAs: a new twist on PhoP/Q-mediated lipopolysaccharide modification

    Overgaard, Martin; Kallipolitis, Birgitte; Valentin-Hansen, Poul

    2009-01-01

    Summary In recent years, small non-coding RNAs have emerged as important regulatory components in bacterial stress responses and in bacterial virulence. Many of these are conserved in related species and act on target mRNAs by sequence complementarity. They are tightly controlled at the transcrip...... in enterobacteria and reinforces the idea that one central role of bacterial small regulatory RNAs is to modulate and fine-tune cell surface composition and structure....

  7. Fever of unknown origin

    Misaki, Takashi; Matsui, Akira; Tanaka, Fumiko; Okuno, Yoshishige; Mitsumori, Michihide; Torizuka, Tatsurou; Dokoh, Shigeharu; Hayakawa, Katsumi; Shimbo, Shin-ichirou

    1990-01-01

    Gallium-67 scintigraphy is a commonly performed imaging modality in deteting pyrogenic lesions in cases of long-standing inexplainable fever. To re-evaluate the significance of gallium imaging in such cases, a retrospective review was made of 56 scans performed in febrile patients in whom sufficient clinical and laboratory findings were obtained. Gallium scans were true positive in 30 patients, false positive in 3, true negative in 19, and false negative in 4. In the group of true positive, local inflammatory lesions were detected in 23 patients with a final diagnosis of lung tuberculosis, urinary tract infection, and inflammatory joint disease. Abnormal gallium accumulation, as shown in the other 7 patients, provided clues to the diagnosis of generalized disorders, such as hematological malignancies (n=3), systemic autoimmune diseases (n=3), and severe infectious mononucleosis (n=one). In the group of false positive, gallium imaging revealed intestinal excretion of gallium in 2 patients and physiological pulmonary hilar accumulation in one. In the true negative group of 19 patients, fever of unknown origin was resolved spontaneously in 12 patients, and with antibiotics and corticosteroids in 2 and 5 patients, respectively. Four patients having false negative scans were finally diagnosed as having urinary tract infection (n=2), bacterial meningitis (n=one), and polyarteritis (n=one). Gallium imaging would remain the technique of choice in searching for origin of unknown fever. It may also be useful for early diagnosis of systemic disease, as well as focal inflammation. (N.K.)

  8. Anti-Bacterial and Anti-Fungal Activity of Xanthones Obtained via Semi-Synthetic Modification of α-Mangostin from Garcinia mangostana

    Srinivasan Narasimhan

    2017-02-01

    Full Text Available The microbial contamination in food packaging has been a major concern that has paved the way to search for novel, natural anti-microbial agents, such as modified α-mangostin. In the present study, twelve synthetic analogs were obtained through semi-synthetic modification of α-mangostin by Ritter reaction, reduction by palladium-carbon (Pd-C, alkylation, and acetylation. The evaluation of the anti-microbial potential of the synthetic analogs showed higher bactericidal activity than the parent molecule. The anti-microbial studies proved that I E showed high anti-bacterial activity whereas I I showed the highest anti-fungal activity. Due to their microbicidal potential, modified α-mangostin derivatives could be utilized as active anti-microbial agents in materials for the biomedical and food industry.

  9. Gut bacterial communities in the giant land snail Achatina fulica and their modification by sugarcane-based diet.

    Cardoso, Alexander M; Cavalcante, Janaína J V; Vieira, Ricardo P; Lima, Joyce L; Grieco, Maria Angela B; Clementino, Maysa M; Vasconcelos, Ana Tereza R; Garcia, Eloi S; de Souza, Wanderley; Albano, Rodolpho M; Martins, Orlando B

    2012-01-01

    The invasive land snail Achatina fulica is one of the most damaging agricultural pests worldwide representing a potentially serious threat to natural ecosystems and human health. This species is known to carry parasites and harbors a dense and metabolically active microbial community; however, little is known about its diversity and composition. Here, we assessed for the first time the complexity of bacterial communities occurring in the digestive tracts of field-collected snails (FC) by using culture-independent molecular analysis. Crop and intestinal bacteria in FC were then compared to those from groups of snails that were reared in the laboratory (RL) on a sugarcane-based diet. Most of the sequences recovered were novel and related to those reported for herbivorous gut. Changes in the relative abundance of Bacteroidetes and Firmicutes were observed when the snails were fed a high-sugar diet, suggesting that the snail gut microbiota can influence the energy balance equation. Furthermore, this study represents a first step in gaining a better understanding of land snail gut microbiota and shows that this is a complex holobiont system containing diverse, abundant and active microbial communities.

  10. Gut bacterial communities in the giant land snail Achatina fulica and their modification by sugarcane-based diet.

    Alexander M Cardoso

    Full Text Available The invasive land snail Achatina fulica is one of the most damaging agricultural pests worldwide representing a potentially serious threat to natural ecosystems and human health. This species is known to carry parasites and harbors a dense and metabolically active microbial community; however, little is known about its diversity and composition. Here, we assessed for the first time the complexity of bacterial communities occurring in the digestive tracts of field-collected snails (FC by using culture-independent molecular analysis. Crop and intestinal bacteria in FC were then compared to those from groups of snails that were reared in the laboratory (RL on a sugarcane-based diet. Most of the sequences recovered were novel and related to those reported for herbivorous gut. Changes in the relative abundance of Bacteroidetes and Firmicutes were observed when the snails were fed a high-sugar diet, suggesting that the snail gut microbiota can influence the energy balance equation. Furthermore, this study represents a first step in gaining a better understanding of land snail gut microbiota and shows that this is a complex holobiont system containing diverse, abundant and active microbial communities.

  11. Known knowns, known unknowns and unknown unknowns in prokaryotic transposition.

    Siguier, Patricia; Gourbeyre, Edith; Chandler, Michael

    2017-08-01

    Although the phenomenon of transposition has been known for over 60 years, its overarching importance in modifying and streamlining genomes took some time to recognize. In spite of a robust understanding of transposition of some TE, there remain a number of important TE groups with potential high genome impact and unknown transposition mechanisms and yet others, only recently identified by bioinformatics, yet to be formally confirmed as mobile. Here, we point to some areas of limited understanding concerning well established important TE groups with DDE Tpases, to address central gaps in our knowledge of characterised Tn with other types of Tpases and finally, to highlight new potentially mobile DNA species. It is not exhaustive. Examples have been chosen to provide encouragement in the continued exploration of the considerable prokaryotic mobilome especially in light of the current threat to public health posed by the spread of multiple Ab R . Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Function analysis of unknown genes

    Rogowska-Wrzesinska, A.

    2002-01-01

      This thesis entitled "Function analysis of unknown genes" presents the use of proteome analysis for the characterisation of yeast (Saccharomyces cerevisiae) genes and their products (proteins especially those of unknown function). This study illustrates that proteome analysis can be used...... to describe different aspects of molecular biology of the cell, to study changes that occur in the cell due to overexpression or deletion of a gene and to identify various protein modifications. The biological questions and the results of the described studies show the diversity of the information that can...... genes and proteins. It reports the first global proteome database collecting 36 yeast single gene deletion mutants and selecting over 650 differences between analysed mutants and the wild type strain. The obtained results show that two-dimensional gel electrophoresis and mass spectrometry based proteome...

  13. Tissue-specific expression and post-translational modifications of plant- and bacterial-type phosphoenolpyruvate carboxylase isozymes of the castor oil plant, Ricinus communis L.

    O’Leary, Brendan; Fedosejevs, Eric T.; Hill, Allyson T.; Bettridge, James; Park, Joonho; Rao, Srinath K.; Leach, Craig A.; Plaxton, William C.

    2011-01-01

    This study employs transcript profiling together with immunoblotting and co-immunopurification to assess the tissue-specific expression, protein:protein interactions, and post-translational modifications (PTMs) of plant- and bacterial-type phosphoenolpyruvate carboxylase (PEPC) isozymes (PTPC and BTPC, respectively) in the castor plant, Ricinus communis. Previous studies established that the Class-1 PEPC (PTPC homotetramer) of castor oil seeds (COS) is activated by phosphorylation at Ser-11 and inhibited by monoubiquitination at Lys-628 during endosperm development and germination, respectively. Elimination of photosynthate supply to developing COS by depodding caused the PTPC of the endosperm and cotyledon to be dephosphorylated, and then subsequently monoubiquitinated in vivo. PTPC monoubiquitination rather than phosphorylation is widespread throughout the castor plant and appears to be the predominant PTM of Class-1 PEPC that occurs in planta. The distinctive developmental patterns of PTPC phosphorylation versus monoubiquitination indicates that these two PTMs are mutually exclusive. By contrast, the BTPC: (i) is abundant in the inner integument, cotyledon, and endosperm of developing COS, but occurs at low levels in roots and cotyledons of germinated COS, (ii) shows a unique developmental pattern in leaves such that it is present in leaf buds and young expanding leaves, but undetectable in fully expanded leaves, and (iii) tightly interacts with co-expressed PTPC to form the novel and allosterically-desensitized Class-2 PEPC heteromeric complex. BTPC and thus Class-2 PEPC up-regulation appears to be a distinctive feature of rapidly growing and/or biosynthetically active tissues that require a large anaplerotic flux from phosphoenolpyruvate to replenish tricarboxylic acid cycle C-skeletons being withdrawn for anabolism. PMID:21841182

  14. Designing towards the unknown

    Wilde, Danielle; Underwood, Jenny

    2018-01-01

    the research potential to far-ranging possibilities. In this article we unpack the motivations driving the PKI project. We present our mixed-methodology, which entangles textile crafts, design interactions and materiality to shape an embodied enquiry. Our research outcomes are procedural and methodological......New materials with new capabilities demand new ways of approaching design. Destabilising existing methods is crucial to develop new methods. Yet, radical destabilisation—where outcomes remain unknown long enough that new discoveries become possible—is not easy in technology design where complex......, to design towards unknown outcomes, using unknown materials. The impossibility of this task is proving as useful as it is disruptive. At its most potent, it is destabilising expectations, aesthetics and processes. Keeping the researchers, collaborators and participants in a state of unknowing, is opening...

  15. [Badminton--unknown sport].

    Zekan-Petrinović, Lidija

    2007-01-01

    For a long time, badminton was considered to be only a slow and light game for children, a game that is played outdoors and is structurally undemanding.Today, it is not an unknown and unrecognised sport, especially after it was included into the Olympics Games in 1992. Badminton is one of the oldest sports in the world. It is suitable for all ages (for children and elderly equally), women and men and even handicapped persons. Beginners can start playing badminton matches early because the basics are learned quickly. As a recreational activity, badminton is very popular in Zagreb. In the last 10 years, a number of halls specialized for badminton or offering badminton as one of available sports activities have been opened in Zagreb. At present, there are over 70 professional playgrounds for training of top contestants but also for the citizens who can play recreational badminton.

  16. Recension: Mao - The Unknown Story

    Clausen, Søren

    2005-01-01

    Anmeldelse - kritisk! - til Sveriges førende Kinatidsskrift af Jung Chang & Jon Halliday's sensationelle "Mao - the Unknown Story".......Anmeldelse - kritisk! - til Sveriges førende Kinatidsskrift af Jung Chang & Jon Halliday's sensationelle "Mao - the Unknown Story"....

  17. Modifications in bacterial groups and short chain fatty acid production in the gut of healthy adult rats after long-term consumption of dietary Maillard reaction products.

    Delgado-Andrade, Cristina; Pastoriza de la Cueva, Silvia; Peinado, M Jesús; Rufián-Henares, José Ángel; Navarro, M Pilar; Rubio, Luis A

    2017-10-01

    Bread crust (BC) is one of the major sources of Maillard reaction products (MRPs) in the Western diet. This work was designed to analyze the impact of diets containing important levels of MRPs from BC on intestinal bacterial growth and short chain fatty acids (SCFAs) production in adult rats. Additionally, the pools of compounds excreted in feces attending to their molecular weights were analyzed. Rats were fed for 88days a control diet or diets containing BC or its soluble high molecular weight (HMW), soluble low molecular weight (LMW) or insoluble fractions, respectively. Intestinal (cecum) microbiota composition was determined by qPCR analysis. Consumption of the BC diet lowered (PMaillard reaction products are in vivo fermented by the gut microbiota, thereby changing both the pattern of SCFAs production and the microbiota composition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Endocarditis in adults with bacterial meningitis

    Lucas, Marjolein J.; Brouwer, Matthijs C.; van der Ende, Arie; van de Beek, Diederik

    2013-01-01

    Endocarditis may precede or complicate bacterial meningitis, but the incidence and impact of endocarditis in bacterial meningitis are unknown. We assessed the incidence and clinical characteristics of patients with meningitis and endocarditis from a nationwide cohort study of adults with

  19. Unknown foundation determination for scour.

    2012-04-01

    Unknown foundations affect about 9,000 bridges in Texas. For bridges over rivers, this creates a problem : regarding scour decisions as the calculated scour depth cannot be compared to the foundation depth, and a : very conservative costly approach m...

  20. Chemical Modification of a Dehydratase Enzyme Involved in Bacterial Virulence by an Ammonium Derivative: Evidence of its Active Site Covalent Adduct.

    González-Bello, Concepción; Tizón, Lorena; Lence, Emilio; Otero, José M; van Raaij, Mark J; Martinez-Guitian, Marta; Beceiro, Alejandro; Thompson, Paul; Hawkins, Alastair R

    2015-07-29

    The first example of an ammonium derivative that causes a specific modification of the active site of type I dehydroquinase (DHQ1), a dehydratase enzyme that is a promising target for antivirulence drug discovery, is described. The resolution at 1.35 Å of the crystal structure of DHQ1 from Salmonella typhi chemically modified by this ammonium derivative revealed that the ligand is covalently attached to the essential Lys170 through the formation of an amine. The detection by mass spectroscopy of the reaction intermediates, in conjunction with the results of molecular dynamics simulations, allowed us to explain the inhibition mechanism and the experimentally observed differences between S. typhi and Staphylococcus aureus enzymes. The results presented here reveal that the replacement of Phe225 in St-DHQ1 by Tyr214 in Sa-DHQ1 and its hydrogen bonding interaction with the conserved water molecule observed in several crystal structures protects the amino adduct against further dehydration/aromatization reactions. In contrast, for the St-DHQ1 enzyme, the carboxylate group of Asp114, with the assistance of this water molecule, would trigger the formation of a Schiff base that can undergo further dehydration reactions until full aromatization of the cyclohexane ring is achieved. Moreover, in vitro antivirulence studies showed that the reported compound is able to reduce the ability of Salmonella Enteritidis to kill A459 respiratory cells. These studies have identified a good scaffold for the design of irreversible inhibitors that can be used as drugs and has opened up new opportunities for the development of novel antivirulence agents by targeting the DHQ1 enzyme.

  1. Allocating monitoring effort in the face of unknown unknowns

    Wintle, B.A.; Runge, M.C.; Bekessy, S.A.

    2010-01-01

    There is a growing view that to make efficient use of resources, ecological monitoring should be hypothesis-driven and targeted to address specific management questions. 'Targeted' monitoring has been contrasted with other approaches in which a range of quantities are monitored in case they exhibit an alarming trend or provide ad hoc ecological insights. The second form of monitoring, described as surveillance, has been criticized because it does not usually aim to discern between competing hypotheses, and its benefits are harder to identify a priori. The alternative view is that the existence of surveillance data may enable rapid corroboration of emerging hypotheses or help to detect important 'unknown unknowns' that, if undetected, could lead to catastrophic outcomes or missed opportunities. We derive a model to evaluate and compare the efficiency of investments in surveillance and targeted monitoring. We find that a decision to invest in surveillance monitoring may be defensible if: (1) the surveillance design is more likely to discover or corroborate previously unknown phenomena than a targeted design and (2) the expected benefits (or avoided costs) arising from discovery are substantially higher than those arising from a well-planned targeted design. Our examination highlights the importance of being explicit about the objectives, costs and expected benefits of monitoring in a decision analytic framework. ?? 2010 Blackwell Publishing Ltd/CNRS.

  2. Financial Development and Economic Growth: Known Knowns, Known Unknowns, and Unknown Unknowns

    Ugo Panizza

    2014-01-01

    This paper summarizes the main findings of the literature on the relationship between financial and economic development (the known knowns), points to directions for future research (the known unknowns), and then speculates on the third Rumsfeldian category. The known knowns section organizes the empirical literature on finance and growth into three strands: (i) the traditional literature which established the link between finance and growth; (ii) the new literature which qualified some of th...

  3. Intraabdominal abscessus of unknown etiology

    Čolović Radoje

    2012-01-01

    Full Text Available Introduction. Intraabdominal abscesses are in 98-99% cases the result of secondary and only in 1-2% of primary peritonitis. They are easy and successfully diagnosed. Abdominal abscesses of unknown cause are extremely rare. Case Outline. The authors present a 68-year-old man, without significant data in past history, who suddenly developed epigastric pain, nausea, vomiting and leukocytosis which was treated with antibiotics resulting in the alleviation of complaints and reduction of white blood cells count. After five days ultrasonography showed incapsulated collection of dense fluid in the epigastrium confirmed by CT scan two days later. Upper endoscopy excluded ulcer and/or perforation of the stomach and duodenum. Under local anesthesia, through the upper part of the left rectal muscle, puncture followed by incision was done, and about 50 ml of dense pus was removed. Finger exploration of the cavity showed no foreign body within the cavity. Using drainage, the recovery was quick and uneventful. By preoperative and postoperative abdominal investigations no cause of the abscess was found. Two and a half years after surgery the patient remained symptom-free with normal clinical, laboratory and ultrasonographic findings. Conclusion. The authors presented an intraabdominal abscess of unknown cause that was successfully treated with antibiotics, percutaneous puncture and drainage under local anaesthesia. In spite of all diagnostic methods the cause of the abscess could not be found. Thus, such a possibility, although being rare, should be taken into account.

  4. [Focal myositis: An unknown disease].

    Gallay, L; Streichenberger, N; Benveniste, O; Allenbach, Y

    2017-10-01

    Focal myositis are inflammatory muscle diseases of unknown origin. At the opposite from the other idiopathic inflammatory myopathies, they are restricted to a single muscle or to a muscle group. They are not associated with extramuscular manifestations, and they have a good prognosis without any treatment. They are characterized by a localized swelling affecting mostly lower limbs. The pseudo-tumor can be painful, but is not associated with a muscle weakness. Creatine kinase level is normal. Muscle MRI shows an inflammation restricted to a muscle or a muscle group. Muscle biopsy and pathological analysis remain necessary for the diagnosis, showing inflammatory infiltrates composed by macrophages and lymphocytes without any specific distribution within the muscle. Focal overexpression of HLA-1 by the muscle fibers is frequently observed. The muscle biopsy permits to rule out differential diagnosis such a malignancy (sarcoma). Spontaneous remission occurs within weeks or months after the first symptoms, relapse is unusual. Copyright © 2017. Published by Elsevier SAS.

  5. Previously unknown species of Aspergillus.

    Gautier, M; Normand, A-C; Ranque, S

    2016-08-01

    The use of multi-locus DNA sequence analysis has led to the description of previously unknown 'cryptic' Aspergillus species, whereas classical morphology-based identification of Aspergillus remains limited to the section or species-complex level. The current literature highlights two main features concerning these 'cryptic' Aspergillus species. First, the prevalence of such species in clinical samples is relatively high compared with emergent filamentous fungal taxa such as Mucorales, Scedosporium or Fusarium. Second, it is clearly important to identify these species in the clinical laboratory because of the high frequency of antifungal drug-resistant isolates of such Aspergillus species. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been shown to enable the identification of filamentous fungi with an accuracy similar to that of DNA sequence-based methods. As MALDI-TOF MS is well suited to the routine clinical laboratory workflow, it facilitates the identification of these 'cryptic' Aspergillus species at the routine mycology bench. The rapid establishment of enhanced filamentous fungi identification facilities will lead to a better understanding of the epidemiology and clinical importance of these emerging Aspergillus species. Based on routine MALDI-TOF MS-based identification results, we provide original insights into the key interpretation issues of a positive Aspergillus culture from a clinical sample. Which ubiquitous species that are frequently isolated from air samples are rarely involved in human invasive disease? Can both the species and the type of biological sample indicate Aspergillus carriage, colonization or infection in a patient? Highly accurate routine filamentous fungi identification is central to enhance the understanding of these previously unknown Aspergillus species, with a vital impact on further improved patient care. Copyright © 2016 European Society of Clinical Microbiology and

  6. Bacterial meningitis

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  7. Chinese Unknown Word Recognition for PCFG-LA Parsing

    Qiuping Huang

    2014-01-01

    Full Text Available This paper investigates the recognition of unknown words in Chinese parsing. Two methods are proposed to handle this problem. One is the modification of a character-based model. We model the emission probability of an unknown word using the first and last characters in the word. It aims to reduce the POS tag ambiguities of unknown words to improve the parsing performance. In addition, a novel method, using graph-based semisupervised learning (SSL, is proposed to improve the syntax parsing of unknown words. Its goal is to discover additional lexical knowledge from a large amount of unlabeled data to help the syntax parsing. The method is mainly to propagate lexical emission probabilities to unknown words by building the similarity graphs over the words of labeled and unlabeled data. The derived distributions are incorporated into the parsing process. The proposed methods are effective in dealing with the unknown words to improve the parsing. Empirical results for Penn Chinese Treebank and TCT Treebank revealed its effectiveness.

  8. Bacterial prostatitis.

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  9. Bacterial Vaginosis

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  10. BACTERIAL CONSORTIUM

    Payel Sarkar

    2013-01-01

    Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

  11. Quantum circuits cannot control unknown operations

    Araújo, Mateus; Feix, Adrien; Costa, Fabio; Brukner, Časlav

    2014-01-01

    One of the essential building blocks of classical computer programs is the ‘if’ clause, which executes a subroutine depending on the value of a control variable. Similarly, several quantum algorithms rely on applying a unitary operation conditioned on the state of a control system. Here we show that this control cannot be performed by a quantum circuit if the unitary is completely unknown. The task remains impossible even if we allow the control to be done modulo a global phase. However, this no-go theorem does not prevent implementing quantum control of unknown unitaries in practice, as any physical implementation of an unknown unitary provides additional information that makes the control possible. We then argue that one should extend the quantum circuit formalism to capture this possibility in a straightforward way. This is done by allowing unknown unitaries to be applied to subspaces and not only to subsystems. (paper)

  12. Multifocal, chronic osteomyelitis of unknown etiology

    Kozlowski, K.; Beluffi, G.; Feltham, C.; James, M.; Nespoli, L.; Tamaela, L.; Pavia Univ.; Municipal Hospital, Nelson; Medical School, Jakarta

    1985-01-01

    Four cases of multifocal osteomyelitis of unknown origin in childhood are reported. The variable clinical and radiographic appearances of the disease are illustrated and the diagnostic difficulties in the early stages of the disease are stressed. (orig.) [de

  13. Known Unknowns in Judgment and Choice

    Walters, Daniel

    2017-01-01

    This dissertation investigates how people make inferences about missing information. Whereas most prior literature focuses on how people process known information, I show that the extent to which people make inferences about missing information impacts judgments and choices. Specifically, I investigate how (1) awareness of known unknowns affects overconfidence in judgment in Chapter 1, (2) beliefs about the knowability of unknowns impacts investment strategies in Chapter 2, and (3) inferences...

  14. Mobile assistant for unknown caller identification

    Hribernik, Andraž

    2012-01-01

    The main motivation of this diploma thesis is a development of Android application, which helps user of application to find out who is the owner of unknown phone number. Data source for finding unknown phone number are free available web sources. Through the development of prototype, data from different web sources were integrated. Result of this integration is shown in Android application. Data integration includes access to semi-structured data on web portal of Phone Directory of Slovenia, ...

  15. Bacterial Adhesion & Blocking Bacterial Adhesion

    Vejborg, Rebecca Munk

    2008-01-01

    , which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters...

  16. Bacterial meningitis

    Heckenberg, Sebastiaan G. B.; Brouwer, Matthijs C.; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained,

  17. Bacterial lipases

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation,

  18. Bacterial stress

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  19. Protocol for counterfactually transporting an unknown qubit

    Hatim eSalih

    2016-01-01

    Full Text Available Quantum teleportation circumvents the uncertainty principle using dual channels: a quantum one consisting of previously-shared entanglement, and a classical one, together allowing the disembodied transport of an unknown quantum state over distance. It has recently been shown that a classical bit can be counterfactually communicated between two parties in empty space, Alice and Bob. Here, by using our dual version of the chained quantum Zeno effect to achieve a counterfactual CNOT gate, we propose a protocol for transporting an unknown qubit counterfactually, that is without any physical particles travelling between Alice and Bob—no classical channel and no previously-shared entanglement.

  20. [Bacterial vaginosis].

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  1. Modified niche optima and breadths explain the historical contingency of bacterial community responses to eutrophication in coastal sediments

    Fodelianakis, Stylianos

    2016-09-23

    Previous studies have shown that the response of bacterial communities to disturbances depends on their environmental history. Historically fluctuating habitats host communities that respond better to disturbance than communities of historically stable habitats. However, the exact ecological mechanism that drives this dependency remains unknown. Here, we experimentally demonstrate that modifications of niche optima and niche breadths of the community members are driving this dependency of bacterial responses to past environmental conditions. First, we develop a novel, simple method to calculate the niche optima and breadths of bacterial taxa regarding single environmental gradients. Then, we test this method on sediment bacterial communities of three habitats, one historically stable and less loaded and two historically more variable and more loaded habitats in terms of historical chlorophyll-α water concentration, that we subject to hypoxia via organic matter addition ex situ. We find that communities containing bacterial taxa differently adapted to hypoxia show different structural and functional responses, depending on the sediment\\'s environmental history. Specifically, in the historically less fluctuating and loaded sediments where we find more taxa poorly adapted to hypoxic conditions, communities change a lot over time and organic matter is not degraded efficiently. The opposite is true for the historically more fluctuating and loaded sediments where we find more taxa well adapted to hypoxia. Based on the community responses observed here, we also propose an alternative calculation of community resistance that takes into account how rapidly the communities respond to disturbances and not just the initial and final states of the community.

  2. Multifocal chronic osteomyelitis of unknown etiology

    Kozlowski, K.; Masel, J.; Harbison, S.; Yu, J.; Royal Brisbane Children Hospital; Regional Hospital Bowral

    1983-01-01

    Five cases of chronic, inflammatory, multifocal bone lesions of unknown etiology are reported. Although bone biopsy confirmed osteomyelitis in each case in none of them were organisms found inspite of an extensive work up. Different clinical course of the disease reflects different aetiology in respective cases. These cases present changing aspects of osteomyelitis emerging since introduction of antibiotics. (orig.)

  3. Bacterial mitosis

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...

  4. Characterization of resistant tomato mutants to bacterial canker ...

    Yomi

    2012-04-19

    Apr 19, 2012 ... Cmm bacteria induce bacterial canker and wilt during infection. It is unknown ... are able to degrade plant cell walls and attack xylem vessels and ... seedlings were transferred into plastic pots at four to five true leaf stages.

  5. Melanoma of unknown origin: a case series.

    Kelly, J

    2010-12-01

    The natural history of metastatic melanoma involving lymph nodes, in the absence of a known primary site (cutaneous, ocular or mucosal) has, to date, been poorly defined; and the optimal management of this rare subtype of disease is therefore unclear. Melanomas of unknown primary site (MUP) are estimated to comprise between 3.7 and 6% of all melanomas (Anbari et al. in Cancer 79:1861-1821, 1997).

  6. Autonomous Flight in Unknown Indoor Environments

    Bachrach, Abraham Galton; He, Ruijie; Roy, Nicholas

    2009-01-01

    This paper presents our solution for enabling a quadrotor helicopter, equipped with a laser rangefinder sensor, to autonomously explore and map unstructured and unknown indoor environments. While these capabilities are already commodities on ground vehicles, air vehicles seeking the same performance face unique challenges. In this paper, we describe the difficulties in achieving fully autonomous helicopter flight, highlighting the differences between ground and helicopter robots that make it ...

  7. Multidimensional procurement auctions with unknown weights

    Greve, Thomas

    This paper studies the consequences of holding a procurement auction when the principal chooses not to show its preferences. My paper extends the procurement auction model of Che (1993) to a situation where both the principal and the agents have private information. Thus, unknown parameters of bo...... gives rise to an analysis of a principal that can not fully commit to the outcome induced by the scoring rule. Therefore, my result apply to contract theory and it’s problems with imperfect commitment....

  8. Invariant amino acids in the Mur peptide synthetases of bacterial peptidoglycan synthesis and their modification by site-directed mutagenesis in the UDP-MurNAc:L-alanine ligase from Escherichia coli.

    Bouhss, A; Mengin-Lecreulx, D; Blanot, D; van Heijenoort, J; Parquet, C

    1997-09-30

    The comparison of the amino acid sequences of 20 cytoplasmic peptidoglycan synthetases (MurC, MurD, MurE, MurF, and Mpl) from various bacterial organisms has allowed us to detect common invariants: seven amino acids and the ATP-binding consensus sequence GXXGKT/S all at the same position in the alignment. The Mur synthetases thus appeared as a well-defined class of closely functionally related proteins. The conservation of a constant backbone length between certain invariants suggested common structural motifs. Among the other enzymes catalyzing a peptide bond formation driven by ATP hydrolysis to ADP and Pi, only folylpoly-gamma-l-glutamate synthetases presented the same common conserved amino acid residues, except for the most N-terminal invariant D50. Site-directed mutageneses were carried out to replace the K130, E174, H199, N293, N296, R327, and D351 residues by alanine in the MurC protein from Escherichia coli taken as model. For this purpose, plasmid pAM1005 was used as template, MurC being highly overproduced in this genetic setting. Analysis of the Vmax values of the mutated proteins suggested that residues K130, E174, and D351 are essential for the catalytic process whereas residues H199, N293, N296, and R327 were not. Mutations K130A, H199A, N293A, N296A, and R327A led to important variations of the Km values for one or more substrates, thereby indicating that these residues are involved in the structure of the active site and suggesting that the binding order of the substrates could be ATP, UDP-MurNAc, and alanine. The various mutated murC plasmids were tested for their effects on the growth, cell morphology, and peptidoglycan cell content of a murC thermosensitive strain at 42 degrees C. The observed effects (complementation, altered morphology, and reduced peptidoglycan content) paralleled more or less the decreased values of the MurC activity of each mutant.

  9. Bacterial Ecology

    Fenchel, Tom

    2011-01-01

    compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example......, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  10. DNA Phosphorothioate Modification Plays a Role in Peroxides Resistance in Streptomyces lividans

    Daofeng Dai

    2016-08-01

    Full Text Available DNA phosphorothioation, conferred by dnd genes, was originally discovered in the soil-dwelling bacterium Streptomyces lividans, and thereafter found to exist in various bacterial genera. However, the physiological significance of this sulfur modification of the DNA backbone remains unknown in S. lividans. Our studies indicate that DNA phosphorothioation has a major role in resistance to oxidative stress in the strain. Although Streptomyces species express multiple catalase/peroxidase and organic hydroperoxide resistance genes to protect them against peroxide damage, a wild type strain of S. lividans exhibited two-fold to 10-fold higher survival, compared to a dnd- mutant, following treatment with peroxides. RNA-seq experiments revealed that, catalase and organic hydroperoxide resistance gene expression were not up-regulated in the wild type strain, suggesting that the resistance to oxidative stress was not due to the up-regulation of these genes by DNA phosphorothioation. Quantitative RT-PCR analysis was conducted to trace the expression of the catalase and the organic hydroperoxide resistance genes after peroxides treatments. A bunch of these genes were activated in the dnd- mutant rather than the wild type strain in response to peroxides. Moreover, the organic hydroperoxide peracetic acid was scavenged more rapidly in the presence than in the absence of phosphorothioate modification, both in vivo and in vitro. The dnd gene cluster can be up-regulated by the disulfide stressor diamide. Overall, our observations suggest that DNA phosphorothioate modification functions as a peroxide resistance system in S. lividans.

  11. Bacterial Actins.

    Izoré, Thierry; van den Ent, Fusinita

    2017-01-01

    A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.

  12. Selected topics from classical bacterial genetics.

    Raleigh, Elisabeth A; Elbing, Karen; Brent, Roger

    2002-08-01

    Current cloning technology exploits many facts learned from classical bacterial genetics. This unit covers those that are critical to understanding the techniques described in this book. Topics include antibiotics, the LAC operon, the F factor, nonsense suppressors, genetic markers, genotype and phenotype, DNA restriction, modification and methylation and recombination.

  13. TOURISM PROMOTION FOR UNKNOWN AREAS IN ROMANIA

    Fotache Lacramioara

    2013-12-01

    Full Text Available The paper is an effort to unknown areas identity affirmation, through collaborative development of advertising mix, with an emphasis on virtual platforms as admissible solution for increasing visibility. Based upon comparative effective analysis of categories of communication particularities, it is suggested a positioning strategic solution, via virtual advertising platform as unique, integrated, complex and very attractive tourism product promotion, fitted for the internal and international tourism circuit. The active promotion of the specified territorial identity will launch a brand with an impact among tourists by using marketing techniques and innovating technical means and prioritizing tourism as a principal vector of local and regional development.

  14. Metastasis to neck from unknown primary tumor

    Jose, B.; Bosch, A.; Caldwell, W.L.; Frias, Z.

    1979-01-01

    The records of 54 consecutive patients who were irradiated for metastatic disease in the neck from an unknown primary tumor were reviewed. The overall survival results are comparable to those of other reported series. Patients with high or posterior cervical lymph node involvement were irradiated with fields including the nasopharynx and oropharynx. Patients with high neck nodes had a better survival rate than those with low neck nodes. The size of the neck tumors and the local control after treatment also have prognostic significance. (Auth.)

  15. Twelve previously unknown phage genera are ubiquitous in global oceans.

    Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh; Corrier, Kristen; Riemann, Lasse; Verberkmoes, Nathan C; Sullivan, Matthew B

    2013-07-30

    Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.

  16. Community-acquired purulent meningitis of unknown etiology. A continuing problem.

    Geiseler, P J; Nelson, K E; Levin, S

    1981-12-01

    The clinical features and hospital course of 132 patients with purulent meningitis of unknown etiology (PMU) were compared with those of 1,032 patients with proven bacterial meningitis; all patients were admitted to a major referral center for meningitis treatment between 1954 and 1976. Most patients had no major underlying illnesses. Patients with PMU were more frequently older, "pretreated" with antibiotics, had longer duration of symptoms, evidenced less marked alterations of mental status, and died later in the hospitalization; however, the mortality and frequency of neurologic complications were similar to those in patients with bacterial meningitis. Patients with PMU who also had hemorrhagic rashes had fewer neurologic complications and none died; these patients comprised a distinct group in terms of better prognosis. New methods for rapid diagnosis of bacterial meningitis have only partially resolved the diagnostic dilemma of PMU.

  17. Rare occurrence of heart lesions in Pacific oysters Crassostrea gigas caused by an unknown bacterial infection.

    Meyer, Gary R; Lowe, Geoffrey J; Bower, Susan M

    2017-09-20

    On rare occasions, small cream-coloured cysts have been observed in the heart and pericardial cavity of Pacific oysters Crassostrea gigas from British Columbia, Canada. Histopathology revealed the presence of large colonies of bacteria (up to 800 µm in diameter) causing significant host response and hypertrophy of the heart epithelium. The causative bacteria were characterized as follows: Gram-negative, coccoid to small rod-shaped, typically <1.5 µm in size, cell walls highly endowed with surface fimbriae and division via binary fission. Although these bacteria shared some morphological characteristics with the order Rickettsiales, they did not require an intracellular existence for multiplication. Unfortunately, a cultured isolate was not available, and a retrospective attempt to further characterize the bacteria using DNA sequence analysis of a fragment from the 16S rDNA region proved to be uninformative.

  18. Challenges of the Unknown: Clinical Application of Microbial Metagenomics

    Graham Rose

    2015-01-01

    Full Text Available Availability of fast, high throughput and low cost whole genome sequencing holds great promise within public health microbiology, with applications ranging from outbreak detection and tracking transmission events to understanding the role played by microbial communities in health and disease. Within clinical metagenomics, identifying microorganisms from a complex and host enriched background remains a central computational challenge. As proof of principle, we sequenced two metagenomic samples, a known viral mixture of 25 human pathogens and an unknown complex biological model using benchtop technology. The datasets were then analysed using a bioinformatic pipeline developed around recent fast classification methods. A targeted approach was able to detect 20 of the viruses against a background of host contamination from multiple sources and bacterial contamination. An alternative untargeted identification method was highly correlated with these classifications, and over 1,600 species were identified when applied to the complex biological model, including several species captured at over 50% genome coverage. In summary, this study demonstrates the great potential of applying metagenomics within the clinical laboratory setting and that this can be achieved using infrastructure available to nondedicated sequencing centres.

  19. Adresse inconnue / Address unknown / Suchwiin Bulmyeong

    Serge Gruzinski

    2005-03-01

    Full Text Available Tous les films asiatiques parlent de métissage, même ceux qui se présentent comme de vastes fresques historiques perdues dans le temps. Les emprunts aux traditions hollywoodiennes et européennes n'ont cessé d'enrichir une cinématographie aussi ancienne que celle du monde occidental. Dans Adresse inconnue (Address unknown le cinéaste coréen Kim Ki-duk explore l'expérience du métissage et le corps du métis à la frontière entre Corée du Nord et Corée du sud. Fils d'un GI américain et noir et d...

  20. Adresse inconnue / Address unknown / Suchwiin Bulmyeong

    Serge Gruzinski

    2005-01-01

    Tous les films asiatiques parlent de métissage, même ceux qui se présentent comme de vastes fresques historiques perdues dans le temps. Les emprunts aux traditions hollywoodiennes et européennes n'ont cessé d'enrichir une cinématographie aussi ancienne que celle du monde occidental. Dans Adresse inconnue (Address unknown) le cinéaste coréen Kim Ki-duk explore l'expérience du métissage et le corps du métis à la frontière entre Corée du Nord et Corée du sud. Fils d'un GI américain et noir et d'...

  1. The Unknown Component Problem Theory and Applications

    Villa, Tiziano; Brayton, Robert K; Mishchenko, Alan; Petrenko, Alexandre; Sangiovanni-Vincentelli, Alberto

    2012-01-01

    The Problem of the Unknown Component: Theory and Applications addresses the issue of designing a component that, combined with a known part of a system, conforms to an overall specification. The authors tackle this problem by solving abstract equations over a language. The most general solutions are studied when both synchronous and parallel composition operators are used. The abstract equations are specialized to languages associated with important classes of automata used for modeling systems. The book is a blend of theory and practice, which includes a description of a software package with applications to sequential synthesis of finite state machines. Specific topologies interconnecting the components, exact and heuristic techniques, and optimization scenarios are studied. Finally the scope is enlarged to domains like testing, supervisory control, game theory and synthesis for special omega languages. The authors present original results of the authors along with an overview of existing ones.

  2. Carcinomatous Meningitis from Unknown Primary Carcinoma

    L. Favier

    2009-10-01

    Full Text Available Carcinomatous meningitis (CM occurs in 3 to 8% of cancer patients. Patients present with a focal symptom, and multifocal signs are often found following neurological examination. The gold standard for diagnosis remains the demonstration of carcinomatous cells in the cerebrospinal fluid on cytopathological examination. Despite the poor prognosis, palliative treatment could improve quality of life and, in some cases, overall survival. We report on a patient who presented with vertigo, tinnitus and left-sided hearing loss followed by progressive diffuse facial nerve paralysis. Lumbar cerebrospinal fluid confirmed the diagnosis of CM. However, no primary tumor was discovered, even after multiple invasive investigations. This is the first reported case in the English-language medical literature of CM resulting from a carcinoma of unknown primary origin.

  3. Education Through Exploration: Evaluating the Unknown

    Anbar, A. D.

    2015-12-01

    Mastery of the peculiar and powerful practices of science is increasingly important for the average citizen. With the rise of the Internet, most of human knowledge is at our fingertips. As content becomes a commodity, success and survival aren't about who knows the most, but who is better able to explore the unknown, actively applying and extending knowledge through critical thinking and hypothesis-driven problem-solving. This applies to the economic livelihoods of individuals and to society at large as we grapple with climate change and other science-infused challenges. Unfortunately, science is too often taught as an encyclopedic collection of settled facts to be mastered rather than as a process of exploration that embraces curiosity, inquiry, testing, and communication to reduce uncertainty about the unknown. This problem is exacerbated by the continued prevalence of teacher-centric pedagogy, which promotes learning-from-authority and passive learning. The initial wave of massively open online courses (MOOCs) generally mimic this teaching style in virtual form. It is hypothesized that emerging digital teaching technologies can help address this challenge at Internet scale in "next generation" MOOCs and flipped classroom experiences. Interactive simulations, immersive virtual field trips, gamified elements, rapid adaptive feedback, intelligent tutoring systems, and personalized pathways, should motivate and enhance learning. Through lab-like projects and tutorials, students should be able to construct knowledge from interactive experiences, modeling the authentic practice of science while mastering complex concepts. Freed from lecturing, teaching staff should be available for direct and intense student-teacher interactions. These claims are difficult to evaluate with traditional assessment instruments, but digital technologies provide powerful new ways to evaluate student learning and learn from student behaviors. We will describe ongoing experiences with such

  4. Behavior Modification in Coaching.

    Lynch, Annette Rutt; Stillman, Stephen M.

    1979-01-01

    An example of behavior modification used in athletic coaching is presented. The case study involves a member of a women's basketball team and details the use of behavior modification for both weight reduction and skill improvement. (JMF)

  5. PMS2 monoallelic mutation carriers: the known unknown.

    Goodenberger, McKinsey L; Thomas, Brittany C; Riegert-Johnson, Douglas; Boland, C Richard; Plon, Sharon E; Clendenning, Mark; Win, Aung Ko; Senter, Leigha; Lipkin, Steven M; Stadler, Zsofia K; Macrae, Finlay A; Lynch, Henry T; Weitzel, Jeffrey N; de la Chapelle, Albert; Syngal, Sapna; Lynch, Patrick; Parry, Susan; Jenkins, Mark A; Gallinger, Steven; Holter, Spring; Aronson, Melyssa; Newcomb, Polly A; Burnett, Terrilea; Le Marchand, Loïc; Pichurin, Pavel; Hampel, Heather; Terdiman, Jonathan P; Lu, Karen H; Thibodeau, Stephen; Lindor, Noralane M

    2016-01-01

    Germ-line mutations in MLH1, MSH2, MSH6, and PMS2 have been shown to cause Lynch syndrome. The penetrance of the cancer and tumor spectrum has been repeatedly studied, and multiple professional societies have proposed clinical management guidelines for affected individuals. Several studies have demonstrated a reduced penetrance for monoallelic carriers of PMS2 mutations compared with the other mismatch repair (MMR) genes, but clinical management guidelines have largely proposed the same screening recommendations for all MMR gene carriers. The authors considered whether enough evidence existed to propose new screening guidelines specific to PMS2 mutation carriers with regard to age at onset and frequency of colonic screening. Published reports of PMS2 germ-line mutations were combined with unpublished cases from the authors' research registries and clinical practices, and a discussion of potential modification of cancer screening guidelines was pursued. A total of 234 monoallelic PMS2 mutation carriers from 170 families were included. Approximately 8% of those with colorectal cancer (CRC) were diagnosed before age 30, and each of these tumors presented on the left side of the colon. As it is currently unknown what causes the early onset of CRC in some families with monoallelic PMS2 germline mutations, the authors recommend against reducing cancer surveillance guidelines in families found having monoallelic PMS2 mutations in spite of the reduced penetrance.Genet Med 18 1, 13-19.

  6. A survey of Type III restriction-modification systems reveals numerous, novel epigenetic regulators controlling phase-variable regulons; phasevarions

    Atack, John M; Yang, Yuedong; Jennings, Michael P

    2018-01-01

    Abstract Many bacteria utilize simple DNA sequence repeats as a mechanism to randomly switch genes on and off. This process is called phase variation. Several phase-variable N6-adenine DNA-methyltransferases from Type III restriction-modification systems have been reported in bacterial pathogens. Random switching of DNA methyltransferases changes the global DNA methylation pattern, leading to changes in gene expression. These epigenetic regulatory systems are called phasevarions — phase-variable regulons. The extent of these phase-variable genes in the bacterial kingdom is unknown. Here, we interrogated a database of restriction-modification systems, REBASE, by searching for all simple DNA sequence repeats in mod genes that encode Type III N6-adenine DNA-methyltransferases. We report that 17.4% of Type III mod genes (662/3805) contain simple sequence repeats. Of these, only one-fifth have been previously identified. The newly discovered examples are widely distributed and include many examples in opportunistic pathogens as well as in environmental species. In many cases, multiple phasevarions exist in one genome, with examples of up to 4 independent phasevarions in some species. We found several new types of phase-variable mod genes, including the first example of a phase-variable methyltransferase in pathogenic Escherichia coli. Phasevarions are a common epigenetic regulation contingency strategy used by both pathogenic and non-pathogenic bacteria. PMID:29554328

  7. High Valence, Normal Valence and Unknown Valence

    Morsing, Thorbjørn Juul

    the serendipitous synthesis of the nitrido-bridged [Rh(en)3]2- [(CN)5MnNMn(CN)5]. The complex anion have previously been studied in the form of the mixed Rb4Na2-salt. In this earlier study, the nitrido-bridge was found to be asymmetrical with the axial ligands in an eclipsed formation. The complex was described...... the [Rh(en)3]2-salt is best described as Mn3.5/Mn3.5. This means that the [(CN)5MnNMn(CN)5]6􀀀 ion displays crystal packing induced oxidation state isomerism, a rare phenomenon. Chapter 4 details the synthesis and characterisation of group 9 dithiolene complexes with focus on the hitherto unknown...... homoleptic iridium dithiolene complexes. When the complexes [M(mnt)3]3􀀀, M = Rh and Co are chemically oxidized, they decompose to yield dinuclear complexes with the metal still in oxidation state III. This is not the case for the corresponding Ir complex which can be oxidized and the oxidation...

  8. Lung Lesions During Fever of Unknown Origin.

    Krupa, Renata; Zielonka, Tadeusz M; Hadzik-Blaszczyk, Malgorzata; Wardyn, Kazimierz A; Zycinska, Katarzyna

    2017-01-01

    Fever of unknown origin (FUO) remains one of the most difficult diagnostic challenges. The causes of FUO can be various diseases located in different organs. The aim of the study was to determine the prevalence and nature of pulmonary lesions during FUO. One hundred and sixty one patients with FUO participated in this prospective study. We performed a detailed comprehensive history, physical examination, and a wide spectrum of tests. The most common causes of FUO were infections (39%), autoimmune conditions (28%), and neoplasms (17%). Lung lesions were found in 30% of patients. In this group 35% were infections, 30% autoimmune diseases, and 4% cancer. Among patients with respiratory infections, there were cases of tuberculosis, atypical pneumonia, lung abscess, and bronchiectases. Autoimmune pulmonary lesions were observed during vasculitis and systemic lupus. The causes of FUO in the group of patients with lung lesions were also pulmonary embolism, sarcoidosis, and pulmonary fibrosis. Chest CT played an important role in the diagnosis of the causes of FUO with pulmonary manifestations. Pulmonary lesions are a common cause of FUO. Most FUO with pulmonary lesions are recognized during infections and autoimmune diseases. An important part of diagnosing FUO is a detailed evaluation of the respiratory system.

  9. Unknown Risks: Parental Hesitation about Vaccination.

    Blaisdell, Laura L; Gutheil, Caitlin; Hootsmans, Norbert A M; Han, Paul K J

    2016-05-01

    This qualitative study of a select sample of vaccine-hesitant parents (VHPs) explores perceived and constructed personal judgments about the risks and uncertainties associated with vaccines and vaccine-preventable diseases (VPDs) and how these subjective risk judgments influence parents' decisions about childhood vaccination. The study employed semistructured focus group interviews with 42 VHPs to elicit parents' perceptions and thought processes regarding the risks associated with vaccination and nonvaccination, the sources of these perceptions, and their approach to decision making about vaccination for their children. VHPs engage in various reasoning processes and tend to perceive risks of vaccination as greater than the risks of VPDs. At the same time, VHPs engage in other reasoning processes that lead them to perceive ambiguity in information about the harms of vaccination-citing concerns about the missing, conflicting, changing, or otherwise unreliable nature of information. VHPs' refusal of vaccination may reflect their aversion to both the risk and ambiguity they perceive to be associated with vaccination. Mitigating this vaccine hesitancy likely requires reconstructing the risks and ambiguities associated with vaccination-a challenging task that requires providing parents with meaningful evidence-based information on the known risks of vaccination versus VPDs and explicitly acknowledging the risks that remain truly unknown. © The Author(s) 2015.

  10. The energy equation with three unknowns

    Schifano, Fabio; Moriconi, Daniele

    2008-01-01

    This article discusses the alarming situation of energy in Italy as this country depends at 82 per cent on its imports (oil, natural gas and electricity), a dependence which could even increase. The authors first propose overviews of the situation regarding oil, natural gas and electric power (origins of imports, role of Italian companies, status of infrastructures), and also briefly of renewable energies. They recall the history of the use of nuclear energy: Italy has been one of the first country to use nuclear energy to produce electric power, but a referendum organised after Chernobyl resulted in phasing out nuclear. Then, the authors discuss perspectives associated with three main strategic unknowns: an increase of energy dependence with respect to hydrocarbons and to foreign nuclear power, a supply insecurity due to a dependence concentrated on a small number of countries (notably as far as natural gas is concerned), and an increasing interdependence between economic growth and sustainable development (the reduction of greenhouse emissions is a prevailing parameter for future energetic choices)

  11. Uric Acid: The Unknown Uremic Toxin.

    Treviño-Becerra, Alejandro

    2018-01-01

    This review brings together concepts of uric acid metabolism affecting renal parenchyma and its function and the current therapies to reduce hyperuricemia (HyU) and avoid renal disease progression. High uric acid plays an important role in several chronic diseases including kidney diseases such as lithiasis, gout nephropathy, and preeclampsia. In the last 30 years, it has been shown that reducing HyU with low protein and low purine diets in addition to allopurinol creates physiopathological conditions that produce a slight increase in the glomerular filtration rate (GFR). In recent years, in a new era of research in clinical, genetics, pharmacological, and epidemiologic fields, they have been moving forward to support the idea that reduction in HyU could benefit the chronic renal failure (CRF) patients (stage III-IV), thereby avoiding the drop of GFR for undefined mechanisms. There are several clinical trials in progress that show the HyU reducing to very low values and an increased GFR. In a young population, when treating HyU there is a reduction in high blood pressure. There are some reports showing that HyU could play a role in the diabetic nephropathy. Therefore, there have been some speculations that HyU treatment could stop the progression of CRF modifying the natural history of the diseases. So there will be new clinical trials with old and new medication and metabolic procedure to maintain a very low blood levels in the unknown uremic toxin know as uric acid which seems to be the toxin to the damage kidney. © 2018 S. Karger AG, Basel.

  12. Modification of bacterial cell survival by postirradiation hypoxia

    Vexler, F B; Eidus, L Kh

    1986-01-27

    It is shown that postirradiation hypoxia affects the survival of E.coli. Hypoxic conditions immediately after a single-dose irradiation diminish cell survival in nutrient medium. Increasing time intervals between irradiation and hypoxia decrease the efficiency of the latter, while 1 h after irradiation hypoxia does not modify the survival of irradiated cells. These findings reveal that the mechanisms of action of postirradiation hypoxia on eu- and prokaryotic cells are similar.

  13. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    Araú jo, Paula A.; Miller, Daniel J.; Correia, Patrí cia B.; van Loosdrecht, Mark C.M.; Kruithof, Joop C.; Freeman, Benny Dean; Paul, Donald; Vrouwenvelder, Johannes S.

    2012-01-01

    surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g

  14. Permit application modifications

    NONE

    1995-11-01

    This document contains the Permit Application Modifications for the Y-12 Industrial Landfill V site on the Oak Ridge Reservation. These modifications include the assessment of stability of the proposed Landfill V under static and loading conditions. Analyses performed include the general slope stability, veneer stability of the bottom liner and cover system, and a liquefaction potential assessment of the foundation soils.

  15. The management of modifications

    Bernard, C.

    1992-01-01

    Description of the management methods of modifications at EDF. To maintain safety standards of the nuclear power station the 'Direction de l'Equipment' and the 'Direction du Parc en Exploitation' have jointly fixed the modalities of management for all modifications and recorded them in a 'Practical Guide'

  16. Permit application modifications

    1995-11-01

    This document contains the Permit Application Modifications for the Y-12 Industrial Landfill V site on the Oak Ridge Reservation. These modifications include the assessment of stability of the proposed Landfill V under static and loading conditions. Analyses performed include the general slope stability, veneer stability of the bottom liner and cover system, and a liquefaction potential assessment of the foundation soils

  17. Endocarditis in adults with bacterial meningitis.

    Lucas, Marjolein J; Brouwer, Matthijs C; van der Ende, Arie; van de Beek, Diederik

    2013-05-21

    Endocarditis may precede or complicate bacterial meningitis, but the incidence and impact of endocarditis in bacterial meningitis are unknown. We assessed the incidence and clinical characteristics of patients with meningitis and endocarditis from a nationwide cohort study of adults with community-acquired bacterial meningitis in the Netherlands from 2006 to 2012. Endocarditis was identified in 24 of 1025 episodes (2%) of bacterial meningitis. Cultures yielded Streptococcus pneumoniae in 13 patients, Staphylococcus aureus in 8 patients, and Streptococcus agalactiae, Streptococcus pyogenes, and Streptococcus salivarius in 1 patient each. Clues leading to the diagnosis of endocarditis were cardiac murmurs, persistent or recurrent fever, a history of heart valve disease, and S aureus as the causative pathogen of bacterial meningitis. Treatment consisted of prolonged antibiotic therapy in all patients and surgical valve replacement in 10 patients (42%). Two patients were treated with oral anticoagulants, and both developed life-threatening intracerebral hemorrhage. Systemic (70%) and neurological (54%) complications occurred frequently, leading to a high proportion of patients with unfavorable outcome (63%). Seven of 24 patients (29%) with meningitis and endocarditis died. Endocarditis is an uncommon coexisting condition in bacterial meningitis but is associated with a high rate of unfavorable outcome.

  18. Bioremoval of heavy metals by bacterial biomass.

    Aryal, Mahendra; Liakopoulou-Kyriakides, Maria

    2015-01-01

    Heavy metals are among the most common pollutants found in the environment. Health problems due to the heavy metal pollution become a major concern throughout the world, and therefore, various treatment technologies such as reverse osmosis, ion exchange, solvent extraction, chemical precipitation, and adsorption are adopted to reduce or eliminate their concentration in the environment. Biosorption is a cost-effective and environmental friendly technique, and it can be used for detoxification of heavy metals in industrial effluents as an alternative treatment technology. Biosorption characteristics of various bacterial species are reviewed here with respect to the results reported so far. The role of physical, chemical, and biological modification of bacterial cells for heavy metal removal is presented. The paper evaluates the different kinetic, equilibrium, and thermodynamic models used in bacterial sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions and regeneration of biomass are also discussed.

  19. Modifications to POISSON

    Harwood, L.H.

    1981-01-01

    At MSU we have used the POISSON family of programs extensively for magnetic field calculations. In the presently super-saturated computer situation, reducing the run time for the program is imperative. Thus, a series of modifications have been made to POISSON to speed up convergence. Two of the modifications aim at having the first guess solution as close as possible to the final solution. The other two aim at increasing the convergence rate. In this discussion, a working knowledge of POISSON is assumed. The amount of new code and expected time saving for each modification is discussed

  20. Accommodating for plant modifications

    Weirich, P.H.

    1977-01-01

    Modification to a nuclear power plant may have different causes: 1) new instructions by the authorities; 2) changes of the marginal conditions on the construction site; 3) progress in the technological development. - Examples from different plants are supposed to demonstrate how such changes influence the planning or the construction and how they are integrated in the process of preparation. A distinction can be made between modifications before the completion of the submission of the order, during the phase of preparatory planning and during the construction phase. Of great importance are especially modifications made after the beginning of the construction works, since, in general, there is little scope for technical modifications and since consequences for the time schedule are to be expected. (orig.) [de

  1. Structural dynamic modification

    and stiffness matrices) andaor modal parameters, in order to acquire some ... For the above reasons, another modification approach is presented here ... The data necessary to solve the direct problem are dynamic behaviour of the original.

  2. Pragmatic Graph Rewriting Modifications

    Rodgers, Peter; Vidal, Natalia

    1999-01-01

    We present new pragmatic constructs for easing programming in visual graph rewriting programming languages. The first is a modification to the rewriting process for nodes the host graph, where nodes specified as 'Once Only' in the LHS of a rewrite match at most once with a corresponding node in the host graph. This reduces the previously common use of tags to indicate the progress of matching in the graph. The second modification controls the application of LHS graphs, where those specified a...

  3. Modification of JRR-2

    Miyasaka, Yasuhiko

    1978-01-01

    This report gives an outline of some of the main modifications carried out around the Reactor Core on the Research Reactor JRR-2, at the Tokai Research Establishment of JAERI. The JRR-2 was shut down in December 1973, to improve it in heavy water leakage from the metal packing between core tank and support ring, corrosion of the lower shielding plug, and fault in the control-rod mechanism. Main modifications were a standing seal weld at the support ring to stop heavy water leakage, replacement of the reactor top shield and improvement of the helium system. The control-rod assemblies and the refueling devices were replaced by the newly designed ones also. In addition to the modification plan, the irradiated air exhaust system was improved to reduce radioactive argon gas release through the stack. Works were completed successfully in September 1975. But a light water leakage occurred at the stand pipe below the light water tank on November 11, 1975, which was repaired in about 4 months. When considering the operation of above 5,000 hours after the modification, however, the quality of the modification work may be said to be quite satisfactory. The present report in which works to the completion are described may be valuable as a record of reactor modification which is a new experience at JAERI. (auth.)

  4. Determination of the origin of unknown irradiated nuclear fuel.

    Nicolaou, G

    2006-01-01

    An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' material with U, Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. Then, the 'unknown' fuel has the same origin as the commercial fuel with which it exhibits the highest similarity in U, Pu compositions.

  5. Determination of the origin of unknown irradiated nuclear fuel

    Nicolaou, G.

    2006-01-01

    An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' material with U, Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. Then, the 'unknown' fuel has the same origin as the commercial fuel with which it exhibits the highest similarity in U, Pu compositions

  6. Human Rights and Behavior Modification

    Roos, Philip

    1974-01-01

    Criticisms of behavior modification, which charge that it violates ethical and legal principles, are discussed and reasons are presented to explain behavior modification's susceptibility to attack. (GW)

  7. Acute Bacterial Prostatitis: Diagnosis and Management.

    Coker, Timothy J; Dierfeldt, Daniel M

    2016-01-15

    Acute bacterial prostatitis is an acute infection of the prostate gland that causes pelvic pain and urinary tract symptoms, such as dysuria, urinary frequency, and urinary retention, and may lead to systemic symptoms, such as fevers, chills, nausea, emesis, and malaise. Although the true incidence is unknown, acute bacterial prostatitis is estimated to comprise approximately 10% of all cases of prostatitis. Most acute bacterial prostatitis infections are community acquired, but some occur after transurethral manipulation procedures, such as urethral catheterization and cystoscopy, or after transrectal prostate biopsy. The physical examination should include abdominal, genital, and digital rectal examination to assess for a tender, enlarged, or boggy prostate. Diagnosis is predominantly made based on history and physical examination, but may be aided by urinalysis. Urine cultures should be obtained in all patients who are suspected of having acute bacterial prostatitis to determine the responsible bacteria and its antibiotic sensitivity pattern. Additional laboratory studies can be obtained based on risk factors and severity of illness. Radiography is typically unnecessary. Most patients can be treated as outpatients with oral antibiotics and supportive measures. Hospitalization and broad-spectrum intravenous antibiotics should be considered in patients who are systemically ill, unable to voluntarily urinate, unable to tolerate oral intake, or have risk factors for antibiotic resistance. Typical antibiotic regimens include ceftriaxone and doxycycline, ciprofloxacin, and piperacillin/tazobactam. The risk of nosocomial bacterial prostatitis can be reduced by using antibiotics, such as ciprofloxacin, before transrectal prostate biopsy.

  8. Bacterial lung abscess

    Groskin, S.A.; Panicek, D.M.; Ewing, D.K.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    A retrospective review of patients with bacterial lung abscess was carried out. Demographic, clinical, and radiographical features of this patient group are compared with similar data from patients with empyema and/or cavitated lung carcinoma; differential diagnostic points are stressed. The entity of radiographically occult lung abscess is discussed. Complications associated with bacterial lung abscess are discussed. Current therapeutic options and treatment philosophy for patients with bacterial lung abscess are noted

  9. Peritonitis - spontaneous bacterial

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  10. Antibiotics promote aggregation within aquatic bacterial communities

    Gianluca eCorno

    2014-07-01

    Full Text Available The release of antibiotics (AB into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and productivity. New approaches are required to study the response of microbial communities rather than individual resistance genes. In this study a chemostat-based experiment with 4 coexisting bacterial strains has been performed to mimicking the response of a freshwater bacterial community to the presence of antibiotics in low and high doses. Bacterial abundance rapidly decreased by 75% in the presence of AB, independently of their concentration, and remained constant until the end of the experiment. The bacterial community was mainly dominated by Aeromonas hydrophila and Brevundimonas intermedia while the other two strains, Micrococcus luteus and Rhodococcus sp. never exceed 10%. Interestingly, the bacterial strains, which were isolated at the end of the experiment, were not AB-resistant, while reassembled communities composed of the 4 strains, isolated from treatments under AB stress, significantly raised their performance (growth rate, abundance in the presence of AB compared to the communities reassembled with strains isolated from the treatment without AB. By investigating the phenotypic adaptations of the communities subjected to the different treatments, we found that the presence of AB significantly increased co-aggregation by 5-6 fold.These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of

  11. Unique vaginal microbiota that includes an unknown Mycoplasma-like organism is associated with Trichomonas vaginalis infection.

    Martin, David H; Zozaya, Marcela; Lillis, Rebecca A; Myers, Leann; Nsuami, M Jacques; Ferris, Michael J

    2013-06-15

    The prevalence of Trichomonas vaginalis infection is highest in women with intermediate Nugent scores. We hypothesized that the vaginal microbiota in T. vaginalis-infected women differs from that in T. vaginalis-uninfected women. Vaginal samples from 30 T. vaginalis-infected women were matched by Nugent score to those from 30 T. vaginalis-uninfected women. Equal numbers of women with Nugent scores categorized as normal, intermediate, and bacterial vaginosis were included. The vaginal microbiota was assessed using 454 pyrosequencing analysis of polymerase chain reaction-amplified 16S ribosomal RNA gene sequences. The 16S ribosomal RNA gene sequence of an unknown organism was obtained by universal bacterial polymerase chain reaction amplification, cloning, and sequencing. Principal coordinates analysis of the pyrosequencing data showed divergence of the vaginal microbiota in T. vaginalis-infected and T. vaginalis-uninfected patients among women with normal and those with intermediate Nugent scores but not among women with bacterial vaginosis. Cluster analysis revealed 2 unique groups of T. vaginalis-infected women. One had high abundance of Mycoplasma hominis and other had high abundance of an unknown Mycoplasma species. Women in the former group had clinical evidence of enhanced vaginal inflammation. T. vaginalis may alter the vaginal microbiota in a manner that is favorable to its survival and/or transmissibility. An unknown Mycoplasma species plays a role in some of these transformations. In other cases, these changes may result in a heightened host inflammatory response.

  12. Psychological profile: the problem of modeling the unknown criminal personality

    Г. М. Гетьман

    2013-10-01

    Full Text Available The article investigates the problem of modeling an unknown person in the preparation of criminal psychological profile. Some approaches to the concept of "psychological profile" and "psychological portrait", in particular the proposed delineation of these terms. We consider the system steps in the development of the psychological profile of an unknown perpetrator.

  13. Molecular Analysis of Bacterial Microbiota on Brazilian Currency Note Surfaces

    Tairacan Augusto Pereira da Fonseca

    2015-10-01

    Full Text Available Currency notes have been implicated as a vehicle for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial population residing on banknotes is still unknown in Brazil. In this study, we aimed to investigate the overall bacterial population from 150 different Brazilian Rial (R$ notes in circulation using a culture-independent Illumina massively parallel sequencing approach of the 16S rRNA genes. Samples were randomly collected from three different street markets or “feiras” in the metropolitan region of São Paulo. Taxonomical composition revealed the abundance of Proteobacteria phyla, followed by Firmicutes and Streptophyta, with a total of 1193 bacterial families and 3310 bacterial genera. Most of these bacterial genera are of human, animal, and environmental origins. Also, our analysis revealed the presence of some potential pathogenic bacterial genera including Salmonella, Staphylococcus, and Klebsiella. The results demonstrate that there is a tremendous diversity of bacterial contamination on currency notes, including organisms known to be opportunistic pathogens. One of the factors that may contribute to the richness of bacterial diversity in currency notes is personal hygiene. Thus, our results underscore the need to increase public awareness of the importance of personal hygiene of money handlers who also handle food.

  14. Molecular Analysis of Bacterial Microbiota on Brazilian Currency Note Surfaces.

    Pereira da Fonseca, Tairacan Augusto; Pessôa, Rodrigo; Sanabani, Sabri Saeed

    2015-10-22

    Currency notes have been implicated as a vehicle for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial population residing on banknotes is still unknown in Brazil. In this study, we aimed to investigate the overall bacterial population from 150 different Brazilian Rial (R$) notes in circulation using a culture-independent Illumina massively parallel sequencing approach of the 16S rRNA genes. Samples were randomly collected from three different street markets or "feiras" in the metropolitan region of São Paulo. Taxonomical composition revealed the abundance of Proteobacteria phyla, followed by Firmicutes and Streptophyta, with a total of 1193 bacterial families and 3310 bacterial genera. Most of these bacterial genera are of human, animal, and environmental origins. Also, our analysis revealed the presence of some potential pathogenic bacterial genera including Salmonella, Staphylococcus, and Klebsiella. The results demonstrate that there is a tremendous diversity of bacterial contamination on currency notes, including organisms known to be opportunistic pathogens. One of the factors that may contribute to the richness of bacterial diversity in currency notes is personal hygiene. Thus, our results underscore the need to increase public awareness of the importance of personal hygiene of money handlers who also handle food.

  15. Prevention of bacterial adhesion

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    . As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  16. Some quantitative data on bacterial attachment to pyrite

    Florian, B.; Noël, N.; Thyssen, C.; Felschau, I.; Sand, W.

    2011-01-01

    Bacterial attachment and biofilm formation are important for microbial bioleaching of metal sulfides, however, many details of the role played by bacteria are still unknown. Attachment as the first step in biofilm formation is critical. Our investigations are focused on these processes to control

  17. Robust Fault Detection for Switched Fuzzy Systems With Unknown Input.

    Han, Jian; Zhang, Huaguang; Wang, Yingchun; Sun, Xun

    2017-10-03

    This paper investigates the fault detection problem for a class of switched nonlinear systems in the T-S fuzzy framework. The unknown input is considered in the systems. A novel fault detection unknown input observer design method is proposed. Based on the proposed observer, the unknown input can be removed from the fault detection residual. The weighted H∞ performance level is considered to ensure the robustness. In addition, the weighted H₋ performance level is introduced, which can increase the sensibility of the proposed detection method. To verify the proposed scheme, a numerical simulation example and an electromechanical system simulation example are provided at the end of this paper.

  18. Iterative Selection of Unknown Weights in Direct Weight Optimization Identification

    Xiao Xuan

    2014-01-01

    Full Text Available To the direct weight optimization identification of the nonlinear system, we add some linear terms about input sequences in the former linear affine function so as to approximate the nonlinear property. To choose the two classes of unknown weights in the more linear terms, this paper derives the detailed process on how to choose these unknown weights from theoretical analysis and engineering practice, respectively, and makes sure of their key roles between the unknown weights. From the theoretical analysis, the added unknown weights’ auxiliary role can be known in the whole process of approximating the nonlinear system. From the practical analysis, we learn how to transform one complex optimization problem to its corresponding common quadratic program problem. Then, the common quadratic program problem can be solved by the basic interior point method. Finally, the efficiency and possibility of the proposed strategies can be confirmed by the simulation results.

  19. Carcinoma of Unknown Primary Treatment (PDQ®)—Patient Version

    Carcinoma of unknown primary (CUP), treatment can include surgery, radiation therapy, chemotherapy, or hormone therapy. Get detailed information about the diagnosis and treatment of CUP in this expert-reviewed summary.

  20. RBF neural network based H∞ synchronization for unknown chaotic ...

    , 172 ... the effect of disturbance to an H∞ norm constraint. It is shown that ... unknown chaotic systems; linear matrix inequality (LMI); learning law. 1. Introduction .... (9) is RBFNN H∞ synchronized if the synchronization error e(t) satisfies. ∫ ∞.

  1. Classification of Unknown Thermocouple Types Using Similarity Factor Measurement

    Seshu K. DAMARLA

    2011-01-01

    Full Text Available In contrast to classification using PCA method, a new methodology is proposed for type identification of unknown thermocouple. The new methodology is based on calculating the degree of similarity between two multivariate datasets using two types of similarity factors. One similarity factor is based on principle component analysis and the angles between the principle component subspaces while the other is based on the Mahalanobis distance between the datasets. Datasets containing thermo-emfs against given temperature ranges are formed for each type of thermocouple (e.g. J, K, S, T, R, E, B and N type by experimentation are considered as reference datasets. Datasets corresponding to unknown type are captured. Similarity factor between the datasets one of which being the unknown type and the other being each known type are compared. When maximum similarity factor occurs, then the class of unknown type is allocated to that of known type.

  2. End Group Modification

    Jahnsen, Rasmus O; Sandberg-Schaal, Anne; Frimodt-Møller, Niels

    2015-01-01

    Increased incidence of infections with multidrug-resistant bacterial strains warrants an intensive search for novel potential antimicrobial agents. Here, an antimicrobial peptide analogue with a cationic/hydrophobic alternating design displaying only moderate activity against Gram-positive pathog......Increased incidence of infections with multidrug-resistant bacterial strains warrants an intensive search for novel potential antimicrobial agents. Here, an antimicrobial peptide analogue with a cationic/hydrophobic alternating design displaying only moderate activity against Gram......, the most favorable hydrophobic activity-inducing moieties were found to be cyclohexylacetyl and pentafluorophenylacetyl groups, while the presence of a short PEG-like chain had no significant effect on activity. Introduction of cationic moieties conferred no effect or merely a moderate activity...

  3. Detection of Genetic Modification 'ac2' in Potato Foodstuffs

    Petr Kralik

    2009-01-01

    Full Text Available The genetic modification 'ac2' is based on the insertion and expression of ac2 gene, originally found in seeds of amaranth (Amaranthus caudatus, into the genome of potatoes (Solanum tuberosum. The purpose of the present study is to develop a PCR method for the detection of the mentioned genetically modified potatoes in various foodstuffs. The method was used to test twenty different potato-based products; none of them was positive for the genetic modification 'ac2'. The European Union legislation requires labelling of products made of or containing more than 0.9 % of genetically modified organisms. The genetic modification 'ac2' is not allowed on the European Union market. For that reason it is suitable to have detection methods, not only for the approved genetic modifications, but also for the 'unknown' ones, which could still occur in foodstuffs.

  4. Bursting the bubble on bacterial biofilms

    Crusz, Shanika A; Popat, Roman; Rybtke, Morten Theil

    2012-01-01

    The flow cell biofilm system is an important and widely used tool for the in vitro cultivation and evaluation of bacterial biofilms under hydrodynamic conditions of flow. This paper provides an introduction to the background and use of such systems, accompanied by a detailed guide to the assembly...... of the apparatus including the description of new modifications which enhance its performance. As such, this is an essential guide for the novice biofilm researcher as well as providing valuable trouble-shooting techniques for even the most experienced laboratories. The adoption of a common and reliable...... methodology amongst researchers would enable findings to be shared and replicated amongst the biofilm research community, with the overall aim of advancing understanding and management of these complex and widespread bacterial communities....

  5. Postviral Complications: Bacterial Pneumonia.

    Prasso, Jason E; Deng, Jane C

    2017-03-01

    Secondary bacterial pneumonia after viral respiratory infection remains a significant source of morbidity and mortality. Susceptibility is mediated by a variety of viral and bacterial factors, and complex interactions with the host immune system. Prevention and treatment strategies are limited to influenza vaccination and antibiotics/antivirals respectively. Novel approaches to identifying the individuals with influenza who are at increased risk for secondary bacterial pneumonias are urgently needed. Given the threat of further pandemics and the heightened prevalence of these viruses, more research into the immunologic mechanisms of this disease is warranted with the hope of discovering new potential therapies. Published by Elsevier Inc.

  6. Pragmatic application of the precautionary principle to deal with unknown safety challenges

    Frappier, G.; Viktorov, A.

    2011-01-01

    Nuclear power technology has matured over a number of decades to the point where our understanding of the technology under a wide variety of circumstances is quite high. Despite this high degree of maturity, discoveries of new challenges occasionally surface. These may arise from either unusual or unexpected operational conditions or new experimental findings from ongoing research. With the early realization that such discoveries could occur, a conscious effort was made to take precautions against their negative impacts. Principles such as defence-in-depth, designing for high reliability, incorporation of robust safety margins and use of justified conservatisms are key examples of established practices that are embedded in national regulatory regimes of most, if not all countries with nuclear programs. Because of these provisions the safety cases of the current generation of reactors proved to be quite resilient to discoveries of earlier unrecognized challenges. A fundamentally important element in the management of “unknown unknowns” is a healthy research programme. Such a programme is especially necessary as a precondition for understanding potential impacts from changes in operating conditions or implementation of novel design features. A research programme helps minimizing chances of stumbling on “unknown unknowns”, and allows resolution of emerging issues to by virtue of the accumulated understanding and capability to predict challenges to safety. In the few instances when discoveries occurred with recognized negative effects on safety, these spurred changes in operating conditions, maintenance or testing practices, design modifications, as well as required targeted research projects. This paper outlines several CANDU-specific “discoveries” in the field of thermalhydraulics, illustrating past “unknown unknowns” and the actions taken to address those. The main message, however, is to point out that both the industry and the regulator should

  7. Pragmatic application of the precautionary principle to deal with unknown safety challenges

    Frappier, G.; Viktorov, A., E-mail: gerry.frappier@cnsc-ccsn.gc.ca, E-mail: alex.viktorov@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, Ontario (Canada)

    2011-07-01

    Nuclear power technology has matured over a number of decades to the point where our understanding of the technology under a wide variety of circumstances is quite high. Despite this high degree of maturity, discoveries of new challenges occasionally surface. These may arise from either unusual or unexpected operational conditions or new experimental findings from ongoing research. With the early realization that such discoveries could occur, a conscious effort was made to take precautions against their negative impacts. Principles such as defence-in-depth, designing for high reliability, incorporation of robust safety margins and use of justified conservatisms are key examples of established practices that are embedded in national regulatory regimes of most, if not all countries with nuclear programs. Because of these provisions the safety cases of the current generation of reactors proved to be quite resilient to discoveries of earlier unrecognized challenges. A fundamentally important element in the management of “unknown unknowns” is a healthy research programme. Such a programme is especially necessary as a precondition for understanding potential impacts from changes in operating conditions or implementation of novel design features. A research programme helps minimizing chances of stumbling on “unknown unknowns”, and allows resolution of emerging issues to by virtue of the accumulated understanding and capability to predict challenges to safety. In the few instances when discoveries occurred with recognized negative effects on safety, these spurred changes in operating conditions, maintenance or testing practices, design modifications, as well as required targeted research projects. This paper outlines several CANDU-specific “discoveries” in the field of thermalhydraulics, illustrating past “unknown unknowns” and the actions taken to address those. The main message, however, is to point out that both the industry and the regulator should

  8. An Evidence-Based Review Literature About Risk Indicators and Management of Unknown-Origin Xerostomia

    Farzaneh Agha-hosseini

    2013-01-01

    Full Text Available Objective: This evidence-based article reviews risk indicators and management of unknown-origin xerostomia. Xerostomia and hyposalivation refer to different aspects of dry mouth. Xerostomia is a subjective sensation of dry mouth, whilst hyposalivation is defined as an objective assessment of reduced salivary flow rate. About 30% of the elderly (65 years and older experience xerostomia and hyposalivation. Structural and functional factors, or both may lead to salivary gland dysfunction.Study Selection: The EBM literature search was conducted by using the medical literature database MEDLINE via PubMed and OvidMedline search engines. Results were limited to English language articles (1965 to present including clinical trials (CT, randomized controlled trials (RCT, systematic reviews and review articles. Case control or cohort studies were included for the etiology.Results: Neuropathic etiology such as localized oral alteration of thermal sensations, saliva composition change (for example higher levels of K, Cl, Ca, IgA, amylase, calcium, PTH and cortisol, lower levels of estrogen and progesterone, smaller salivary gland size, and illnesses such as lichen planus, are risk indicators for unknown-origin xerostomia. The management is palliative and preventative. Management of symptoms includes drug administration (systemic secretogogues, saliva substitutes and bile secretion-stimulator, night guard, diet and habit modifications. Other managements may be indicated to treat adverse effects.Conclusion: Neuropathic etiology, saliva composition change, smaller salivary gland size, and illnesses such as oral lichen planus can be suggestive causes for unknown-origin xerostomia. However, longitudinal studies will be important to elucidate the causes of unknown-origin xerostomia.

  9. Enzymatic modification of starch

    Jensen, Susanne Langgård

    In the food industry approaches for using bioengineering are investigated as alternatives to conventional chemical and physical starch modification techniques in development of starches with specific properties. Enzyme-assisted post-harvest modification is an interesting approach to this, since...... it is considered a clean and energy saving technology. This thesis aimed to investigate the effect of using reaction conditions, simulating an industrial process, for enzymatic treatment of starch with branching enzyme (BE) from Rhodothermus obamensis. Thus treatements were conducted at 70°C using very high...... substrate concentration (30-40% dry matter (DM)) and high enzyme activity (750-2250 BE units (BEU)/g sample). Starches from various botanical sources, representing a broad range of properties, were used as substrates. The effects of the used conditions on the BE-reaction were evaluated by characterization...

  10. Bacterial vaginosis - aftercare

    Bacterial vaginosis (BV) is a type of vaginal infection. The vagina normally contains both healthy bacteria and unhealthy bacteria. BV occurs when more unhealthy bacteria grow than healthy bacteria. No one knows ...

  11. Bacterial surface adaptation

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  12. Bacterial intermediate filaments

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  13. Diagnosis of bacterial infection

    direct or indirect evidence of a compatible bacterial pathogen. Inflammation may be .... cardinal features (fever, confusion, headache and neck stiffness). .... specificity, inappropriate indications or poor sampling technique may diminish this ...

  14. Geometrically Consistent Mesh Modification

    Bonito, A.

    2010-01-01

    A new paradigm of adaptivity is to execute refinement, coarsening, and smoothing of meshes on manifolds with incomplete information about their geometry and yet preserve position and curvature accuracy. We refer to this collectively as geometrically consistent (GC) mesh modification. We discuss the concept of discrete GC, show the failure of naive approaches, and propose and analyze a simple algorithm that is GC and accuracy preserving. © 2010 Society for Industrial and Applied Mathematics.

  15. Radiation modification of materials

    Pikaev, A.K.

    1987-01-01

    Industrial and radiation chemical processes of material modification based on cross-linking of polymers as a result of radiation are considered. Among them are production of cables and rods with irradiated modified insulation, production of hardened and thermo-shrinkaging polymer products (films, tubes, fashioned products), production of radiation cross-linked polyethylene foam, technology of radiation vulcanization of elastomers. Attention is paid to radiation plants on the basis of γ-sources and electron acceleratos as well as to radiation conditions

  16. A case of hemophagocytic lymphohistiocytosis presenting as pyrexia of unknown origin

    Indira Madhavan

    2015-01-01

    Full Text Available Hemophagocytic lymphohistiocytosis (HLH is a potentially fatal hyper inflammatory condition, which occurs as either primary (genetic or secondary (acquired due to impaired or absent function of natural killer cells and cytotoxic cells. Common secondary causes include viral and bacterial infections, autoimmune diseases, and hematological malignancies. Extensive phagocytosis of blood cells by histiocytes in bone marrow, spleen, liver and lymphnodes result in peripheral blood cytopenias, hepatosplenomegaly, and lymphadenopathy. We evaluated a case of pyrexia of unknown origin and found out that he fulfilled the criteria for diagnosing HLH. He was started on immunochemotherapy with etoposide, cyclosporine and steroids, but he succumbed to illness within 2 weeks of treatment. High index of suspicion is needed to diagnose HLH and prompt treatment on diagnosis can be lifesaving.

  17. MoCha: Molecular Characterization of Unknown Pathways.

    Lobo, Daniel; Hammelman, Jennifer; Levin, Michael

    2016-04-01

    Automated methods for the reverse-engineering of complex regulatory networks are paving the way for the inference of mechanistic comprehensive models directly from experimental data. These novel methods can infer not only the relations and parameters of the known molecules defined in their input datasets, but also unknown components and pathways identified as necessary by the automated algorithms. Identifying the molecular nature of these unknown components is a crucial step for making testable predictions and experimentally validating the models, yet no specific and efficient tools exist to aid in this process. To this end, we present here MoCha (Molecular Characterization), a tool optimized for the search of unknown proteins and their pathways from a given set of known interacting proteins. MoCha uses the comprehensive dataset of protein-protein interactions provided by the STRING database, which currently includes more than a billion interactions from over 2,000 organisms. MoCha is highly optimized, performing typical searches within seconds. We demonstrate the use of MoCha with the characterization of unknown components from reverse-engineered models from the literature. MoCha is useful for working on network models by hand or as a downstream step of a model inference engine workflow and represents a valuable and efficient tool for the characterization of unknown pathways using known data from thousands of organisms. MoCha and its source code are freely available online under the GPLv3 license.

  18. Behavior Modification in the Classroom

    Whitman, Mryon; Whitman, Joan

    1971-01-01

    This article presents the theoretical rationale for behavior modification, principally through its comparison with traditional psychotherapies, and suggests some behavior modification techniques for the classroom management of maladaptive behavior. (Author)

  19. Grasping Unknown Objects in an Early Cognitive Vision System

    Popovic, Mila

    2011-01-01

    Grasping of unknown objects presents an important and challenging part of robot manipulation. The growing area of service robotics depends upon the ability of robots to autonomously grasp and manipulate a wide range of objects in everyday environments. Simple, non task-specific grasps of unknown ...... and comparing vision-based grasping methods, and the creation of algorithms for bootstrapping a process of acquiring world understanding for artificial cognitive agents....... presents a system for robotic grasping of unknown objects us- ing stereo vision. Grasps are defined based on contour and surface information provided by the Early Cognitive Vision System, that organizes visual informa- tion into a biologically motivated hierarchical representation. The contributions...... of the thesis are: the extension of the Early Cognitive Vision representation with a new type of feature hierarchy in the texture domain, the definition and evaluation of contour based grasping methods, the definition and evaluation of surface based grasping methods, the definition of a benchmark for testing...

  20. Biomaterials modification by ion beam

    Zhang Tonghe; Yi Zhongzhen; Zhang Xu; Wu Yuguang

    2001-01-01

    Ion beam technology is one of best ways for the modification of biomaterials. The results of ion beam modification of biomaterials are given. The method and results of improved biocompatibility are indicated by ion beam technology. The future development of ion beam modification of biomaterials is discussed

  1. Celiac Disease Presenting as Fever of Unknown Origin

    Megan J. Cooney

    2013-01-01

    Full Text Available Celiac disease (CD is a common autoimmune enteropathy that occurs, in affected individuals, with exposure to gluten in the diet and improves with removal of dietary gluten. Although CD is readily considered in patients with classical presentations of the disease, atypical manifestations may be the only presenting symptoms. We present a case of CD in a 16-year-old female presenting as fever of unknown origin, which has not been reported previously. The postulated mechanism for fever in CD and the importance of clinicians having a low threshold for considering CD in the differential diagnosis of fever of unknown origin and other enigmatic clinical presentations is discussed.

  2. Adaptive Incentive Controls for Stackelberg Games with Unknown Cost Functionals.

    1984-01-01

    APR EZT:: F I AN 73S e OsL:-: UNCLASSI?:-- Q4~.’~- .A.., 6, *~*i i~~*~~*.- U ADAPTIVE INCENTIVE CONTROLS FOR STACKELBERG GAMES WITH UNKNOWN COST...AD-A161 885 ADAPTIVE INCENTIVE CONTROLS FOR STACKELBERG GAMES WITH i/1 UNKNOWN COST FUNCTIONALSCU) ILLINOIS UNIV AT URBANA DECISION AND CONTROL LAB T...ORGANIZATION 6b. OFFICE SYMBOL 7.. NAME OF MONITORING ORGANIZATION CoriaeLcenef~pda~ Joint Services Electronics Program Laboratory, Univ. of Illinois N/A

  3. Scheme for teleportation of unknown states of trapped ion

    Chen Mei-Feng; Ma Song-She

    2008-01-01

    A scheme is presented for teleporting an unknown state in a trapped ion system.The scheme only requires a single laser beam.It allows the trap to be in any state with a few phonons,e.g.a thermal motion.Furthermore,it works in the regime,where the Rabi frequency of the laser is on the order of the trap frequency.Thus,the teleportation speed is greatly increased,which is important for decreasing the decoherence effect.This idea can also be used to teleport an unknown ionic entangled state.

  4. Genetic modification and genetic determinism

    Resnik, David B; Vorhaus, Daniel B

    2006-01-01

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

  5. Bacterial Cell Mechanics.

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  6. Biodegradability of bacterial surfactants.

    Lima, Tânia M S; Procópio, Lorena C; Brandão, Felipe D; Carvalho, André M X; Tótola, Marcos R; Borges, Arnaldo C

    2011-06-01

    This work aimed at evaluating the biodegradability of different bacterial surfactants in liquid medium and in soil microcosms. The biodegradability of biosurfactants by pure and mixed bacterial cultures was evaluated through CO(2) evolution. Three bacterial strains, Acinetobacter baumanni LBBMA ES11, Acinetobacter haemolyticus LBBMA 53 and Pseudomonas sp. LBBMA 101B, used the biosurfactants produced by Bacillus sp. LBBMA 111A (mixed lipopeptide), Bacillus subtilis LBBMA 155 (lipopeptide), Flavobacterium sp. LBBMA 168 (mixture of flavolipids), Dietzia Maris LBBMA 191(glycolipid) and Arthrobacter oxydans LBBMA 201(lipopeptide) as carbon sources in minimal medium. The synthetic surfactant sodium dodecyl sulfate (SDS) was also mineralized by these microorganisms, but at a lower rate. CO(2) emitted by a mixed bacterial culture in soil microcosms with biosurfactants was higher than in the microcosm containing SDS. Biosurfactant mineralization in soil was confirmed by the increase in surface tension of the soil aqueous extracts after incubation with the mixed bacterial culture. It can be concluded that, in terms of biodegradability and environmental security, these compounds are more suitable for applications in remediation technologies in comparison to synthetic surfactants. However, more information is needed on structure of biosurfactants, their interaction with soil and contaminants and scale up and cost for biosurfactant production.

  7. Designing towards the Unknown: Engaging with Material and Aesthetic Uncertainty

    Danielle Wilde

    2017-12-01

    Full Text Available New materials with new capabilities demand new ways of approaching design. Destabilising existing methods is crucial to develop new methods. Yet, radical destabilisation—where outcomes remain unknown long enough that new discoveries become possible—is not easy in technology design where complex interdisciplinary teams with time and resource constraints need to deliver concrete outcomes on schedule. The Poetic Kinaesthetic Interface project (PKI engages with this problematic directly. In PKI we use unfolding processes—informed by participatory, speculative and critical design—in emergent actions, to design towards unknown outcomes, using unknown materials. The impossibility of this task is proving as useful as it is disruptive. At its most potent, it is destabilising expectations, aesthetics and processes. Keeping the researchers, collaborators and participants in a state of unknowing, is opening the research potential to far-ranging possibilities. In this article we unpack the motivations driving the PKI project. We present our mixed-methodology, which entangles textile crafts, design interactions and materiality to shape an embodied enquiry. Our research outcomes are procedural and methodological. PKI brings together diverse human, non-human, known and unknown actors to discover where the emergent assemblages might lead. Our approach is re-invigorating—as it demands re-envisioning of—the design process.

  8. Liability for Unknown Risks: A Law and Economics Perspective

    M.G. Faure (Michael); L.T. Visscher (Louis); F. Weber (Franziska)

    2017-01-01

    textabstractIn the law and economics literature liability is generally regarded as an instrument which provides potential tortfeasors with incentives for optimal care taking. The question, however, arises whether liability can still provide those incentives when risks are unknown. That is the

  9. Fault tolerant control of wind turbines using unknown input observers

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2012-01-01

    This paper presents a scheme for accommodating faults in the rotor and generator speed sensors in a wind turbine. These measured values are important both for the wind turbine controller as well as the supervisory control of the wind turbine. The scheme is based on unknown input observers, which...

  10. Value of Bone marrow Examination in Pyrexia of unknown origin

    A Jha

    2013-10-01

    Full Text Available Background: Pyrexia of unknown origin is a common diagnostic dilemma. Series of diagnostic modalities are required to arrive at diagnosis. Bone marrow examination is one of the common tests implicated in the diagnosis in combination with other diagnostic modalities. Present study has attempted to explore the causes of pyrexia of unknown origin based on bone marrow morphological study. Materials and Methods: In a one year prospective study conducted at Manipal Teaching Hospital, Pokhara, Nepal; bone marrow aspiration and biopsy was performed and evaluated morphologically, in 57 patients fulfilling the criteria of classic pyrexia of unknown origin. Results: In 42% cases; specific diagnosis could be made and hematological neoplasm was the most common finding followed by megaloblastic anemia, hypoplastic anemia and one case each of hemophagocytosis, malaria and tuberculosis. Acute leukemia was the most frequently encountered hematological malignancy followed by multiple myeloma, chronic myeloid leukemia, essential thrombocythemia and myelodysplastic syndrome. Conclusion: Morphological examination of bone marrow has important role in diagnosis of pyrexia of unknown origin. However, yield of diagnosis can be increased if it is combined with other diagnostic modalities including radiological, microbiological and serological tests. DOI: http://dx.doi.org/10.3126/jpn.v3i6.8991 Journal of Pathology of Nepal (2013 Vol. 3, 447-451

  11. Fast grasping of unknown objects using principal component analysis

    Lei, Qujiang; Chen, Guangming; Wisse, Martijn

    2017-09-01

    Fast grasping of unknown objects has crucial impact on the efficiency of robot manipulation especially subjected to unfamiliar environments. In order to accelerate grasping speed of unknown objects, principal component analysis is utilized to direct the grasping process. In particular, a single-view partial point cloud is constructed and grasp candidates are allocated along the principal axis. Force balance optimization is employed to analyze possible graspable areas. The obtained graspable area with the minimal resultant force is the best zone for the final grasping execution. It is shown that an unknown object can be more quickly grasped provided that the component analysis principle axis is determined using single-view partial point cloud. To cope with the grasp uncertainty, robot motion is assisted to obtain a new viewpoint. Virtual exploration and experimental tests are carried out to verify this fast gasping algorithm. Both simulation and experimental tests demonstrated excellent performances based on the results of grasping a series of unknown objects. To minimize the grasping uncertainty, the merits of the robot hardware with two 3D cameras can be utilized to suffice the partial point cloud. As a result of utilizing the robot hardware, the grasping reliance is highly enhanced. Therefore, this research demonstrates practical significance for increasing grasping speed and thus increasing robot efficiency under unpredictable environments.

  12. A Size Exclusion Chromatography Laboratory with Unknowns for Introductory Students

    McIntee, Edward J.; Graham, Kate J.; Colosky, Edward C.; Jakubowski, Henry V.

    2015-01-01

    Size exclusion chromatography is an important technique in the separation of biological and polymeric samples by molecular weight. While a number of laboratory experiments have been published that use this technique for the purification of large molecules, this is the first report of an experiment that focuses on purifying an unknown small…

  13. Stochastic Online Learning in Dynamic Networks under Unknown Models

    2016-08-02

    The key is to develop online learning strategies at each individual node. Specifically, through local information exchange with its neighbors, each...infinitely repeated game with incomplete information and developed a dynamic pricing strategy referred to as Competitive and Cooperative Demand Learning...Stochastic Online Learning in Dynamic Networks under Unknown Models This research aims to develop fundamental theories and practical algorithms for

  14. Multiple analysis of an unknown optical multilayer coating

    Dobrowolski, J.A.; Ho, F.C.; Waldorf, A.

    1985-01-01

    Results are given of the analysis at five different laboratories of an unknown optical multilayer coating. In all, eleven different analytical and laboratory techniques were applied to the problem. The multilayer nominally consisted of three dielectric and two metallic layers. It was demonstrated convincingly that with present day techniques it is possible to determine the basic structure of such a coating

  15. Inventory control in case of unknown demand and control parameters

    Janssen, E.

    2010-01-01

    This thesis deals with unknown demand and control parameters in inventory control. Inventory control involves decisions on what to order when and in what quantity. These decisions are based on information about the demand. Models are constructed using complete demand information; these models ensure

  16. Editoria: EBOLA: Fear of the unknown | Comoro | Tanzania Journal ...

    Tanzania Journal of Health Research. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 2 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Editoria: EBOLA: Fear of the unknown. C. Comoro, J.

  17. Lod score curves for phase-unknown matings.

    Hulbert-Shearon, T; Boehnke, M; Lange, K

    1996-01-01

    For a phase-unknown nuclear family, we show that the likelihood and lod score are unimodal, and we describe conditions under which the maximum occurs at recombination fraction theta = 0, theta = 1/2, and 0 < theta < 1/2. These simply stated necessary and sufficient conditions seem to have escaped the notice of previous statistical geneticists.

  18. Teleportation of Unknown Superpositions of Collective Atomic Coherent States

    ZHENG ShiBiao

    2001-01-01

    We propose a scheme to teleport an unknown superposition of two atomic coherent states with different phases. Our scheme is based on resonant and dispersive atom-field interaction. Our scheme provides a possibility of teleporting macroscopic superposition states of many atoms first time.``

  19. Teleportation of an Unknown Atomic State via Adiabatic Passage

    2007-01-01

    We propose a scheme for teleporting an unknown atomic state via adiabatic passage. Taking advantage of adiabatic passage, the atom has no probability of being excited and thus the atomic spontaneous emission is suppressed.We also show that the fidelity can reach 1 under certain condition.

  20. Clostridium difficile: A healthcare-associated infection of unknown ...

    Clostridium difficile: A healthcare-associated infection of unknown significance in adults in sub-Saharan Africa. ... Abstract. Background: Clostridium difficile infection (CDI) causes a high burden of disease in high-resource healthcare systems, with significant morbidity, mortality, and financial implications. CDI is a ...

  1. Severe scratcher-reaction: an unknown health hazard?

    Carsten Sauer Mikkelsen

    2015-03-01

    Full Text Available Tattoos are well known to cause skin problems and the number of reported adverse reactions after tattooing has increased. Illegally imported tattoo ink is unrestrained and can contain unknown ingredients and contamination thereby posing a serious health hazard. We present a case illustrating the risk of pronounced phototoxic allergic reaction and other severe complications after using home kit tattoo ink.

  2. Vision-based autonomous grasping of unknown piled objects

    Johnson, R.K.

    1994-01-01

    Computer vision techniques have been used to develop a vision-based grasping capability for autonomously picking and placing unknown piled objects. This work is currently being applied to the problem of hazardous waste sorting in support of the Department of Energy's Mixed Waste Operations Program

  3. Metastatic Carcinoma of Unknown Primary Presenting as Jugular Venous Thrombosis

    Prince Cheriyan Modayil

    2009-01-01

    Full Text Available Jugular venous thrombosis is unusual and is associated with central venous catheterisation, intravenous drug abuse and head and neck sepsis. It is rarely associated with malignancy. We report a case of metastatic carcinoma of unknown primary in a forty year old female which presented with jugular venous thrombosis. The discussion includes investigation and treatment options for this condition.

  4. Cancer of unknown primitive metastatic. About two clinical cases

    Cawen, L; Cordoba, A.

    2010-01-01

    This work is about the two clinical cases about the unknown primitive metastatic cancer. The main techniques used for the diagnosis, treatment and monitoring of different s carcinomas are: Electronic microscope, molecular biology and genetics, especially histopathological study, topographic survey, ultrasound, radiography, chemotherapy, radiotherapy

  5. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.

  6. Bacterial meningitis in children

    Marji, S.

    2007-01-01

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  7. Bayesian source term determination with unknown covariance of measurements

    Belal, Alkomiet; Tichý, Ondřej; Šmídl, Václav

    2017-04-01

    Determination of a source term of release of a hazardous material into the atmosphere is a very important task for emergency response. We are concerned with the problem of estimation of the source term in the conventional linear inverse problem, y = Mx, where the relationship between the vector of observations y is described using the source-receptor-sensitivity (SRS) matrix M and the unknown source term x. Since the system is typically ill-conditioned, the problem is recast as an optimization problem minR,B(y - Mx)TR-1(y - Mx) + xTB-1x. The first term minimizes the error of the measurements with covariance matrix R, and the second term is a regularization of the source term. There are different types of regularization arising for different choices of matrices R and B, for example, Tikhonov regularization assumes covariance matrix B as the identity matrix multiplied by scalar parameter. In this contribution, we adopt a Bayesian approach to make inference on the unknown source term x as well as unknown R and B. We assume prior on x to be a Gaussian with zero mean and unknown diagonal covariance matrix B. The covariance matrix of the likelihood R is also unknown. We consider two potential choices of the structure of the matrix R. First is the diagonal matrix and the second is a locally correlated structure using information on topology of the measuring network. Since the inference of the model is intractable, iterative variational Bayes algorithm is used for simultaneous estimation of all model parameters. The practical usefulness of our contribution is demonstrated on an application of the resulting algorithm to real data from the European Tracer Experiment (ETEX). This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases by Inverse Atmospheric Dispersion Modelling (STRADI).

  8. Adult bacterial meningitis

    Meyer, C N; Samuelsson, I S; Galle, M

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...

  9. Carbon nanotubes as in vivo bacterial probes

    Bardhan, Neelkanth M.; Ghosh, Debadyuti; Belcher, Angela M.

    2014-09-01

    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F‧-positive and F‧-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F‧-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  10. Carbon nanotubes as in vivo bacterial probes.

    Bardhan, Neelkanth M; Ghosh, Debadyuti; Belcher, Angela M

    2014-09-17

    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F'-positive and F'-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F'-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  11. Bacterial microbiome of lungs in COPD

    Sze MA

    2014-02-01

    Full Text Available Marc A Sze,1 James C Hogg,2 Don D Sin1 1Department of Medicine, 2Department of Pathology and Laboratory Medicine, The James Hogg Research Centre, Providence Heart-Lung Institute, St Paul's Hospital, University of British Columbia, Vancouver, BC, Canada Abstract: Chronic obstructive pulmonary disease (COPD is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease. Keywords: chronic obstructive pulmonary disease, bacterial microbiome, lungs

  12. Enzymatic Modification of Sphingomyelin

    Due to its major role in maintaining the water-retaining properties of the epidermis, ceramide is of great commercial potential in cosmetic and pharmaceuticals such as hair and skin care products. Currently, chemical synthesis of ceramide is a costly process, and developments of alternative cost......-efficient, high yield production methods are of great interest. In the present study, the potential of producing ceramide through the enzymatic hydrolysis of sphingomyelin have been studied. sphingomyelin is a ubiquitous membrane-lipid and rich in dairy products or by-products. It has been verified...... that sphingomyelin modification gives a feasible approach to the potential production of ceramide. The reaction system has been improved through system evaluation and the optimization of several important factors, and phospholipase C from Clostridium perfringens shows higher activity towards the hydrolysis reaction...

  13. [Bacterial biofilms and infection].

    Lasa, I; Del Pozo, J L; Penadés, J R; Leiva, J

    2005-01-01

    In developed countries we tend to think of heart disease and the numerous forms of cancer as the main causes of mortality, but on a global scale infectious diseases come close, or may even be ahead: 14.9 million deaths in 2002 compared to cardiovascular diseases (16.9 million deaths) and cancer (7.1 million deaths) (WHO report 2004). The infectious agents responsible for human mortality have evolved as medical techniques and hygienic measures have changed. Modern-day acute infectious diseases caused by specialized bacterial pathogens such as diphtheria, tetanus, cholera, plague, which represented the main causes of death at the beginning of XX century, have been effectively controlled with antibiotics and vaccines. In their place, more than half of the infectious diseases that affect mildly immunocompromised patients involve bacterial species that are commensal with the human body; these can produce chronic infections, are resistant to antimicrobial agents and there is no effective vaccine against them. Examples of these infections are the otitis media, native valve endocarditis, chronic urinary infections, bacterial prostatitis, osteomyelitis and all the infections related to medical devices. Direct analysis of the surface of medical devices or of tissues that have been foci of chronic infections shows the presence of large numbers of bacteria surrounded by an exopolysaccharide matrix, which has been named the "biofilm". Inside the biofilm, bacteria grow protected from the action of the antibodies, phagocytic cells and antimicrobial treatments. In this article, we describe the role of bacterial biofilms in human persistent infections.

  14. Interfering with bacterial gossip

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation...

  15. Bacterial fingerprints across Europe

    Glasner, Corinna

    2014-01-01

    Bacterial pathogens, such as Staphylococcus aureus and carbapenemase-producing Enterobacteriaceae (CPE), impose major threats to human health worldwide. Both have a ‘Jekyll & Hyde’ character, since they can be present as human commensals, but can also become harmful invasive pathogens especially

  16. Bacterial membrane proteomics.

    Poetsch, Ansgar; Wolters, Dirk

    2008-10-01

    About one quarter to one third of all bacterial genes encode proteins of the inner or outer bacterial membrane. These proteins perform essential physiological functions, such as the import or export of metabolites, the homeostasis of metal ions, the extrusion of toxic substances or antibiotics, and the generation or conversion of energy. The last years have witnessed completion of a plethora of whole-genome sequences of bacteria important for biotechnology or medicine, which is the foundation for proteome and other functional genome analyses. In this review, we discuss the challenges in membrane proteome analysis, starting from sample preparation and leading to MS-data analysis and quantification. The current state of available proteomics technologies as well as their advantages and disadvantages will be described with a focus on shotgun proteomics. Then, we will briefly introduce the most abundant proteins and protein families present in bacterial membranes before bacterial membrane proteomics studies of the last years will be presented. It will be shown how these works enlarged our knowledge about the physiological adaptations that take place in bacteria during fine chemical production, bioremediation, protein overexpression, and during infections. Furthermore, several examples from literature demonstrate the suitability of membrane proteomics for the identification of antigens and different pathogenic strains, as well as the elucidation of membrane protein structure and function.

  17. [Spontaneous bacterial peritonitis].

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  18. Towards high-speed autonomous navigation of unknown environments

    Richter, Charles; Roy, Nicholas

    2015-05-01

    In this paper, we summarize recent research enabling high-speed navigation in unknown environments for dynamic robots that perceive the world through onboard sensors. Many existing solutions to this problem guarantee safety by making the conservative assumption that any unknown portion of the map may contain an obstacle, and therefore constrain planned motions to lie entirely within known free space. In this work, we observe that safety constraints may significantly limit performance and that faster navigation is possible if the planner reasons about collision with unobserved obstacles probabilistically. Our overall approach is to use machine learning to approximate the expected costs of collision using the current state of the map and the planned trajectory. Our contribution is to demonstrate fast but safe planning using a learned function to predict future collision probabilities.

  19. Renal disease masquerading as pyrexia of unknown origin

    D Korivi

    2013-01-01

    Full Text Available Pyrexia of unknown origin is a challenging clinical problem. Infections, malignancies, and connective tissue diseases form the major etiologies for this condition. We report a case of a 57-year-old diabetic male who presented with fever of unknown origin for several months. The course of investigations led to a kidney biopsy which clinched the cause of his fever as well as the underlying diagnosis. The light microscopy findings of expansile storiform fibrosis with a dense inflammatory infiltrate suggested the diagnosis which was confirmed by positive staining of Immunoglobulin G4, the dense lympho-plasmacytic infiltrate and elevated serum IgG4 concentrations. A course of steroids followed by mycophenolate mofetil as maintenance immunosuppression rendered the patient afebrile with improvement of renal function.

  20. Learning Unknown Structure in CRFs via Adaptive Gradient Projection Method

    Wei Xue

    2016-08-01

    Full Text Available We study the problem of fitting probabilistic graphical models to the given data when the structure is not known. More specifically, we focus on learning unknown structure in conditional random fields, especially learning both the structure and parameters of a conditional random field model simultaneously. To do this, we first formulate the learning problem as a convex minimization problem by adding an l_2-regularization to the node parameters and a group l_1-regularization to the edge parameters, and then a gradient-based projection method is proposed to solve it which combines an adaptive stepsize selection strategy with a nonmonotone line search. Extensive simulation experiments are presented to show the performance of our approach in solving unknown structure learning problems.

  1. Quadrotor Control in the Presence of Unknown Mass Properties

    Duivenvoorden, Rikky Ricardo Petrus Rufino

    Quadrotor UAVs are popular due to their mechanical simplicity, as well as their capability to hover and vertically take-off and land. As applications diversify, quadrotors are increasingly required to operate under unknown mass properties, for example as a multirole sensor platform or for package delivery operations. The work presented here consists of the derivation of a generalized quadrotor dynamic model without the typical simplifying assumptions on the first and second moments of mass. The maximum payload capacity of a quadrotor in hover, and the observability of the unknown mass properties are discussed. A brief introduction of L1 adaptive control is provided, and three different L 1 adaptive controllers were designed for the Parrot AR.Drone quadrotor. Their tracking and disturbance rejection performance was compared to the baseline nonlinear controller in experiments. Finally, the results of the combination of L1 adaptive control with iterative learning control are presented, showing high performance trajectory tracking under uncertainty.

  2. Diagnosis of the cancer of unknown primary origin

    Jurisova, S.; Poersoek, S.

    2013-01-01

    Cancer of unknown primary origin (CUP) is one of the ten most frequent cancers worldwide. It constitutes of 3-5% of all human malignancies. At time of diagnosis patients with CUP present with disseminated metastases without established primary origin. CUP manifests as heterogenous group of mainly epithelial cancers recognised by distinct clinico pathological entities. The diagnostic work-up includes extensive histopathology investigations and modern imaging technology. Nevertheless, the primary tumour remains undetected most of the time. (author)

  3. Biomarkers for Ectopic Pregnancy and Pregnancy of Unknown Location

    Senapati, Suneeta; Barnhart, Kurt T.

    2013-01-01

    Early pregnancy failure is the most common complication of pregnancy, and 1–2% of all pregnancies will be ectopic. As one of the leading causes of maternal morbidity and mortality, diagnosing ectopic pregnancy and determining the fate of a pregnancy of unknown location are of great clinical concern. Several serum and plasma biomarkers for ectopic pregnancy have been investigated independently and in combination. The following is a review of the state of biomarker discovery and development for...

  4. Metastatic meningioma presenting as cancer of unknown primary

    Vinay Gupta

    2013-12-01

    Full Text Available We describe a case of anaplastic meningioma presenting in an extracranial osseous location, initially diagnosed as cancer of unknown primary. Although anaplastic meningioma comprise 3% of all meningiomas, this subtype is more likely to be associated with metastases. The increased degree of dedifferentiation in anaplastic meningioma makes diagnosis difficult, especially if characteristic imaging findings of meningioma are not identified. Adequate tissue for diagnostic purposes and appropriate imaging studies may help in establishing a definitive diagnosis.

  5. Transfer of an unknown quantum state, quantum networks, and memory

    Biswas, Asoka; Agarwal, G.S.

    2004-01-01

    We present a protocol for transfer of an unknown quantum state. The protocol is based on a two-mode cavity interacting dispersively in a sequential manner with three-level atoms in the Λ configuration. We propose a scheme for quantum networking using an atomic channel. We investigate the effect of cavity decoherence in the entire process. Further, we demonstrate the possibility of an efficient quantum memory for arbitrary superposition of two modes of a cavity containing one photon

  6. Corticosteroids for Bacterial Keratitis

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Glidden, David V.; Ray, Kathryn J.; Hong, Kevin C.; Oldenburg, Catherine E.; Lee, Salena M.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

    2013-01-01

    Objective To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. Methods Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. Main Outcome Measures The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. Results Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (−0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, −0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, −0.31 to −0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (−0.37 to −0.04; P = .02). Conclusions We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. Application to Clinical Practice Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. PMID:21987582

  7. Characterizing unknown systematics in large scale structure surveys

    Agarwal, Nishant; Ho, Shirley; Myers, Adam D.; Seo, Hee-Jong; Ross, Ashley J.; Bahcall, Neta; Brinkmann, Jonathan; Eisenstein, Daniel J.; Muna, Demitri; Palanque-Delabrouille, Nathalie; Yèche, Christophe; Pâris, Isabelle; Petitjean, Patrick; Schneider, Donald P.; Streblyanska, Alina; Weaver, Benjamin A.

    2014-01-01

    Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data, we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study

  8. Quantum key distribution with an unknown and untrusted source

    Zhao, Yi; Qi, Bing; Lo, Hoi-Kwong

    2009-03-01

    The security of a standard bi-directional ``plug & play'' quantum key distribution (QKD) system has been an open question for a long time. This is mainly because its source is equivalently controlled by an eavesdropper, which means the source is unknown and untrusted. Qualitative discussion on this subject has been made previously. In this paper, we present the first quantitative security analysis on a general class of QKD protocols whose sources are unknown and untrusted. The securities of standard BB84 protocol, weak+vacuum decoy state protocol, and one-decoy decoy state protocol, with unknown and untrusted sources are rigorously proved. We derive rigorous lower bounds to the secure key generation rates of the above three protocols. Our numerical simulation results show that QKD with an untrusted source gives a key generation rate that is close to that with a trusted source. Our work is published in [1]. [4pt] [1] Y. Zhao, B. Qi, and H.-K. Lo, Phys. Rev. A, 77:052327 (2008).

  9. Characterizing unknown systematics in large scale structure surveys

    Agarwal, Nishant; Ho, Shirley [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Seo, Hee-Jong [Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States); Ross, Ashley J. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Bahcall, Neta [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States); Brinkmann, Jonathan [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Eisenstein, Daniel J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Muna, Demitri [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States); Palanque-Delabrouille, Nathalie; Yèche, Christophe [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France); Pâris, Isabelle [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, Patrick [Université Paris 6 et CNRS, Institut d' Astrophysique de Paris, 98bis blvd. Arago, 75014 Paris (France); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Streblyanska, Alina [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Weaver, Benjamin A., E-mail: nishanta@andrew.cmu.edu [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)

    2014-04-01

    Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data, we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study.

  10. Navigation through unknown and dynamic open spaces using topological notions

    Miguel-Tomé, Sergio

    2018-04-01

    Until now, most algorithms used for navigation have had the purpose of directing system towards one point in space. However, humans communicate tasks by specifying spatial relations among elements or places. In addition, the environments in which humans develop their activities are extremely dynamic. The only option that allows for successful navigation in dynamic and unknown environments is making real-time decisions. Therefore, robots capable of collaborating closely with human beings must be able to make decisions based on the local information registered by the sensors and interpret and express spatial relations. Furthermore, when one person is asked to perform a task in an environment, this task is communicated given a category of goals so the person does not need to be supervised. Thus, two problems appear when one wants to create multifunctional robots: how to navigate in dynamic and unknown environments using spatial relations and how to accomplish this without supervision. In this article, a new architecture to address the two cited problems is presented, called the topological qualitative navigation architecture. In previous works, a qualitative heuristic called the heuristic of topological qualitative semantics (HTQS) has been developed to establish and identify spatial relations. However, that heuristic only allows for establishing one spatial relation with a specific object. In contrast, navigation requires a temporal sequence of goals with different objects. The new architecture attains continuous generation of goals and resolves them using HTQS. Thus, the new architecture achieves autonomous navigation in dynamic or unknown open environments.

  11. Comparative Genomics Reveals the Diversity of Restriction-Modification Systems and DNA Methylation Sites in Listeria monocytogenes.

    Chen, Poyin; den Bakker, Henk C; Korlach, Jonas; Kong, Nguyet; Storey, Dylan B; Paxinos, Ellen E; Ashby, Meredith; Clark, Tyson; Luong, Khai; Wiedmann, Martin; Weimer, Bart C

    2017-02-01

    Listeria monocytogenes is a bacterial pathogen that is found in a wide variety of anthropogenic and natural environments. Genome sequencing technologies are rapidly becoming a powerful tool in facilitating our understanding of how genotype, classification phenotypes, and virulence phenotypes interact to predict the health risks of individual bacterial isolates. Currently, 57 closed L. monocytogenes genomes are publicly available, representing three of the four phylogenetic lineages, and they suggest that L. monocytogenes has high genomic synteny. This study contributes an additional 15 closed L. monocytogenes genomes that were used to determine the associations between the genome and methylome with host invasion magnitude. In contrast to previous findings, large chromosomal inversions and rearrangements were detected in five isolates at the chromosome terminus and within rRNA genes, including a previously undescribed inversion within rRNA-encoding regions. Each isolate's epigenome contained highly diverse methyltransferase recognition sites, even within the same serotype and methylation pattern. Eleven strains contained a single chromosomally encoded methyltransferase, one strain contained two methylation systems (one system on a plasmid), and three strains exhibited no methylation, despite the occurrence of methyltransferase genes. In three isolates a new, unknown DNA modification was observed in addition to diverse methylation patterns, accompanied by a novel methylation system. Neither chromosome rearrangement nor strain-specific patterns of epigenome modification observed within virulence genes were correlated with serotype designation, clonal complex, or in vitro infectivity. These data suggest that genome diversity is larger than previously considered in L. monocytogenes and that as more genomes are sequenced, additional structure and methylation novelty will be observed in this organism. Listeria monocytogenes is the causative agent of listeriosis, a disease

  12. Prevalence and Impact of Unknown Diabetes in the ICU.

    Carpenter, David L; Gregg, Sara R; Xu, Kejun; Buchman, Timothy G; Coopersmith, Craig M

    2015-12-01

    Many patients with diabetes and their care providers are unaware of the presence of the disease. Dysglycemia encompassing hyperglycemia, hypoglycemia, and glucose variability is common in the ICU in patients with and without diabetes. The purpose of this study was to determine the impact of unknown diabetes on glycemic control in the ICU. Prospective observational study. Nine ICUs in an academic, tertiary hospital and a hybrid academic/community hospital. Hemoglobin A1c levels were ordered at all ICU admissions from March 1, 2011 to September 30, 2013. Electronic medical records were examined for a history of antihyperglycemic medications or International Classification of Diseases, 9th Edition diagnosis of diabetes. Patients were categorized as having unknown diabetes (hemoglobin A1c > 6.5%, without history of diabetes), no diabetes (hemoglobin A1c 6.5%, with documented history of diabetes). None. A total of 15,737 patients had an hemoglobin A1c and medical record evaluable for the history of diabetes, and 5,635 patients had diabetes diagnosed by either medical history or an elevated hemoglobin A1c in the ICU. Of these, 1,460 patients had unknown diabetes, accounting for 26.0% of all patients with diabetes. This represented 41.0% of patients with an hemoglobin A1c > 6.5% and 9.3% of all ICU patients. Compared with patients without diabetes, patients with unknown diabetes had a higher likelihood of requiring an insulin infusion (44.3% vs 29.3%; p 180 mg/dL; p < 0.0001) and hypoglycemia (8.9% vs 2.5%; blood glucose < 70 mg/dL; p < 0.0001), higher glycemic variability (55.6 vs 28.8, average of patient SD of glucose; p < 0.0001), and increased mortality (13.8% vs 11.4%; p = 0.01). Patients with unknown diabetes represent a significant percentage of ICU admissions. Measurement of hemoglobin A1c at admission can prospectively identify a population that are not known to have diabetes but have significant challenges in glycemic control in the ICU.

  13. Bacterial infec tions in travellers

    namely bacterial causes of travellers' diarrhoea and skin infections, as well as .... Vaccination: protective efficacy against typhoid may be overcome by ingesting a high bacterial load. Vaccine ..... preparation such as cream sauce. Only after ...

  14. Bacterial acquisition in juveniles of several broadcast spawning coral species.

    Koty H Sharp

    Full Text Available Coral animals harbor diverse microorganisms in their tissues, including archaea, bacteria, viruses, and zooxanthellae. The extent to which coral-bacterial associations are specific and the mechanisms for their maintenance across generations in the environment are unknown. The high diversity of bacteria in adult coral colonies has made it challenging to identify species-specific patterns. Localization of bacteria in gametes and larvae of corals presents an opportunity for determining when bacterial-coral associations are initiated and whether they are dynamic throughout early development. This study focuses on the early onset of bacterial associations in the mass spawning corals Montastraea annularis, M. franksi, M. faveolata, Acropora palmata, A. cervicornis, Diploria strigosa, and A. humilis. The presence of bacteria and timing of bacterial colonization was evaluated in gametes, swimming planulae, and newly settled polyps by fluorescence in situ hybridization (FISH using general eubacterial probes and laser-scanning confocal microscopy. The coral species investigated in this study do not appear to transmit bacteria via their gametes, and bacteria are not detectable in or on the corals until after settlement and metamorphosis. This study suggests that mass-spawning corals do not acquire, or are not colonized by, detectable numbers of bacteria until after larval settlement and development of the juvenile polyp. This timing lays the groundwork for developing and testing new hypotheses regarding general regulatory mechanisms that control bacterial colonization and infection of corals, and how interactions among bacteria and juvenile polyps influence the structure of bacterial assemblages in corals.

  15. Bacterial acquisition in juveniles of several broadcast spawning coral species.

    Sharp, Koty H; Ritchie, Kim B; Schupp, Peter J; Ritson-Williams, Raphael; Paul, Valerie J

    2010-05-28

    Coral animals harbor diverse microorganisms in their tissues, including archaea, bacteria, viruses, and zooxanthellae. The extent to which coral-bacterial associations are specific and the mechanisms for their maintenance across generations in the environment are unknown. The high diversity of bacteria in adult coral colonies has made it challenging to identify species-specific patterns. Localization of bacteria in gametes and larvae of corals presents an opportunity for determining when bacterial-coral associations are initiated and whether they are dynamic throughout early development. This study focuses on the early onset of bacterial associations in the mass spawning corals Montastraea annularis, M. franksi, M. faveolata, Acropora palmata, A. cervicornis, Diploria strigosa, and A. humilis. The presence of bacteria and timing of bacterial colonization was evaluated in gametes, swimming planulae, and newly settled polyps by fluorescence in situ hybridization (FISH) using general eubacterial probes and laser-scanning confocal microscopy. The coral species investigated in this study do not appear to transmit bacteria via their gametes, and bacteria are not detectable in or on the corals until after settlement and metamorphosis. This study suggests that mass-spawning corals do not acquire, or are not colonized by, detectable numbers of bacteria until after larval settlement and development of the juvenile polyp. This timing lays the groundwork for developing and testing new hypotheses regarding general regulatory mechanisms that control bacterial colonization and infection of corals, and how interactions among bacteria and juvenile polyps influence the structure of bacterial assemblages in corals.

  16. Metamorphosis of a butterfly-associated bacterial community.

    Hammer, Tobin J; McMillan, W Owen; Fierer, Noah

    2014-01-01

    Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar) and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  17. Metamorphosis of a butterfly-associated bacterial community.

    Tobin J Hammer

    Full Text Available Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  18. TEXTILE SURFACE MODIFICATION BY PYHSICAL VAPOR DEPOSITION – (REVIEW

    YUCE Ismail

    2017-05-01

    Full Text Available Textile products are used in various branches of the industry from automotive to space products. Textiles produced for industrial use are generally referred to as technical textiles. Technical textiles are nowadays applied to several areas including transportation, medicine, agriculture, protection, sports, packaging, civil engineering and industry. There are rapid developments in the types of materials used in technical textiles. Therefore, modification and functionalization of textile surfaces is becoming more crucial. The improvements of the properties such as anti-bacterial properties, fire resistivity, UV radiation resistance, electrical conductivity, self cleaning, and super hydrophobic, is getting more concern with respect to developments in textile engineering. The properties of textile surfaces are closely related to the fiber structure, the differences in the polymer composition, the fiber mixture ratio, and the physical and chemical processes applied. Textile surface modifications can be examined in four groups under the name mechanical, chemical, burning and plasma. Surface modifications are made to improve the functionality of textile products. Textile surface modifications affect the properties of the products such as softness, adhesion and wettability. The purpose of this work is to reveal varieties of vapor deposition modifications to improve functionality. For this purpose, the pyhsical vapor deposition methods, their affects on textile products and their end-uses will be reviewed.

  19. Streptococcus massiliensis in the human mouth: a phylogenetic approach for the inference of bacterial habitats.

    Póntigo, F; Silva, C; Moraga, M; Flores, S V

    2015-12-29

    Streptococcus is a diverse bacterial lineage. Species of this genus occupy a myriad of environments inside humans and other animals. Despite the elucidation of several of these habitats, many remain to be identified. Here, we explore a methodological approach to reveal unknown bacterial environments. Specifically, we inferred the phylogeny of the Mitis group by analyzing the sequences of eight genes. In addition, information regarding habitat use of species belonging to this group was obtained from the scientific literature. The oral cavity emerged as a potential, previously unknown, environment of Streptococcus massiliensis. This phylogeny-based prediction was confirmed by species-specific polymerase chain reaction (PCR) amplification. We propose employing a similar approach, i.e., use of bibliographic data and molecular phylogenetics as predictive methods, and species-specific PCR as confirmation, in order to reveal other unknown habitats in further bacterial taxa.

  20. Structure of bacterial lipopolysaccharides.

    Caroff, Martine; Karibian, Doris

    2003-11-14

    Bacterial lipopolysaccharides are the major components of the outer surface of Gram-negative bacteria They are often of interest in medicine for their immunomodulatory properties. In small amounts they can be beneficial, but in larger amounts they may cause endotoxic shock. Although they share a common architecture, their structural details exert a strong influence on their activity. These molecules comprise: a lipid moiety, called lipid A, which is considered to be the endotoxic component, a glycosidic part consisting of a core of approximately 10 monosaccharides and, in "smooth-type" lipopolysaccharides, a third region, named O-chain, consisting of repetitive subunits of one to eight monosaccharides responsible for much of the immunospecificity of the bacterial cell.

  1. Cooperative Bacterial Foraging Optimization

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  2. Balancing the unknown: Consumer judgment of unfamiliar technologies

    Hagemann, Kit; Scholderer, Joachim

    The aim of the present paper is to explain how consumers form attitudes towards upstream food technologies in the absence of direct experience or in-depth information about the technology and the products resulting from its application. Using Structural Equation Modelling (SEM) we compared three...... food technologies against genetically modification (GM) and found that previously held attitude toward GM influenced attitude toward all three food technologies. The findings suggest that consumers form a set of heuristics that consist of general socio-political attitudes and these heuristics are used...

  3. Estimation of the false discovery proportion with unknown dependence.

    Fan, Jianqing; Han, Xu

    2017-09-01

    Large-scale multiple testing with correlated test statistics arises frequently in many scientific research. Incorporating correlation information in approximating false discovery proportion has attracted increasing attention in recent years. When the covariance matrix of test statistics is known, Fan, Han & Gu (2012) provided an accurate approximation of False Discovery Proportion (FDP) under arbitrary dependence structure and some sparsity assumption. However, the covariance matrix is often unknown in many applications and such dependence information has to be estimated before approximating FDP. The estimation accuracy can greatly affect FDP approximation. In the current paper, we aim to theoretically study the impact of unknown dependence on the testing procedure and establish a general framework such that FDP can be well approximated. The impacts of unknown dependence on approximating FDP are in the following two major aspects: through estimating eigenvalues/eigenvectors and through estimating marginal variances. To address the challenges in these two aspects, we firstly develop general requirements on estimates of eigenvalues and eigenvectors for a good approximation of FDP. We then give conditions on the structures of covariance matrices that satisfy such requirements. Such dependence structures include banded/sparse covariance matrices and (conditional) sparse precision matrices. Within this framework, we also consider a special example to illustrate our method where data are sampled from an approximate factor model, which encompasses most practical situations. We provide a good approximation of FDP via exploiting this specific dependence structure. The results are further generalized to the situation where the multivariate normality assumption is relaxed. Our results are demonstrated by simulation studies and some real data applications.

  4. Neurological autoantibodies in drug-resistant epilepsy of unknown cause.

    Tecellioglu, Mehmet; Kamisli, Ozden; Kamisli, Suat; Yucel, Fatma Ebru; Ozcan, Cemal

    2018-03-09

    Autoimmune epilepsy is a rarely diagnosed condition. Recognition of the underlying autoimmune condition is important, as these patients can be resistant to antiepileptic drugs. To determine the autoimmune and oncological antibodies in adult drug-resistant epilepsy of unknown cause and identify the clinical, radiological, and EEG findings associated with these antibodies according to data in the literature. Eighty-two patients with drug-resistant epilepsy of unknown cause were prospectively identified. Clinical features were recorded. The levels of anti-voltage-gated potassium channel complex (anti-VGKCc), anti-thyroid peroxidase (anti-TPO), anti-nuclear antibody (ANA), anti-glutamic acid decarboxylase (anti-GAD), anti-phospholipid IgG and IgM, anti-cardiolipin IgG and IgM, and onconeural antibodies were determined. Serum antibody positivity suggesting the potential role of autoimmunity in the aetiology was present in 17 patients with resistant epilepsy (22.0%). Multiple antibodies were found in two patients (2.6%). One of these patients (1.3%) had anti-VGKCc and ANA, whereas another (1.3%) had anti-VGKCc and anti-TPO. A single antibody was present in 15 patients (19.5%). Of the 77 patients finally included in the study, 4 had anti-TPO (5.2%), 1 had anti-GAD (1.3%), 4 had anti-VGKCc (5.2%) 8 had ANA (10.3%), and 2 had onconeural antibodies (2.6%) (1 patient had anti-Yo and 1 had anti-MA2/TA). The other antibodies investigated were not detected. EEG abnormality (focal), focal seizure incidence, and frequent seizures were more common in antibody-positive patients. Autoimmune factors may be aetiologically relevant in patients with drug-resistant epilepsy of unknown cause, especially if focal seizures are present together with focal EEG abnormality and frequent seizures.

  5. Bacterial control of cyanobacteria

    Ndlela, Luyanda L

    2017-08-01

    Full Text Available of biological control appears to be direct contact. • Ndlela, L. L. et al. (2016) ‘An overview of cyanobacterial bloom occurrences and research in Africa over the last decade’, Harmful Algae, 60 • Gumbo, J.R. et al. (2010) The Isolation and identification... of Predatory Bacteria from a Microcystis algal Bloom.. African Journal of Biotechnology, 9. *Special acknowledgement goes to the National Research foundation for funding this presentation Bacterial control of cyanobacteria Luyanda...

  6. Optimal unambiguous comparison of two unknown squeezed vacua

    Olivares, Stefano; Paris, Matteo G. A.; Sedlak, Michal; Rapsan, Peter; Busek, Vladimir

    2011-01-01

    We propose a scheme for the unambiguous state comparison (USC) of two unknown squeezed vacuum states of the electromagnetic field. Our setup is based on linear optical elements and photon-number detectors, and it achieves optimal USC in an ideal case of unit quantum efficiency. In realistic conditions, i.e., for nonunit quantum efficiency of photodetectors, we evaluate the probability of getting an ambiguous result as well as the reliability of the scheme, thus showing its robustness in comparison to previous proposals.

  7. Fast entanglement detection for unknown states of two spatial qutrits

    Lima, G.; Gomez, E. S.; Saavedra, C.; Vargas, A.; Vianna, R. O.

    2010-01-01

    We investigate the practicality of the method proposed by Maciel et al. [Phys. Rev. A. 80, 032325 (2009).] for detecting the entanglement of two spatial qutrits (three-dimensional quantum systems), which are encoded in the discrete transverse momentum of single photons transmitted through a multislit aperture. The method is based on the acquisition of partial information of the quantum state through projective measurements, and a data processing analysis done with semidefinite programs. This analysis relies on generating gradually an optimal entanglement witness operator, and numerical investigations have shown that it allows for the entanglement detection of unknown states with a cost much lower than full state tomography.

  8. Algorithms for Rapidly Dispersing Robot Swarms in Unknown Environments

    Hsiang, Tien-Ruey; Arkin, Esther M.; Bender, Michael; Fekete, Sandor P.; Mitchell, Joseph S. B.

    2002-01-01

    We develop and analyze algorithms for dispersing a swarm of primitive robots in an unknown environment, R. The primary objective is to minimize the makespan, that is, the time to fill the entire region. An environment is composed of pixels that form a connected subset of the integer grid. There is at most one robot per pixel and robots move horizontally or vertically at unit speed. Robots enter R by means of k>=1 door pixels Robots are primitive finite automata, only having local communicatio...

  9. Modal Parameter Identification from Responses of General Unknown Random Inputs

    Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

    1996-01-01

    Modal parameter identification from ambient responses due to a general unknown random inputs is investigated. Existing identification techniques which are based on assumptions of white noise and or stationary random inputs are utilized even though the inputs conditions are not satisfied....... This is accomplished via adding. In cascade. A force cascade conversion to the structures system under consideration. The input to the force conversion system is white noise and the output of which is the actual force(s) applied to the structure. The white noise input(s) and the structures responses are then used...

  10. Bacterial growth kinetics

    Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

    1989-01-01

    Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector

  11. Adaptive Bacterial Foraging Optimization

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  12. Genetic modification and genetic determinism

    Vorhaus Daniel B

    2006-06-01

    Full Text Available Abstract In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions.

  13. S1PR3 Signaling Drives Bacterial Killing and Is Required for Survival in Bacterial Sepsis.

    Hou, JinChao; Chen, QiXing; Wu, XiaoLiang; Zhao, DongYan; Reuveni, Hadas; Licht, Tamar; Xu, MengLong; Hu, Hu; Hoeft, Andreas; Ben-Sasson, Shmuel A; Shu, Qiang; Fang, XiangMing

    2017-12-15

    Efficient elimination of pathogenic bacteria is a critical determinant in the outcome of sepsis. Sphingosine-1-phosphate receptor 3 (S1PR3) mediates multiple aspects of the inflammatory response during sepsis, but whether S1PR3 signaling is necessary for eliminating the invading pathogens remains unknown. To investigate the role of S1PR3 in antibacterial immunity during sepsis. Loss- and gain-of-function experiments were performed using cell and murine models. S1PR3 levels were determined in patients with sepsis and healthy volunteers. S1PR3 protein levels were up-regulated in macrophages upon bacterial stimulation. S1pr3 -/- mice showed increased mortality and increased bacterial burden in multiple models of sepsis. The transfer of wild-type bone marrow-derived macrophages rescued S1pr3 -/- mice from lethal sepsis. S1PR3-overexpressing macrophages further ameliorated the mortality rate of sepsis. Loss of S1PR3 led to markedly decreased bacterial killing in macrophages. Enhancing endogenous S1PR3 activity using a peptide agonist potentiated the macrophage bactericidal function and improved survival rates in multiple models of sepsis. Mechanically, the reactive oxygen species levels were decreased and phagosome maturation was delayed in S1pr3 -/- macrophages due to impaired recruitment of vacuolar protein-sorting 34 to the phagosomes. In addition, S1RP3 expression levels were elevated in monocytes from patients with sepsis. Higher levels of monocytic S1PR3 were associated with efficient intracellular bactericidal activity, better immune status, and preferable outcomes. S1PR3 signaling drives bacterial killing and is essential for survival in bacterial sepsis. Interventions targeting S1PR3 signaling could have translational implications for manipulating the innate immune response to combat pathogens.

  14. Group prioritisation with unknown expert weights in incomplete linguistic context

    Cheng, Dong; Cheng, Faxin; Zhou, Zhili; Wang, Juan

    2017-09-01

    In this paper, we study a group prioritisation problem in situations when the expert weights are completely unknown and their judgement preferences are linguistic and incomplete. Starting from the theory of relative entropy (RE) and multiplicative consistency, an optimisation model is provided for deriving an individual priority vector without estimating the missing value(s) of an incomplete linguistic preference relation. In order to address the unknown expert weights in the group aggregating process, we define two new kinds of expert weight indicators based on RE: proximity entropy weight and similarity entropy weight. Furthermore, a dynamic-adjusting algorithm (DAA) is proposed to obtain an objective expert weight vector and capture the dynamic properties involved in it. Unlike the extant literature of group prioritisation, the proposed RE approach does not require pre-allocation of expert weights and can solve incomplete preference relations. An interesting finding is that once all the experts express their preference relations, the final expert weight vector derived from the DAA is fixed irrespective of the initial settings of expert weights. Finally, an application example is conducted to validate the effectiveness and robustness of the RE approach.

  15. Unknown facets of Well-Known Scientists Series - Part II

    V S Dixit

    2016-01-01

    Full Text Available 1st in the series of articles on “Unknown Facets of well-known Scientists” was about Sir Frederick Grant Banting, co-discoverer of Insulin, who also researched in Aviation and Diving Medicines, results of which brought extraordinary benefits for Flight crew during the World War II. The article was published in the previous issue of the Journal Unknown facets could be celebrated attributes, talents or otherwise, but it is necessary that we get to know fully about the “great mind". THIS ARTICLE IS ABOUT DR WERNER THEODOR OTTO FORSSMANN, A CARDIOLOGIST, WHO BECAME A UROLOGIST! Does the name Dr Forssmann ring a bell? He shared the 1956 Nobel Prize in Physiology or Medicine with “Andre Cournand and Dickinson Richards". The trio was awarded for their “discoveries concerning heart catheterization and pathological changes in the circulatory system". Dr Forssmann was nominated for performing an experiment in which he introduced a catheter into a vein of his arm, further passing it onward into his heart It was risky. This was in the year 1929. Subject of this article is the self-experimentation he carried out and what happened later.

  16. Parameter identification of chaos system based on unknown parameter observer

    Wang Shaoming; Luo Haigeng; Yue Chaoyuan; Liao Xiaoxin

    2008-01-01

    Parameter identification of chaos system based on unknown parameter observer is discussed generally. Based on the work of Guan et al. [X.P. Guan, H.P. Peng, L.X. Li, et al., Acta Phys. Sinica 50 (2001) 26], the design of unknown parameter observer is improved. The application of the improved approach is extended greatly. The works in some literatures [X.P. Guan, H.P. Peng, L.X. Li, et al., Acta Phys. Sinica 50 (2001) 26; J.H. Lue, S.C. Zhang, Phys. Lett. A 286 (2001) 148; X.Q. Wu, J.A. Lu, Chaos Solitons Fractals 18 (2003) 721; J. Liu, S.H. Chen, J. Xie, Chaos Solitons Fractals 19 (2004) 533] are only the special cases of our Corollaries 1 and 2. Some observers for Lue system and a new chaos system are designed to test our improved method, and simulations results demonstrate the effectiveness and feasibility of the improved approach

  17. Unknown quantum states: The quantum de Finetti representation

    Caves, Carlton M.; Fuchs, Christopher A.; Schack, Ruediger

    2002-01-01

    We present an elementary proof of the quantum de Finetti representation theorem, a quantum analog of de Finetti's classical theorem on exchangeable probability assignments. This contrasts with the original proof of Hudson and Moody [Z. Wahrschein. verw. Geb. 33, 343 (1976)], which relies on advanced mathematics and does not share the same potential for generalization. The classical de Finetti theorem provides an operational definition of the concept of an unknown probability in Bayesian probability theory, where probabilities are taken to be degrees of belief instead of objective states of nature. The quantum de Finetti theorem, in a closely analogous fashion, deals with exchangeable density-operator assignments and provides an operational definition of the concept of an ''unknown quantum state'' in quantum-state tomography. This result is especially important for information-based interpretations of quantum mechanics, where quantum states, like probabilities, are taken to be states of knowledge rather than states of nature. We further demonstrate that the theorem fails for real Hilbert spaces and discuss the significance of this point

  18. Atmospheric turbulence profiling with unknown power spectral density

    Helin, Tapio; Kindermann, Stefan; Lehtonen, Jonatan; Ramlau, Ronny

    2018-04-01

    Adaptive optics (AO) is a technology in modern ground-based optical telescopes to compensate for the wavefront distortions caused by atmospheric turbulence. One method that allows to retrieve information about the atmosphere from telescope data is so-called SLODAR, where the atmospheric turbulence profile is estimated based on correlation data of Shack-Hartmann wavefront measurements. This approach relies on a layered Kolmogorov turbulence model. In this article, we propose a novel extension of the SLODAR concept by including a general non-Kolmogorov turbulence layer close to the ground with an unknown power spectral density. We prove that the joint estimation problem of the turbulence profile above ground simultaneously with the unknown power spectral density at the ground is ill-posed and propose three numerical reconstruction methods. We demonstrate by numerical simulations that our methods lead to substantial improvements in the turbulence profile reconstruction compared to the standard SLODAR-type approach. Also, our methods can accurately locate local perturbations in non-Kolmogorov power spectral densities.

  19. Three-dimensional cinematography with control object of unknown shape.

    Dapena, J; Harman, E A; Miller, J A

    1982-01-01

    A technique for reconstruction of three-dimensional (3D) motion which involves a simple filming procedure but allows the deduction of coordinates in large object volumes was developed. Internal camera parameters are calculated from measurements of the film images of two calibrated crosses while external camera parameters are calculated from the film images of points in a control object of unknown shape but at least one known length. The control object, which includes the volume in which the activity is to take place, is formed by a series of poles placed at unknown locations, each carrying two targets. From the internal and external camera parameters, and from locations of the images of point in the films of the two cameras, 3D coordinates of the point can be calculated. Root mean square errors of the three coordinates of points in a large object volume (5m x 5m x 1.5m) were 15 mm, 13 mm, 13 mm and 6 mm, and relative errors in lengths averaged 0.5%, 0.7% and 0.5%, respectively.

  20. Reactive Path Planning Approach for Docking Robots in Unknown Environment

    Peng Cui

    2017-01-01

    Full Text Available Autonomous robots need to be recharged and exchange information with the host through docking in the long-distance tasks. Therefore, feasible path is required in the docking process to guide the robot and adjust its pose. However, when there are unknown obstacles in the work area, it becomes difficult to determine the feasible path for docking. This paper presents a reactive path planning approach named Dubins-APF (DAPF to solve the path planning problem for docking in unknown environment with obstacles. In this proposed approach the Dubins curves are combined with the designed obstacle avoidance potential field to plan the feasible path. Firstly, an initial path is planned and followed according to the configurations of the robot and the docking station. Then when the followed path is evaluated to be infeasible, the intermediate configuration is calculated as well as the replanned path based on the obstacle avoidance potential field. The robot will be navigated to the docking station with proper pose eventually via the DAPF approach. The proposed DAPF approach is efficient and does not require the prior knowledge about the environment. Simulation results are given to validate the effectiveness and feasibility of the proposed approach.

  1. Neurological Autoantibody Prevalence in Epilepsy of Unknown Etiology.

    Dubey, Divyanshu; Alqallaf, Abdulradha; Hays, Ryan; Freeman, Matthew; Chen, Kevin; Ding, Kan; Agostini, Mark; Vernino, Steven

    2017-04-01

    Autoimmune epilepsy is an underrecognized condition, and its true incidence is unknown. Identifying patients with an underlying autoimmune origin is critical because these patients' condition may remain refractory to conventional antiseizure medications but may respond to immunotherapy. To determine the prevalence of neurological autoantibodies (Abs) among adult patients with epilepsy of unknown etiology. Consecutive patients presenting to neurology services with new-onset epilepsy or established epilepsy of unknown etiology were identified. Serum samples were tested for autoimmune encephalitis Abs as well as thyroperoxidase (TPO) and glutamic acid decarboxylase 65 (GAD65) Abs. An antibody prevalence in epilepsy (APE) score based on clinical characteristics was assigned prospectively. Data were collected from June 1, 2015, to June 1, 2016. Presence of neurological Abs. A score based on clinical characteristics was assigned to estimate the probability of seropositivity prior to antibody test results. Good seizure outcome was estimated on the basis of significant reduction of seizure frequency at the first follow-up or seizure freedom. Of the 127 patients (68 males and 59 females) enrolled in the study, 15 were subsequently excluded after identification of an alternative diagnosis. Serum Abs suggesting a potential autoimmune etiology were detected in 39 (34.8%) cases. More than 1 Ab was detected in 7 patients (6.3%): 3 (2.7%) had TPO-Ab and voltage-gated potassium channel complex (VGKCc) Ab, 2 (1.8%) had GAD65-Ab and VGKCc-Ab, 1 had TPO-Ab and GAD65-Ab, and 1 had anti-Hu Ab and GAD65-Ab. Thirty-two patients (28.6%) had a single Ab marker. Among 112 patients included in the study, 15 (13.4%) had TPO-Ab, 14 (12.5%) had GAD65-Ab, 12 (10.7%) had VGKCc (4 of whom were positive for leucine-rich glioma-inactivated protein 1 [LGI1] Ab), and 4 (3.6%) had N-methyl-D-aspartate receptor (NMDAR) Ab. Even after excluding TPO-Ab and low-titer GAD65-Ab, Abs strongly suggesting an

  2. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    Kumaran Narayanan

    2011-01-01

    Full Text Available Gene expression from bacterial artificial chromosome (BAC clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented a major obstacle for introducing modifications using conventional genetic engineering strategies. The development of in vivo homologous recombination strategies based on recombineering in E. coli has helped resolve this problem by enabling facile engineering of high molecular weight BAC DNA without dependence on suitably placed restriction enzymes or cloning steps. These techniques have considerably expanded the possibilities for studying functional genetics using BACs in vitro and in vivo.

  3. Radiology of bacterial pneumonia

    Vilar, Jose; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-01-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings

  4. Radiology of bacterial pneumonia

    Vilar, Jose E-mail: vilar_jlu@gva.es; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-08-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

  5. Obstacle Avoidance for Unmanned Undersea Vehicle in Unknown Unstructured Environment

    Zheping Yan

    2013-01-01

    Full Text Available To avoid obstacle in the unknown environment for unmanned undersea vehicle (UUV, an obstacle avoiding system based on improved vector field histogram (VFH is designed. Forward looking sonar is used to detect the environment, and the divisional sonar modal is applied to deal with the measure uncertainty. To adapt to the VFH, rolling occupancy grids are used for the map building, and high accuracy details of local environment are obtained. The threshold is adaptively adjusted by the statistic of obstacles to solve the problem that VFH is sensitive to threshold. To improve the environment adaptability, the hybrid-behaviors strategy is proposed, which selects the optimal avoidance command according to the motion status and environment character. The simulation shows that UUV could avoid the obstacles fast and escape from the U shape obstacles.

  6. Fever of unknown origin (FUO): CMV infectious mononucleosis or lymphoma?

    Cunha, Burke A; Chawla, Karishma

    2018-04-20

    Fever of unknown origin (FUO) refers to fevers of > 101 °F that persist for > 3 weeks and remain undiagnosed after a focused inpatient or outpatient workup. FUO may be due to infectious, malignant/neoplastic, rheumatic/inflammatory, or miscellaneous disorders. The FUO category determines the focus of the diagnostic workup. In the case presented of an FUO in a young woman, there were clinical findings of both CMV infectious mononucleosis or a lymphoma, e.g., highly elevated ESR, elevated ferritin levels, and elevated ACE level, β-2 microglobulins. The indium scan showed intense splenic uptake. Lymph node biopsy, PET scan, and flow cytometry were negative for lymphoma. CMV infectious mononucleosis was the diagnosis, and she made a slow recovery.

  7. Impact of CT in patients with sepsis of unknown origin

    Barkhausen, J.; Stoeblen, F.; Mueller, R.D.

    1999-01-01

    Purpose: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin. Material and Methods: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated. Results: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1). Conclusion: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a spetic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery. (orig.)

  8. Impact of CT in patients with sepsis of unknown origin

    Barkhausen, J.; Stoeblen, F.; Mueller, R.D. [University Hospital Essen (Germany). Dept. of Radiology; Dominguez-Fernandez, E. [University Hospital Essen (Germany). Dept. of General Surgery; Henseke, P. [Nycomed-Amersham Arzneimittel GmbH, Muenchen (Germany)

    1999-09-01

    Purpose: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin. Material and Methods: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated. Results: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1). Conclusion: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a spetic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery. (orig.)

  9. Mobile robot navigation in unknown static environments using ANFIS controller

    Anish Pandey

    2016-09-01

    Full Text Available Navigation and obstacle avoidance are the most important task for any mobile robots. This article presents the Adaptive Neuro-Fuzzy Inference System (ANFIS controller for mobile robot navigation and obstacle avoidance in the unknown static environments. The different sensors such as ultrasonic range finder sensor and sharp infrared range sensor are used to detect the forward obstacles in the environments. The inputs of the ANFIS controller are obstacle distances obtained from the sensors, and the controller output is a robot steering angle. The primary objective of the present work is to use ANFIS controller to guide the mobile robot in the given environments. Computer simulations are conducted through MATLAB software and implemented in real time by using C/C++ language running Arduino microcontroller based mobile robot. Moreover, the successful experimental results on the actual mobile robot demonstrate the effectiveness and efficiency of the proposed controller.

  10. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments

    Juan David Hernández

    2016-07-01

    Full Text Available We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV. To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario.

  11. Metastatic cancer of unknown primary in 21 dogs.

    Rossi, F; Aresu, L; Vignoli, M; Buracco, P; Bettini, G; Ferro, S; Gattino, F; Ghiani, F; Costantino, R; Ressel, L; Bellei, E; Marconato, L

    2015-03-01

    The aim of this retrospective study was to describe clinical features, treatment and outcome of 21 dogs with metastatic cancer of unknown primary (MCUP), a biopsy-proven malignancy being diagnosed at a metastatic stage, in which the anatomical origin of the primary tumour cannot be detected. All dogs underwent total-body computed tomography. Signalment, type and duration of clinical signs, metastasis site, pathology results, treatment and outcome were recorded. Carcinoma was the most common diagnosis (57.1%), followed by sarcoma, melanoma and mast cell tumour. The median number of disease sites per dog was 2, with bones, lymph nodes, lungs and spleen being the most frequent metastatic locations. The median survival for all dogs was 30 days. Overall, a primary site was not identified in 20 (95.2%) dogs. MCUP encompasses a variety of different pathologic entities and harbours a poor prognosis. © 2013 Blackwell Publishing Ltd.

  12. Distributed Synchronization Control of Multiagent Systems With Unknown Nonlinearities.

    Su, Shize; Lin, Zongli; Garcia, Alfredo

    2016-01-01

    This paper revisits the distributed adaptive control problem for synchronization of multiagent systems where the dynamics of the agents are nonlinear, nonidentical, unknown, and subject to external disturbances. Two communication topologies, represented, respectively, by a fixed strongly-connected directed graph and by a switching connected undirected graph, are considered. Under both of these communication topologies, we use distributed neural networks to approximate the uncertain dynamics. Decentralized adaptive control protocols are then constructed to solve the cooperative tracker problem, the problem of synchronization of all follower agents to a leader agent. In particular, we show that, under the proposed decentralized control protocols, the synchronization errors are ultimately bounded, and their ultimate bounds can be reduced arbitrarily by choosing the control parameter appropriately. Simulation study verifies the effectiveness of our proposed protocols.

  13. Keratosis of unknown significance and leukoplakia: a preliminary study.

    Woo, Sook-Bin; Grammer, Rebecca L; Lerman, Mark A

    2014-12-01

    The objectives were to (1) determine the frequency of specific diagnoses in a series of white lesions, and (2) describe the nature of keratotic lesions that are neither reactive nor dysplastic. White lesions were analyzed and diagnosed as reactive keratoses, dysplastic/malignant, or keratoses of unknown significance (KUS). Of the 1251 specimens that were evaluated, 703 met criteria for inclusion, and approximately 75% were reactive, 10% dysplastic/malignant, and 14% KUS. Excluding reactive keratoses, 43% were dysplastic/malignant and 57% were KUS. Reactive keratoses were the most common white lesions followed by lichen planus. Dysplastic/malignant lesions constituted almost 50% of all true leukoplakias. KUS constituted the remaining cases and do not show typical reactive histopathology as well as clear dysplasia. They may represent evolving or devolving reactive keratoses but may also represent the very earliest dysplasia phenotype. Clinical findings may be helpful in differentiating the two. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Villitis of unknown aetiology: correlation of recurrence with clinical outcome.

    Feeley, L

    2010-01-01

    Villitis of unknown aetiology (VUA) is associated with adverse pregnancy outcome. Consequently, an ability to predict recurrence could be clinically relevant. We examined placentas where villitis was diagnosed in a previous pregnancy to establish the risk of recurrence and outcome. A total of 304 cases of VUA were diagnosed in our laboratory over a 4-year period. Subsequently, 19 of this cohort had a second placenta examined histologically. Recurrence and clinical outcome were recorded. Villitis recurred in 7 of 19 cases (37%). There was a high level of adverse pregnancy outcome in this cohort overall, characterised by small for gestational age infants and stillbirth, particularly in cases with high-grade villitis. We identified recurrent villitis more frequently than previously reported. Our findings confirm an association between high-grade villitis and poor outcome. Adequately powered prospective studies are required to determine if enhanced surveillance of subsequent pregnancies is indicated following a diagnosis of villitis.

  15. Chronic kidney disease of unknown etiology in agricultural communities.

    Almaguer, Miguel; Herrera, Raúl; Orantes, Carlos M

    2014-04-01

    In recent years, Central America, Egypt, India and Sri Lanka have reported a high prevalence of chronic kidney disease of unknown etiology in agricultural communities, predominantly among male farmworkers. This essay examines the disease's case definitions, epidemiology (disease burden, demographics, associated risk factors) and causal hypotheses, by reviewing published findings from El Salvador, Nicaragua, Costa Rica, Sri Lanka, Egypt and India. The range of confirmed chronic kidney disease prevalence was 17.9%-21.1%. Prevalence of reduced glomerular filtration (homemade alcohol use and family history of chronic kidney disease. There is no strong evidence for a single cause, and multiple environmental, occupational and social factors are probably involved. Further etiological research is needed, plus interventions to reduce preventable risk factors.

  16. A Brief Introduction on Mystery, the Unknown, Surprise

    Sean Scanlan

    2012-03-01

    Full Text Available In this age of globalization, this age of so many ways to know—and so many ways to know things so quickly—it is both satisfying and deeply unnerving to come upon things and events that are really hard to understand, things and events so shocking or strange or mysterious, that they seem Unknown. Perhaps even unknowable. The first note of NANO Issue 2 focuses on an unsolved murder and reveals a mystery that is confounding, creepy, and yet oddly compelling. In “Karr’s Kill Cult: Virtual Cults and Pseudo-Killing in the Digital Age,” Jeremy Biles and Brian Collins explore the edges of where cyber-crime threatens to turn real—and vice versa. In the second note, Jennifer Ballengee compares Oedipus at Colonus with Don DeLillo’s Falling Man.

  17. Cancer of unknown primary origin: a case report

    Elisa De Carlo

    2013-03-01

    Full Text Available Carcinoma of unknown primary origin (CUP accounts for 2-10% of all malignancies. The apparent absence of the primary tumour, the development of early, uncommon systemic metastases and the resistance to therapy and poor prognosis are hallmarks of this heterogeneous clinical entity and are a challenge for physicians. The diagnostic workup of patients with CUP includes a large amount of histopathological examination, as well as the use of imaging techniques that often fail to identify the primary tumour. Therefore, the optimal workup and treatment for these patients remains to be determined. Molecular diagnostic tools, such as DNA microarray analysis, could help in the search for "lost" CUP origin and guide the further treatment approach. We report the case of a 66-year-old man, with mediastinal lymph nodes metastasis of carcinoma and neurological syndrome with diplopia and balance disorders, in which many exams have been performed without finding the primary tumour.

  18. Searching for unknown transfusion-transmitted hepatitis viruses

    Edgren, G.; Hjalgrim, H.; Rostgaard, K.

    2018-01-01

    Background: Both hepatitis B and C viruses were transmitted through blood transfusion before implementation of donor screening. The existence of additional, yet unknown transfusion transmittable agents causing liver disease could have important public health implications. Methods: Analyses were...... 1992 to account for the effect of screening for hepatitis C virus. Results: A total of 1 482 922 transfused patients were included in the analyses. Analyses showed evidence of transfusion transmission of liver diseases before, but not after the implementation of hepatitis C virus screening in 1992...... for transfusion transmission of agents causing liver disease after the implementation of screening for hepatitis B and C, and suggest that if such transmission does occur, it is rare....

  19. Analysing Trust Transitivity and The Effects of Unknown Dependence

    Touhid Bhuiyan

    2010-03-01

    Full Text Available Trust can be used to improve online automated recommendation within a given domain. Trust transitivity is used to make it successful. But trust transitivity has different interpretations. Trust and trust transitivity; both are the human mental phenomenon and for this reason, there is no such thing as objective transitivity. Trust transitivity and trust fusion both are important elements in computational trust. This paper analyses the parameter dependence problem in trust transitivity and proposes some definitions considering the effects of base rate. In addition, it also proposes belief functions based on subjective logic to analyse trust transitivity of three specified cases with sensitive and insensitive based rate. Then it presents a quantitative analysis of the effects of unknown dependence problem in an interconnected network environment; such Internet.

  20. Heuristic method for searching global maximum of multimodal unknown function

    Kamei, K; Araki, Y; Inoue, K

    1983-06-01

    The method is composed of three kinds of searches. They are called g (grasping)-mode search, f (finding)-mode search and c (confirming)-mode search. In the g-mode search and the c-mode search, a heuristic method is used which was extracted from search behaviors of human subjects. In f-mode search, the simplex method is used which is well known as a search method for unimodal unknown function. Each mode search and its transitions are shown in the form of flowchart. The numerical results for one-dimensional through six-dimensional multimodal functions prove the proposed search method to be an effective one. 11 references.

  1. Calculation of Unknown Preoperative K Readings in Postrefractive Surgery Patients

    Nicola Rosa

    2018-01-01

    Full Text Available Purpose. To determine the unknown preoperative K readings (Kpre to be used in history-based methods, for intraocular lens (IOL power calculation in patients who have undergone myopic photorefractive keratectomy (PRK. Methods. A regression formula generated from the left eyes of 174 patients who had undergone PRK for myopia or for myopic astigmatism was compared with other methods in 168 right eyes. The Pearson index and paired t-test were utilized for statistical analysis. Results. The differences between Kpre and those obtained with the other methods were as follows: 0.61 ± 0.94 D (range: −3.94 to 2.05 D, p<0.01 subtracting the effective treatment, 0.01 ± 0.86 D (range: −2.61 to 2.34 D, p=0.82 with Rosa’s formula, −0.02 ± 1.31 D (range: −3.43 to 3.68 D, p=0.82 with the current study formula, and −0.43 ± 1.40 D (range: −3.98 to 3.12 D, p<0.01 utilizing a mean K (Km of 43.5 D. Conclusions. These formulas may permit the utilization of history-based methods, that is, the double-K method in calculating the IOL power following PRK when Kpre are unknown.

  2. Smooth extrapolation of unknown anatomy via statistical shape models

    Grupp, R. B.; Chiang, H.; Otake, Y.; Murphy, R. J.; Gordon, C. R.; Armand, M.; Taylor, R. H.

    2015-03-01

    Several methods to perform extrapolation of unknown anatomy were evaluated. The primary application is to enhance surgical procedures that may use partial medical images or medical images of incomplete anatomy. Le Fort-based, face-jaw-teeth transplant is one such procedure. From CT data of 36 skulls and 21 mandibles separate Statistical Shape Models of the anatomical surfaces were created. Using the Statistical Shape Models, incomplete surfaces were projected to obtain complete surface estimates. The surface estimates exhibit non-zero error in regions where the true surface is known; it is desirable to keep the true surface and seamlessly merge the estimated unknown surface. Existing extrapolation techniques produce non-smooth transitions from the true surface to the estimated surface, resulting in additional error and a less aesthetically pleasing result. The three extrapolation techniques evaluated were: copying and pasting of the surface estimate (non-smooth baseline), a feathering between the patient surface and surface estimate, and an estimate generated via a Thin Plate Spline trained from displacements between the surface estimate and corresponding vertices of the known patient surface. Feathering and Thin Plate Spline approaches both yielded smooth transitions. However, feathering corrupted known vertex values. Leave-one-out analyses were conducted, with 5% to 50% of known anatomy removed from the left-out patient and estimated via the proposed approaches. The Thin Plate Spline approach yielded smaller errors than the other two approaches, with an average vertex error improvement of 1.46 mm and 1.38 mm for the skull and mandible respectively, over the baseline approach.

  3. A 'range test' for determining scatterers with unknown physical properties

    Potthast, Roland; Sylvester, John; Kusiak, Steven

    2003-06-01

    We describe a new scheme for determining the convex scattering support of an unknown scatterer when the physical properties of the scatterers are not known. The convex scattering support is a subset of the scatterer and provides information about its location and estimates for its shape. For convex polygonal scatterers the scattering support coincides with the scatterer and we obtain full shape reconstructions. The method will be formulated for the reconstruction of the scatterers from the far field pattern for one or a few incident waves. The method is non-iterative in nature and belongs to the type of recently derived generalized sampling schemes such as the 'no response test' of Luke-Potthast. The range test operates by testing whether it is possible to analytically continue a far field to the exterior of any test domain Omegatest. By intersecting the convex hulls of various test domains we can produce a minimal convex set, the convex scattering support of which must be contained in the convex hull of the support of any scatterer which produces that far field. The convex scattering support is calculated by testing the range of special integral operators for a sampling set of test domains. The numerical results can be used as an approximation for the support of the unknown scatterer. We prove convergence and regularity of the scheme and show numerical examples for sound-soft, sound-hard and medium scatterers. We can apply the range test to non-convex scatterers as well. We can conclude that an Omegatest which passes the range test has a non-empty intersection with the infinity-support (the complement of the unbounded component of the complement of the support) of the true scatterer, but cannot find a minimal set which must be contained therein.

  4. Identification of unknown sample using NAA, EDXRF, XRD techniques

    Dalvi, Aditi A.; Swain, K.K.; Chavan, Trupti; Remya Devi, P.S.; Wagh, D.N.; Verma, R.

    2015-01-01

    Analytical Chemistry Division (ACD), Bhabha Atomic Research Centre (BARC) receives samples from law enforcement agencies such as Directorate of Revenue Intelligence, Customs for analysis. Five unknown grey powdered samples were received for identification and were suspected to be Iridium (Ir). Identification of unknown sample is always a challenging task and suitable analytical techniques have to be judiciously utilized for arriving at the conclusion. Qualitative analysis was carried out using Jordan Valley, EX-3600 M Energy dispersive X-ray fluorescence (EDXRF) spectrometer at ACD, BARC. A SLP series LEO Si (Li) detector (active area: 30 mm 2 ; thickness: 3.5 mm; resolution: 140 eV at 5.9 keV of Mn K X-ray) was used during the measurement and only characteristic X-rays of Ir (Lα: 9.17 keV and Lβ: 10.70 keV) was seen in the X-ray spectrum. X-ray diffraction (XRD) measurement results indicated that the Ir was in the form of metal. To confirm the XRD data, neutron activation analysis (NAA) was carried out by irradiating samples and elemental standards (as comparator) in graphite reflector position of Advanced Heavy Water Reactor Critical Facility (AHWR CF) reactor, BARC, Mumbai. After suitable decay period, gamma activity measurements were carried out using 45% HPGe detector coupled to 8 k multi channel analyzer. Characteristic gamma line at 328.4 keV of the activation product 194 Ir was used for quantification of iridium and relative method of NAA was used for concentration calculations. NAA results confirmed that all the samples were Iridium metal. (author)

  5. Structural dynamic modifications via models

    The study shows that as many as half of the matrix ... the dynamicist's analytical modelling skill which would appear both in the numerator as. Figure 2. ..... Brandon J A 1990 Strategies for structural dynamic modification (New York: John Wiley).

  6. Modifications to Replacement Costs System

    Godec, M.

    1989-01-01

    The purpose of this memorandum is to document the improvements and modifications made to the Replacement Costs of Crude Oil (REPCO) Supply Analysis System. While some of this work was performed under our previous support contract to DOE/ASFE, we are presenting all modifications and improvements are presented here for completeness. The memo primarily documents revisions made to the Lower-48 Onshore Model. Revisions and modifications made to other components and models in the REPCO system which are documented elsewhere are only highlighted in this memo. Generally, the modifications made to the Lower-48 Onshore Model reflect changes that have occurred in domestic drilling, oil field costs, and reserves since 1982, the date of the most recent available data used for the original Replacement Costs report, published in 1985

  7. Standard approach to plant modifications

    Mecredy, R.C.

    1988-01-01

    Organizational and management approaches to the design, installation, and turnover of nuclear plant modifications have changed dramatically in the last 10 to 15 yr. In response to these changes, organizational and individual responsibilities have been defined and management systems have been established at Rochester Gas and Electric (RG and E) Corporation to ensure that high-quality plant modifications are installed in a timely manner that satisfies user needs at minimal cost

  8. Bacterial anoxygenic photosynthesis on plant leaf surfaces.

    Atamna-Ismaeel, Nof; Finkel, Omri; Glaser, Fabian; von Mering, Christian; Vorholt, Julia A; Koblížek, Michal; Belkin, Shimshon; Béjà, Oded

    2012-04-01

    The aerial surface of plants, the phyllosphere, is colonized by numerous bacteria displaying diverse metabolic properties that enable their survival in this specific habitat. Recently, we reported on the presence of microbial rhodopsin harbouring bacteria on the top of leaf surfaces. Here, we report on the presence of additional bacterial populations capable of harvesting light as a means of supplementing their metabolic requirements. An analysis of six phyllosphere metagenomes revealed the presence of a diverse community of anoxygenic phototrophic bacteria, including the previously reported methylobacteria, as well as other known and unknown phototrophs. The presence of anoxygenic phototrophic bacteria was also confirmed in situ by infrared epifluorescence microscopy. The microscopic enumeration correlated with estimates based on metagenomic analyses, confirming both the presence and high abundance of these microorganisms in the phyllosphere. Our data suggest that the phyllosphere contains a phylogenetically diverse assemblage of phototrophic species, including some yet undescribed bacterial clades that appear to be phyllosphere-unique. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  9. Bacterial phylogeny structures soil resistomes across habitats

    Forsberg, Kevin J.; Patel, Sanket; Gibson, Molly K.; Lauber, Christian L.; Knight, Rob; Fierer, Noah; Dantas, Gautam

    2014-05-01

    Ancient and diverse antibiotic resistance genes (ARGs) have previously been identified from soil, including genes identical to those in human pathogens. Despite the apparent overlap between soil and clinical resistomes, factors influencing ARG composition in soil and their movement between genomes and habitats remain largely unknown. General metagenome functions often correlate with the underlying structure of bacterial communities. However, ARGs are proposed to be highly mobile, prompting speculation that resistomes may not correlate with phylogenetic signatures or ecological divisions. To investigate these relationships, we performed functional metagenomic selections for resistance to 18 antibiotics from 18 agricultural and grassland soils. The 2,895 ARGs we discovered were mostly new, and represent all major resistance mechanisms. We demonstrate that distinct soil types harbour distinct resistomes, and that the addition of nitrogen fertilizer strongly influenced soil ARG content. Resistome composition also correlated with microbial phylogenetic and taxonomic structure, both across and within soil types. Consistent with this strong correlation, mobility elements (genes responsible for horizontal gene transfer between bacteria such as transposases and integrases) syntenic with ARGs were rare in soil by comparison with sequenced pathogens, suggesting that ARGs may not transfer between soil bacteria as readily as is observed between human pathogens. Together, our results indicate that bacterial community composition is the primary determinant of soil ARG content, challenging previous hypotheses that horizontal gene transfer effectively decouples resistomes from phylogeny.

  10. The unknown-unknowns: Revealing the hidden insights in massive biomedical data using combined artificial intelligence and knowledge networks

    Chris Yoo

    2017-12-01

    Full Text Available Genomic data is estimated to be doubling every seven months with over 2 trillion bases from whole genome sequence studies deposited in Genbank in just the last 15 years alone. Recent advances in compute and storage have enabled the use of artificial intelligence techniques in areas such as feature recognition in digital pathology and chemical synthesis for drug development. To apply A.I. productively to multidimensional data such as cellular processes and their dysregulation, the data must be transformed into a structured format, using prior knowledge to create contextual relationships and hierarchies upon which computational analysis can be performed. Here we present the organization of complex data into hypergraphs that facilitate the application of A.I. We provide an example use case of a hypergraph containing hundreds of biological data values and the results of several classes of A.I. algorithms applied in a popular compute cloud. While multiple, biologically insightful correlations between disease states, behavior, and molecular features were identified, the insights of scientific import were revealed only when exploration of the data included visualization of subgraphs of represented knowledge. The results suggest that while machine learning can identify known correlations and suggest testable ones, the greater probability of discovering unexpected relationships between seemingly independent variables (unknown-unknowns requires a context-aware system – hypergraphs that impart biological meaning in nodes and edges. We discuss the implications of a combined hypergraph-A.I. analysis approach to multidimensional data and the pre-processing requirements for such a system.

  11. Kriging with Unknown Variance Components for Regional Ionospheric Reconstruction

    Ling Huang

    2017-02-01

    Full Text Available Ionospheric delay effect is a critical issue that limits the accuracy of precise Global Navigation Satellite System (GNSS positioning and navigation for single-frequency users, especially in mid- and low-latitude regions where variations in the ionosphere are larger. Kriging spatial interpolation techniques have been recently introduced to model the spatial correlation and variability of ionosphere, which intrinsically assume that the ionosphere field is stochastically stationary but does not take the random observational errors into account. In this paper, by treating the spatial statistical information on ionosphere as prior knowledge and based on Total Electron Content (TEC semivariogram analysis, we use Kriging techniques to spatially interpolate TEC values. By assuming that the stochastic models of both the ionospheric signals and measurement errors are only known up to some unknown factors, we propose a new Kriging spatial interpolation method with unknown variance components for both the signals of ionosphere and TEC measurements. Variance component estimation has been integrated with Kriging to reconstruct regional ionospheric delays. The method has been applied to data from the Crustal Movement Observation Network of China (CMONOC and compared with the ordinary Kriging and polynomial interpolations with spherical cap harmonic functions, polynomial functions and low-degree spherical harmonic functions. The statistics of results indicate that the daily ionospheric variations during the experimental period characterized by the proposed approach have good agreement with the other methods, ranging from 10 to 80 TEC Unit (TECU, 1 TECU = 1 × 1016 electrons/m2 with an overall mean of 28.2 TECU. The proposed method can produce more appropriate estimations whose general TEC level is as smooth as the ordinary Kriging but with a smaller standard deviation around 3 TECU than others. The residual results show that the interpolation precision of the

  12. How to know unknown fungi: the role of a herbarium.

    Brock, Patrick M; Döring, Heidi; Bidartondo, Martin I

    2009-01-01

    The development of a universal approach to the identification of fungi from the environment is impeded by the limited number and narrow phylogenetic range of the named internal transcribed spacer DNA sequences available on GenBank. The goal here was to assess the potential impact of systematic DNA sequencing from a fungal herbarium collection. DNA sequences were generated from a diverse set of 279 specimens deposited at the fungal herbarium of the Royal Botanic Gardens at Kew (UK) and bioinformatic analyses were used to study their overlap with the public database. It is estimated that c. 70% of the herbarium taxonomic diversity is not yet represented in GenBank and that a further c. 10% of our sequences match solely to 'environmental samples' or fungi otherwise unidentified. Here it is shown that the unsampled diversity residing in fungal herbaria can substantially enlarge the coverage of GenBank's fully identified sequence pool to ameliorate the problem of environmental unknowns and to aid in the detection of truly novel fungi by molecular data.

  13. Developing Probabilistic Safety Performance Margins for Unknown and Underappreciated Risks

    Benjamin, Allan; Dezfuli, Homayoon; Everett, Chris

    2015-01-01

    Probabilistic safety requirements currently formulated or proposed for space systems, nuclear reactor systems, nuclear weapon systems, and other types of systems that have a low-probability potential for high-consequence accidents depend on showing that the probability of such accidents is below a specified safety threshold or goal. Verification of compliance depends heavily upon synthetic modeling techniques such as PRA. To determine whether or not a system meets its probabilistic requirements, it is necessary to consider whether there are significant risks that are not fully considered in the PRA either because they are not known at the time or because their importance is not fully understood. The ultimate objective is to establish a reasonable margin to account for the difference between known risks and actual risks in attempting to validate compliance with a probabilistic safety threshold or goal. In this paper, we examine data accumulated over the past 60 years from the space program, from nuclear reactor experience, from aircraft systems, and from human reliability experience to formulate guidelines for estimating probabilistic margins to account for risks that are initially unknown or underappreciated. The formulation includes a review of the safety literature to identify the principal causes of such risks.

  14. Systemic treatment of cancer of unknown primary origin

    Reckova, M.

    2013-01-01

    Cancer of unknown primary origin (CUP) comprises a heterogenous group of cancers with distinct biology and prognosis. There is, however, a specific group of patients with curable diseases, or incurable diseases with good prognosis. The main aim of treatment in the group of patients with CUP is timely initiation of therapy in the cases of curable disease. There is no known standard of care in the cases of CUP with poor prognosis, but most frequently, platinum-based regimens are used. In the cases of specific immunohistochemistry (IHC) or molecular gene expression profile, there are used the treatment regimens similar to those used in the patients with known primary tumor and similar IHC or molecular profile. Currently, most of data in patients with CUP are from phase II clinical trials. Thus proficiently designed phase III randomized clinical trials with translation research is priority, with aim to improve our knowledge and personalize treatment of such heterogenous group of patients as is a group of patients with CUP. (author)

  15. Radiotherapeutic concepts in cancer of unknown primary site

    Krug, D.; Debus, J.; Sterzing, F.

    2014-01-01

    The term cancer of unknown primary (CUP) encompasses a group of entities which differ to a great extent regarding etiology, prognosis and therapeutic management. The aim of the study was an elaboration of the role of radiotherapy in CUP syndrome. Systematic literature search and specification of the available treatment options. Radiotherapy is an integral part of interdisciplinary management approaches for patients with CUP in both curative and palliative situations. Radio-oncological techniques, such as intensity-modulated radiotherapy and stereotactic body radiotherapy increase the therapeutic window. Modern diagnostic modalities from radiology and nuclear medicine are the cornerstone of radiotherapeutic interventions, especially in terms of target volume definition and pretherapeutic staging. In the interdisciplinary setting radiation oncology offers the possibility of curative and often organ preserving approaches in patients with axillary and cervical CUP. In addition, improvement and preservation of quality of life can be achieved in patients with metastatic disease. Radiation oncology is a crucial component of the interdisciplinary management of patients with CUP. Therapeutic decisions in patients with CUP should be made in an interdisciplinary setting. (orig.) [de

  16. Crowdsourcing the unknown: the satellite search for Genghis Khan.

    A Y M Lin

    Full Text Available Massively parallel collaboration and emergent knowledge generation is described through a large scale survey for archaeological anomalies within ultra-high resolution earth-sensing satellite imagery. Over 10K online volunteers contributed 30K hours (3.4 years, examined 6,000 km², and generated 2.3 million feature categorizations. Motivated by the search for Genghis Khan's tomb, participants were tasked with finding an archaeological enigma that lacks any historical description of its potential visual appearance. Without a pre-existing reference for validation we turn towards consensus, defined by kernel density estimation, to pool human perception for "out of the ordinary" features across a vast landscape. This consensus served as the training mechanism within a self-evolving feedback loop between a participant and the crowd, essential driving a collective reasoning engine for anomaly detection. The resulting map led a National Geographic expedition to confirm 55 archaeological sites across a vast landscape. A increased ground-truthed accuracy was observed in those participants exposed to the peer feedback loop over those whom worked in isolation, suggesting collective reasoning can emerge within networked groups to outperform the aggregate independent ability of individuals to define the unknown.

  17. Chronic kidney disease of unknown etiology in Sri Lanka.

    Rajapakse, Senaka; Shivanthan, Mitrakrishnan Chrishan; Selvarajah, Mathu

    2016-07-01

    In the last two decades, chronic kidney disease of unknown etiology (CKDu) has emerged as a significant contributor to the burden of chronic kidney disease (CKD) in rural Sri Lanka. It is characterized by the absence of identified causes for CKD. The prevalence of CKDu is 15.1-22.9% in some Sri Lankan districts, and previous research has found an association with farming occupations. A systematic literature review in Pubmed, Embase, Scopus, and Lilacs databases identified 46 eligible peer-reviewed articles and one conference abstract. Geographical mapping indicates a relationship between CKDu and agricultural irrigation water sources. Health mapping studies, human biological studies, and environment-based studies have explored possible causative agents. Most studies focused on likely causative agents related to agricultural practices, geographical distribution based on the prevalence and incidence of CKDu, and contaminants identified in drinking water. Nonetheless, the link between agrochemicals or heavy metals and CKDu remains to be established. No definitive cause for CKDu has been identified. Evidence to date suggests that the disease is related to one or more environmental agents, however pinpointing a definite cause for CKDu is challenging. It is plausible that CKDu is multifactorial. No specific guidelines or recommendations exist for treatment of CKDu, and standard management protocols for CKD apply. Changes in agricultural practices, provision of safe drinking water, and occupational safety precautions are recommended by the World Health Organization.

  18. Dead or Alive? Dealing with Unknown Eligibility in Longitudinal Surveys

    Watson Nicole

    2016-12-01

    Full Text Available Longitudinal surveys follow people over time and some of these people will die during the life of the panel. Through fieldwork effort, some deaths will be reported or known, but others will be unobserved due to sample members no longer being issued to field or having inconclusive fieldwork outcomes (such as a noncontact that is not followed by a contact at a later wave. The coverage of deaths identified among sample members has flow-on implications to nonresponse correction. Using the Household, Income and Labour Dynamics in Australia (HILDA Survey, four methods are used to examine the extent of missing death reports. The first method matches the sample to the national death register. The second method uses life-expectancy tables to extrapolate the expected number of deaths among the sample with unknown eligibility. The third method is similar but models deaths from data internal to the survey. The fourth method models deaths as part of the attrition process of a longitudinal survey. The last three methods are compared to the first method and the implications for the construction of balanced panel weights and subsequent population inference are explored.

  19. Physics at 13 TeV: CMS - scanning the unknown

    Antonella Del Rosso

    2014-01-01

    CMS is getting ready to use its accurate detector to scan the many ripples of the unknown physics that may lie beyond the Standard Model. Foremost in everyone’s mind is the search for signs of the production of dark matter at a man-made machine.   Interestingly, the observation of dark matter or new weakly interacting particles implies detecting that some energy has escaped, i.e. it’s missing from the upcoming proton collisions at the LHC. This is why measuring and understanding “missing energy” will be a very important step in that direction. “A large amount of missing energy is the signature for many processes of physics beyond the Standard Model. However, it’s not the only interesting signature that we will be able to exploit when the new collision energy is available,” explains Luca Malgeri, CMS Physics Coordinator. Among the interesting things not associated with missing energy are high-mass resonanc...

  20. Adaptively locating unknown steady states: Formalism and basin of attraction

    Wu, Yu; Lin, Wei

    2011-01-01

    The adaptive technique, which includes both dynamical estimators and coupling gains, has been recently verified to be practical for locating the unknown steady states numerically. This Letter, in the light of the center manifold theory for dynamical systems and the matrix spectrum principle, establishes an analytical formalism of this adaptive technique and reveals a connection between this technique and the original adaptive controller which includes only the dynamical estimator. More interestingly, in study of the well-known Lorenz system, the selections of the estimator parameters and initial values are found to be crucial to the successful application of the adaptive technique. Some Milnor-like basins of attraction with fractal structures are found quantitatively. All the results obtained in the Letter can be further extended to more general dynamical systems of higher dimensions. -- Highlights: → Establishing a new and rigorous formalism for the adaptive stabilization technique. → Showing a close connection between the adaptive technique and the original controller. → Providing feasible algorithms for simultaneous stabilization of multiple steady states. → Finding Milnor-like basins of attraction with fractal structures in adaptive control.

  1. Investigation of cervical lymph node metastasis from primary unknown carcinoma

    Sagawa, Kosuke; Terada, Tomonori; Saeki, Nobuo; Uwa, Nobuhiro; Mohri, Takeshi; Sakagami, Masafumi

    2012-01-01

    We retrospectively evaluated 41 patients with metastatic cervical tumors from unknown primary sites at the Hyogo College of Medicine between 1997 and 2007. The N stage classification of cervical lymph nodes was: N1 in 3 cases, N2a in 10 cases, N2b in 10 cases, N2c in 4 cases, and N3 in 14 cases. The histopathological diagnoses of cervical lymph node were: squamous cell carcinoma in 33 cases, adenocarcinoma in 5 cases, undifferentiated carcinoma in 2 cases, and papillary carcinoma in 1 cases. Primary tumor sites were: tonsil in 5 cases, esophaguses in 2 cases, hypopharynxies in 2 cases, and thyroid, oral floor, submandibular gland, lung, gastric and colon in 1 case each. The useful tests were gastric endoscope, positron emission tomography-computed tomography (PET-CT), and blind biopsy of tonsil. We treated 24 of the 41 patients. Therapies were: neck dissection with postoperative radiation therapy in 11 cases, neck dissection alone in 1 case, only radiation or chemoradiation therapy alone in 8 cases, and chemotherapy alone in 4 cases. The 5-year survival rate was 40.1% in all cases and 81.5% in cases who underwent neck dissection. (author)

  2. Gravity, strings and particles a journey into the unknown

    Gasperini, Maurizio

    2014-01-01

    New fundamental forces of Nature? New forms of "dark'' energy? Signals from epochs preceding the Big Bang? Is our space-time unique? Only a joint study of the three topics examined in this book – gravity, strings and particles – may provide answers to these questions. Such a study may also provide the key to solving one of the most fascinating mysteries of modern science, namely: Besides time and the three spatial dimensions, how many other dimensions exist in our universe? The book is primarily addressed to readers who do not necessarily have a specific background in physics but are nevertheless interested in discovering the originality and the possible implications of some of the amazing ideas in modern theoretical physics. The emphasis is on conveying ideas rather than explaining formulas, focusing not on what is known but -- mainly -- on what is still unknown. Many parts of the book are devoted to fundamental theoretical models and results which are potentially highly relevant for a deeper understand...

  3. Security Measurement for Unknown Threats Based on Attack Preferences

    Lihua Yin

    2018-01-01

    Full Text Available Security measurement matters to every stakeholder in network security. It provides security practitioners the exact security awareness. However, most of the works are not applicable to the unknown threat. What is more, existing efforts on security metric mainly focus on the ease of certain attack from a theoretical point of view, ignoring the “likelihood of exploitation.” To help administrator have a better understanding, we analyze the behavior of attackers who exploit the zero-day vulnerabilities and predict their attack timing. Based on the prediction, we propose a method of security measurement. In detail, we compute the optimal attack timing from the perspective of attacker, using a long-term game to estimate the risk of being found and then choose the optimal timing based on the risk and profit. We design a learning strategy to model the information sharing mechanism among multiattackers and use spatial structure to model the long-term process. After calculating the Nash equilibrium for each subgame, we consider the likelihood of being attacked for each node as the security metric result. The experiment results show the efficiency of our approach.

  4. Kidnapping Detection and Recognition in Previous Unknown Environment

    Yang Tian

    2017-01-01

    Full Text Available An unaware event referred to as kidnapping makes the estimation result of localization incorrect. In a previous unknown environment, incorrect localization result causes incorrect mapping result in Simultaneous Localization and Mapping (SLAM by kidnapping. In this situation, the explored area and unexplored area are divided to make the kidnapping recovery difficult. To provide sufficient information on kidnapping, a framework to judge whether kidnapping has occurred and to identify the type of kidnapping with filter-based SLAM is proposed. The framework is called double kidnapping detection and recognition (DKDR by performing two checks before and after the “update” process with different metrics in real time. To explain one of the principles of DKDR, we describe a property of filter-based SLAM that corrects the mapping result of the environment using the current observations after the “update” process. Two classical filter-based SLAM algorithms, Extend Kalman Filter (EKF SLAM and Particle Filter (PF SLAM, are modified to show that DKDR can be simply and widely applied in existing filter-based SLAM algorithms. Furthermore, a technique to determine the adapted thresholds of metrics in real time without previous data is presented. Both simulated and experimental results demonstrate the validity and accuracy of the proposed method.

  5. Bacterial polyhydroxyalkanoates: Still fabulous?

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Energetics of bacterial adhesion

    Loosdrecht, M.C.M. van; Zehnder, A.J.B.

    1990-01-01

    For the description of bacterial adhesion phenomena two different physico-chemical approaches are available. The first one, based on a surface Gibbs energy balance, assumes intimate contact between the interacting surfaces. The second approach, based on colloid chemical theories (DLVO theory), allows for two types of adhesion: 1) secondary minimum adhesion, which is often weak and reversible, and 2) irreversible primary minimum adhesion. In the secondary minimum adhesion a thin water film remains present between the interacting surface. The merits of both approaches are discussed in this paper. In addition, the methods available to measure the physico-chemical surface characteristics of bacteria and the influence of adsorbing (in)organic compounds, extracellular polymers and cell surface appendages on adhesion are summarized. (author) 2 figs., 1 tab., 50 refs

  7. Biosensors of bacterial cells.

    Burlage, Robert S; Tillmann, Joshua

    2017-07-01

    Biosensors are devices which utilize both an electrical component (transducer) and a biological component to study an environment. They are typically used to examine biological structures, organisms and processes. The field of biosensors has now become so large and varied that the technology can often seem impenetrable. Yet the principles which underlie the technology are uncomplicated, even if the details of the mechanisms are elusive. In this review we confine our analysis to relatively current advancements in biosensors for the detection of whole bacterial cells. This includes biosensors which rely on an added labeled component and biosensors which do not have a labeled component and instead detect the binding event or bound structure on the transducer. Methods to concentrate the bacteria prior to biosensor analysis are also described. The variety of biosensor types and their actual and potential uses are described. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Bacterial mitotic machineries

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome.......Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par...

  9. Exploring bacterial lignin degradation.

    Brown, Margaret E; Chang, Michelle C Y

    2014-04-01

    Plant biomass represents a renewable carbon feedstock that could potentially be used to replace a significant level of petroleum-derived chemicals. One major challenge in its utilization is that the majority of this carbon is trapped in the recalcitrant structural polymers of the plant cell wall. Deconstruction of lignin is a key step in the processing of biomass to useful monomers but remains challenging. Microbial systems can provide molecular information on lignin depolymerization as they have evolved to break lignin down using metalloenzyme-dependent radical pathways. Both fungi and bacteria have been observed to metabolize lignin; however, their differential reactivity with this substrate indicates that they may utilize different chemical strategies for its breakdown. This review will discuss recent advances in studying bacterial lignin degradation as an approach to exploring greater diversity in the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Studying bacterial multispecies biofilms

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the benefits...... and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial communities...

  11. Anaerobes in bacterial vaginosis

    Aggarwal A

    2003-01-01

    Full Text Available Four hundred high vaginal swabs were taken from patients attending gynaecology and obstetrics department of Govt. medical college, Amritsar. The patients were divided into four groups i.e. women in pregnancy (Group I, in labour/post partum (Group II, with abnormal vaginal discharge or bacterial vaginosis (Group III and asymptomatic women as control (Group IV. Anaerobic culture of vaginal swabs revealed that out of 400 cases, 212(53% were culture positive. Maximum isolation of anaerobes was in group III (84% followed by group II (56%, group I (36% and control group (15%. Gram positive anaerobes (69.2% out numbered gram negatives (30.8%. Among various isolates Peptostreptococcus spp. and Bacteroides spp. were predominant.

  12. Fast Multi-blind Modification Search through Tandem Mass Spectrometry*

    Na, Seungjin; Bandeira, Nuno; Paek, Eunok

    2012-01-01

    With great biological interest in post-translational modifications (PTMs), various approaches have been introduced to identify PTMs using MS/MS. Recent developments for PTM identification have focused on an unrestrictive approach that searches MS/MS spectra for all known and possibly even unknown types of PTMs at once. However, the resulting expanded search space requires much longer search time and also increases the number of false positives (incorrect identifications) and false negatives (missed true identifications), thus creating a bottleneck in high throughput analysis. Here we introduce MODa, a novel “multi-blind” spectral alignment algorithm that allows for fast unrestrictive PTM searches with no limitation on the number of modifications per peptide while featuring over an order of magnitude speedup in relation to existing approaches. We demonstrate the sensitivity of MODa on human shotgun proteomics data where it reveals multiple mutations, a wide range of modifications (including glycosylation), and evidence for several putative novel modifications. Based on the reported findings, we argue that the efficiency and sensitivity of MODa make it the first unrestrictive search tool with the potential to fully replace conventional restrictive identification of proteomics mass spectrometry data. PMID:22186716

  13. Epigenetic Modifications and Diabetic Retinopathy

    Renu A. Kowluru

    2013-01-01

    Full Text Available Diabetic retinopathy remains one of the most debilitating chronic complications, but despite extensive research in the field, the exact mechanism(s responsible for how retina is damaged in diabetes remains ambiguous. Many metabolic pathways have been implicated in its development, and genes associated with these pathways are altered. Diabetic environment also facilitates epigenetics modifications, which can alter the gene expression without permanent changes in DNA sequence. The role of epigenetics in diabetic retinopathy is now an emerging area, and recent work has shown that genes encoding mitochondrial superoxide dismutase (Sod2 and matrix metalloproteinase-9 (MMP-9 are epigenetically modified, activates of epigenetic modification enzymes, histone lysine demethylase 1 (LSD1, and DNA methyltransferase are increased, and the micro RNAs responsible for regulating nuclear transcriptional factor and VEGF are upregulated. With the growing evidence of epigenetic modifications in diabetic retinopathy, better understanding of these modifications has potential to identify novel targets to inhibit this devastating disease. Fortunately, the inhibitors and mimics targeted towards histone modification, DNA methylation, and miRNAs are now being tried for cancer and other chronic diseases, and better understanding of the role of epigenetics in diabetic retinopathy will open the door for their possible use in combating this blinding disease.

  14. The surface modification of polystyrene

    Tremlett, C.

    2000-03-01

    Polymers have ideal bulk properties for many applications. However, adhesion to many polymers is poor without surface pretreatment. This can result, for example, in peeling paint and printing, adhesive joint failure and bio-incompatibility. In applications such as painting, printing, adhesive bonding and biocompatibility, various cleaning or surface chemical modifications may be employed. A commodity polymer where pretreatment is sometimes needed is polystyrene. This project investigated, in detail, the effects of a novel method of modification namely mediated electrochemical oxidation (MEO), as a mode of surface modification on polystyrene and a comparison was made with other polymers. The resulting modification was investigated using a range of surface analysis techniques to obtain complementary information. These included, X-ray photoelectron spectroscopy, contact angles, static secondary ion mass spectrometry, atomic force microscopy, chemical derivatization, scanning electron microscopy, attenuated total reflection Fourier Transform infrared spectroscopy and composite lap shear joint testing. It has been shown that MEO modifies the surface of polystyrene introduced oxygen mainly as hydroxyl groups, and a small number of carbonyl groups, that are positioned only on the backbone hydrocarbon chain. This modification improved adhesion, was stable and samples could be stored in aqueous media. The resulting hydroxylation was further derivatized using an amino acid to provide a specialised surface. This was very different from the multiple oxygen functionalities introduced in the comparison studies by UV/ozone and plasma treatments. (author)

  15. Bacterial meningitis in immunocompromised patients

    van Veen, K.E.B.

    2018-01-01

    Bacterial meningitis is an acute infection of the meninges, in The Netherlands most commonly caused by Streptococcus pneumoniae and Neisseria meningitides. Risk factors for acquiring bacterial meningitis include a decreased function of the immune system. The aim of this thesis was to study

  16. Bacteriële meningitis

    Brouwer, M. C.; van de Beek, D.

    2012-01-01

    Bacterial meningitis is a severe disease which affects 35.000 Europeans each year and has a mortality rate of about 20%. During the past 25 years the epidemiology of bacterial meningitis has changed significantly due to the implementation of vaccination against Haemophilus influenzae, Neisseria

  17. Surface modification for interaction study with bacteria and preosteoblast cells

    Song, Qing

    Surface modification plays a pivotal role in bioengineering. Polymer coatings can provide biocompatibility and biofunctionalities to biomaterials through surface modification. In this dissertation, initiated chemical vapor deposition (iCVD) was utilized to coat two-dimensional (2D) and three-dimensional (3D) substrates with differently charged polyelectrolytes in order to generate antimicrobial and osteocompatible biomaterials. ICVD is a modified CVD technique that enables surface modification in an all-dry condition without substrate damage and solvent contamination. The free-radical polymerization allows the vinyl polymers to conformally coat on various micro- and nano-structured substrates and maintains the delicate structure of the functional groups. The vapor deposition of polycations provided antimicrobial activity to planar and porous substrates through destroying the negatively charged bacterial membrane and brought about high contact-killing efficiency (99.99%) against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli. Additionally, the polyampholytes synthesized by iCVD exhibited excellent antifouling performance against the adhesion of Gram-positive Listeria innocua and Gram-negative E. coli in phosphate buffered saline (PBS). Their antifouling activities were attributed to the electrostatic interaction and hydration layers that served as physical and energetic barriers to prevent bacterial adhesion. The contact-killing and antifouling polymers synthesized by iCVD can be applied to surface modification of food processing equipment and medical devices with the aim of reducing foodborne diseases and medical infections. Moreover, the charged polyelectrolyte modified 2D polystyrene surfaces displayed good osteocompatibility and enhanced osteogenesis of preosteoblast cells than the un-modified polystyrene surface. In order to promote osteoinduction of hydroxyapatite (HA) scaffolds, bioinspired polymer-controlled mineralization was conducted

  18. Glory on Venus and selection among the unknown UV absorbers

    Petrova, Elena V.

    2018-05-01

    The comparison of the phase profiles of glories observed on the cloud top of Venus by the Venus Monitoring Camera (Venus Express) and the light-scattering characteristics of sulfuric acid droplets, containing admixtures with a high refractive index, makes it easier to choose between some candidates for the so-called unknown UV absorber in the Venus clouds. Since among the candidates there are materials wetted and not wetted by sulfuric acid, we analyze whether small submicron particles adhered to or embedded into the 1-μm H2SO4 droplets may actually change the glory pattern normally produced by homogeneous spherical particles and what the conditions are, under which the composite particles formed in heterogeneous nucleation may still produce a glory feature. We have found that one of the most frequently considered candidates, sulfur, can hardly be responsible for the contrasts observed at 0.365 μm on the upper clouds, since it is not wetted by sulfuric acid and submicron sulfur particles, serving as condensation nuclei for sulfuric acid, can only adhere to the H2SO4 droplets rather than be enveloped by them. Such droplets decorated by sulfur blobs substantially distort the glory feature characteristic of the scattering by spherical particles or even smooth it at all, while a glory pattern is practically always seen in the images of Venus taken at small phase angles. At the same time, the grains of the other UV absorbers that can be embedded in H2SO4 droplets, e.g., the widely discussed ferric chloride, pose no problem in terms of interpretation of the observations of glory.

  19. Data Series Subtraction with Unknown and Unmodeled Background Noise

    Vitale, Stefano; Congedo, Giuseppe; Dolesi, Rita; Ferroni, Valerio; Hueller, Mauro; Vetrugno, Daniele; Weber, William Joseph; Audley, Heather; Danzmann, Karsten; Diepholz, Ingo; hide

    2014-01-01

    LISA Pathfinder (LPF), the precursor mission to a gravitational wave observatory of the European Space Agency, will measure the degree to which two test masses can be put into free fall, aiming to demonstrate a suppression of disturbance forces corresponding to a residual relative acceleration with a power spectral density (PSD) below (30 fm/sq s/Hz)(sup 2) around 1 mHz. In LPF data analysis, the disturbance forces are obtained as the difference between the acceleration data and a linear combination of other measured data series. In many circumstances, the coefficients for this linear combination are obtained by fitting these data series to the acceleration, and the disturbance forces appear then as the data series of the residuals of the fit. Thus the background noise or, more precisely, its PSD, whose knowledge is needed to build up the likelihood function in ordinary maximum likelihood fitting, is here unknown, and its estimate constitutes instead one of the goals of the fit. In this paper we present a fitting method that does not require the knowledge of the PSD of the background noise. The method is based on the analytical marginalization of the posterior parameter probability density with respect to the background noise PSD, and returns an estimate both for the fitting parameters and for the PSD. We show that both these estimates are unbiased, and that, when using averaged Welchs periodograms for the residuals, the estimate of the PSD is consistent, as its error tends to zero with the inverse square root of the number of averaged periodograms. Additionally, we find that the method is equivalent to some implementations of iteratively reweighted least-squares fitting. We have tested the method both on simulated data of known PSD and on data from several experiments performed with the LISA Pathfinder end-to-end mission simulator.

  20. CUP Syndrome-Metastatic Malignancy with Unknown Primary Tumor.

    Zaun, Gregor; Schuler, Martin; Herrmann, Ken; Tannapfel, Andrea

    2018-03-09

    2-4% of newly diagnosed cases of malignant disease involve cancer of unknown primary (CUP). This mixed entity is one of the 6 most common types of malignant disease in Germany. Highly refined treatment strategies can now be offered to patients with CUP. This review is based on pertinent publications retrieved by a selective search in PubMed with an emphasis on articles from the past decade. The current guidelines and recommendations of specialty societies were also considered in the evaluation. CUP most commonly manifests itself as metastases to the lymph nodes, lungs, liver, or bones. With the aid of imaging studies, including functional hybrid imaging and further medical examination, a primary tumor can be discovered in up to 40% of patients initially diagnosed with CUP. Immunohistochemistry guided by histomorphology often enables precise characterization of the lesion and can be supplemented, in selected cases, by molecular-genetic diagnostic evaluation. The most commonly detected types of primary tumor are cancers of the lung, pancreas, liver, and biliary system. For patients with local metastases, surgical resection or radiotherapy with curative intent is usually indicated, sometimes in the framework of a multimodal treatment concept. The median 2-year survival of patients with disseminated CUP is only 20%. For such patients, specific types of systemic therapy are recommended on the basis of the diagnostic characterization of the disease. Immune-modulatory antibodies can be effective, particularly in the treatment of CUP that has been characterized with biomarkers, but should still be considered experimental at present. A combination of conventional and innovative diagnostic methods enables the provision of highly refined therapeutic strategies to patients with CUP who are undergoing treatment in interdisciplinary cancer centers.

  1. Treatment of Regional Metastatic Melanoma of Unknown Primary Origin

    Elke J. A. H. van Beek

    2015-08-01

    Full Text Available (1 Background: The purpose of this retrospective study was to evaluate the recurrence and survival rates of metastatic melanoma of unknown primary origin (MUP, in order to further refine current recommendations for the surgical treatment; (2 Methods: Medical data of all MUP patients registered between 2000 and 2011, were analyzed. Seventy-eight patients were categorized in either lymph node (axilla, groin, head-and neck or subcutaneous MUP. Axillary node MUPs were generally treated with dissections of levels I-III, inguinal node MUPs with combined superficial and deep groin dissections, and head-and-neck node MUPs with neck dissections to various extents, based on lymph drainage patterns. Subcutaneous lesions were excised with 1–2 cm margins. The primary outcome was treatment outcomes in terms of (locoregional recurrence and survival rates; (3 Results: Lymph node MUP recurred regionally in 11% of patients, with an overall recurrence rate of 45%. In contrast, subcutaneous MUP recurred locally in 65% of patients with an overall recurrence rate of 78%. This latter group had a significantly shorter disease-free interval than patients with lymph node MUP (p = 0.000. In the entire study population, 5-year and 10-year overall survival rates were 56% and 47% respectively, with no differences observed between the various subgroups; (4 Conclusion: The relatively low regional recurrence rate after regional lymph node dissection (11% supports its current status as standard surgical treatment for lymph node MUP. Subcutaneous MUP, on the contrary, appears to recur both locally (65% and overall (78% at a significantly higher rate, suggesting a different biological behavior. However, wide local excision remains the best available option for this specific group.

  2. Known unknowns: indirect energy effects of information and communication technology

    Horner, Nathaniel C.; Shehabi, Arman; Azevedo, Inês L.

    2016-10-01

    Background. There has been sustained and growing interest in characterizing the net energy impact of information and communication technology (ICT), which results from indirect effects offsetting (or amplifying) the energy directly consumed by ICT equipment. These indirect effects may be either positive or negative, and there is considerable disagreement as to the direction of this sign as well as the effect magnitude. Literature in this area ranges from studies focused on a single service (such as e-commerce versus traditional retail) to macroeconomic studies attempting to characterize the overall impact of ICT. Methods. We review the literature on the indirect energy effect of ICT found via Google Scholar, our own research, and input from other researchers in the field. The various studies are linked to an effect taxonomy, which is synthesized from several different hierarchies present in the literature. References are further grouped according to ICT service (e.g., e-commerce, telework) and summarized by scope, method, and quantitative and qualitative findings. Review results. Uncertainty persists in understanding the net energy effects of ICT. Results of indirect energy effect studies are highly sensitive to scoping decisions and assumptions made by the analyst. Uncertainty increases as the impact scope broadens, due to complex and interconnected effects. However, there is general agreement that ICT has large energy savings potential, but that the realization of this potential is highly dependent on deployment details and user behavior. Discussion. While the overall net effect of ICT is likely to remain unknown, this review suggests several guidelines for improving research quality in this area, including increased data collection, enhancing traditional modeling studies with sensitivity analysis, greater care in scoping, less confidence in characterizing aggregate impacts, more effort on understanding user behavior, and more contextual integration across the

  3. Popular Music in Jia Zhangke’s Unknown Pleasures

    Jie Zhang

    2011-04-01

    Full Text Available With his documentary-style films reflecting upon China’s unprecedented transformation from a state-controlled to a market-driven economy, Jia Zhangke has risen from within the movement of independent Chinese cinema that began to flourish in the late 1990s to become one of the most recognized filmmakers of contemporary China. Born in 1970 and raised in the underdeveloped Shanxi Province, Jia studied film theory at Beijing Film Academy and was first noticed for his controversial “Hometown Trilogy”—'Pickpocket '('Xiao Wu', 1997, 'Platform '('Zhantai', 1999, and 'Unknown Pleasures '('Ren xiao yao', 2002. These three films, shot with handheld video camera on the streets of his hometown province, focus on the reckless changes that China’s aggressive economic growth and globalization have brought to socially marginalized groups. Like other independently made films—films that are produced with capital from outside the state-sponsored avenues and without the approval of film censorship, and that are not allowed to be shown in China’s public theaters—Jia’s first three films reach domestic audiences only through unofficial DVD copies and small-scaled screenings at universities, film bars, and art salons. His limited domestic influence sharply contrasts with the critical acclaim that he receives from international film festival audiences, who are searching for alternative film culture from China after the Fifth Generation directors. By the late 1990s, Jia had become a spokesperson for an ever-increasing group of aspiring Chinese independent filmmakers, particularly through writings and interviews that theorize independent Chinese cinema’s practice.

  4. Vestibular Function in Adults With Epilepsy of Unknown Etiology.

    Hamed, Sherifa A; Tohamy, Amal M; Oseilly, Amira M

    2017-09-01

    This study aimed to evaluate vestibular function in adults with chronic epilepsy of unknown etiology in the inter-ictal period. Epilepsy is a chronic medical disorder. Life-long therapy may be required in one-third of patients. Epilepsy is associated with comorbid somatic conditions which impairs patients' quality of life. This cross-sectional study included 28 with generalized tonic clonic (GTC) convulsions and 14 and 3 with temporal (TLE) and frontal lobe (FLE) epilepsies with secondary generalization (all were on regular carbamazepine therapy) and 40 healthy control subjects. The patients' mean age was 34.97 ± 7.35 years and the duration of illness was 18.75 ± 7.99 years. All underwent videonystagmography (VNG). Compared with controls, patients had frequent vestibular symptoms including dizziness (62.22%) (p = 0.0001) and sense of imbalance (44.44%) (p = 0.0001). Eleven patients (24.44%) had central vestibular dysfunction (p = 0.0001); 9 (20%) had mixed vestibular dysfunction and one (2.22%) had peripheral vestibular dysfunction (p = 0.0001). Abnormalities were observed in saccadic (44.4%) and pursuit (42.2%) eye movements, optokinetic nystagmus (42.2%) and positioning/positional (11.11%) and caloric (13.33%) testing. TLE and FLE were associated with more VNG abnormalities than GTC. No significant differences were observed in the demographic and clinical characteristics between patients with and without VNG abnormalities. Vestibular manifestations are frequent in patients with epilepsy. This may be a result of the permanent damaging effect of chronic epilepsy on the vestibular cortical areas and/or a toxic effect from prolonged carbamazepine therapy on the peripheral and central vestibular systems.

  5. Hyperprolactinemia after laparoscopic ovarian drilling: An unknown phenomenon

    Omrani Gholamhossein R

    2005-08-01

    Full Text Available Abstract Background The effects of ovarian drilling on the serum levels of gonadotropins and androgens have been studied previously. The aim of this study is to evaluate the effects of ovarian drilling on the serum prolactin levels and its relation to ovulation in women with polycystic ovary syndrome. Methods This is a prospective controlled study. Thirty-six women with PCOS underwent ovarian electrocauterization in university hospitals. Control group consisted of 35 ovulatory women with unexplained infertility. Hormonal assessment performed in early follicular phase of spontaneous or induced cycle before operation in the two groups and repeated one week after operation. Hormonal assay was also performed in the early follicular phase of the first post-operative menstruation, folliculometry and progesterone assay were also performed in the same cycle. Data were analyzed by "repeated measurement design, discriminant analysis, correlation coefficient, and Fisher exact test". Results Six to ten weeks after operation the serum mean +/- SD prolactin levels increased from 284.41 +/- 114.32 mIU/ml to 354.06 +/- 204.42 mIU/ml (P = 0.011. The same values for the control group were 277.73 +/- 114.65 to 277.4 +/- 111.4 (P = 0.981 respectively. Approximately 45% of subjects in PCOS group remained anovulatory in spite of decreased level of LH and testosterone. Prolactin level remained elevated in 73.2% of women who did not ovulate 6–10 weeks after the procedure. Conclusion Hyperprolactinemia after ovarian cauterization may be considered as a possible cause of anovulation in women with polycystic ovaries and improved gonadotropin and androgen levels. The cause of hyperprolactinemia is unknown. Hormonal assay particularly PRL in anovulatory patients after ovarian cauterization is recommended.

  6. Bacterial Protein-Tyrosine Kinases

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by tyrosine......Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  7. Molecular approaches for bacterial azoreductases

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  8. Circulating levels of vasoactive peptides in patients with acute bacterial meningitis

    Berg, Ronan M G; Strauss, Gitte Irene; Tofteng, Flemming

    2009-01-01

    PURPOSE: The underlying mechanisms for cerebral blood flow (CBF) abnormalities in acute bacterial meningitis (ABM) are largely unknown. Putative mediators include vasoactive peptides, e.g. calcitonin-gene related peptide (CGRP), vasoactive intestinal peptide (VIP), and endothelin-1 (ET-1), all...

  9. Effects of triclosan on bacterial community composition and Vibrio populations in natural seawater microcosms

    Lydon, Keri Ann; Glinski, Donna A.; Westrich, Jason R.; Henderson, W. Matthew; Lipp, Erin K.

    2017-01-01

    Pharmaceuticals and personal care products, including antimicrobials, can be found at trace levels in treated wastewater effluent. Impacts of chemical contaminants on coastal aquatic microbial community structure and pathogen abundance are unknown despite the potential for selection through antimicrobial resistance. In particular, 'Vibrio', a marine bacterial genus that includes several human pathogens, displays resistance to the ubiquitous antimicrobial compound triclosan. Here we demonstrat...

  10. Drug Addiction and DNA Modifications.

    Brown, Amber N; Feng, Jian

    2017-01-01

    Drug addiction is a complex disorder which can be influenced by both genetic and environmental factors. Research has shown that epigenetic modifications can translate environmental signals into changes in gene expression, suggesting that epigenetic changes may underlie the causes and possibly treatment of substance use disorders. This chapter will focus on epigenetic modifications to DNA, which include DNA methylation and several recently defined additional DNA epigenetic changes. We will discuss the functions of DNA modifications and methods for detecting them, followed by a description of the research investigating the function and consequences of drug-induced changes in DNA methylation patterns. Understanding these epigenetic changes may provide us translational tools for the diagnosis and treatment of addiction in the future.

  11. Minimal modification to tribimaximal mixing

    He Xiaogang; Zee, A.

    2011-01-01

    We explore some ways of minimally modifying the neutrino mixing matrix from tribimaximal, characterized by introducing at most one mixing angle and a CP violating phase thus extending our earlier work. One minimal modification, motivated to some extent by group theoretic considerations, is a simple case with the elements V α2 of the second column in the mixing matrix equal to 1/√(3). Modifications by keeping one of the columns or one of the rows unchanged from tribimaximal mixing all belong to the class of minimal modification. Some of the cases have interesting experimentally testable consequences. In particular, the T2K and MINOS collaborations have recently reported indications of a nonzero θ 13 . For the cases we consider, the new data sharply constrain the CP violating phase angle δ, with δ close to 0 (in some cases) and π disfavored.

  12. Improvement of Polypropylene Biological Interactions by using Superhydrophobic Surface Modification

    E. Shirani

    2018-03-01

    Full Text Available The significance of producing superhydrophobic surfaces through modification of surface chemistry and structure is in preventing or delaying biofilm formation. This is done to improve biocompatibility and chemical and biological properties of the surface by creating micro-nano multilevel rough structure; and to decrease surface free energy by Fault Tolerant Control Strategy (FTCS . Here, we produced a superhydrophobic surface through TiO2 coating and flurosilanization methods. Then, in order to evaluate the physicochemical properties of the modified surfaces, they were characterized by Scanning Electron Microscope (SEM, Fourier Transform Infrared Spectroscopy (FTIR, Contact Angle (CA, cell viability assay (using Hela and MCF-7 cancer cell lines as well as non-cancerous human fibroblast cells by MTT, Bovine Serum Abumin (BSA protein adsorption using Bradford and bacterial adhesion assay (Staphylococcus aureus and Staphylococcus epidermidis using microtiter. Results showed that contact angle and surface energey of superhydrophobic modified surface increased to 150° and decreased to 5.51 mj/m2, respectively due to physicochemical modifications of the surface. In addition, the results showed a substantial reduction in protein adsorption and bacterial cell adhesion in superhydrophobic surface.

  13. DNA modification by alkylating compounds

    Kruglyakova, E.E.

    1985-09-01

    Results are given for research on the physico-chemical properties of alkylating compounds - nitroso alkyl ureas (NAU) which possess a broad spectrum of biological activity, such as mutagenic, carcinogenic, and anti-tumor action that is due to the alkylation and carbamoylation of DNA as well as other cellular components. Identified chemical products of NAU interaction with DNA and its components are cited. Structural conversions of a DNA macromolecule resulting from its chemical modification are examined. NAU are used to discuss possible biological consequences of DNA modification. 148 references.

  14. Corrosion principles and surface modification

    Kruger, J.

    1982-01-01

    This chapter examines the important strategies provided by the newer ideas of corrosion science and engineering that surface modification techniques must utilize to help prevent corrosion, especially the most damaging kind of aqueous corrosion, localized corrosion. Provides a brief introduction to the principles underlying the phenomenon of corrosion in order to use them to discuss surface modification strategies to combat corrosion. Discusses the electrochemistry of corrosion; the thermodynamics of corrosion; the kinetics of corrosion; thermodynamic strategies; and kinetic strategies (formation of more protective passive films; resistance to breakdown; ductility; repassivation)

  15. Active hippocampal networks undergo spontaneous synaptic modification.

    Masako Tsukamoto-Yasui

    Full Text Available The brain is self-writable; as the brain voluntarily adapts itself to a changing environment, the neural circuitry rearranges its functional connectivity by referring to its own activity. How the internal activity modifies synaptic weights is largely unknown, however. Here we report that spontaneous activity causes complex reorganization of synaptic connectivity without any external (or artificial stimuli. Under physiologically relevant ionic conditions, CA3 pyramidal cells in hippocampal slices displayed spontaneous spikes with bistable slow oscillations of membrane potential, alternating between the so-called UP and DOWN states. The generation of slow oscillations did not require fast synaptic transmission, but their patterns were coordinated by local circuit activity. In the course of generating spontaneous activity, individual neurons acquired bidirectional long-lasting synaptic modification. The spontaneous synaptic plasticity depended on a rise in intracellular calcium concentrations of postsynaptic cells, but not on NMDA receptor activity. The direction and amount of the plasticity varied depending on slow oscillation patterns and synapse locations, and thus, they were diverse in a network. Once this global synaptic refinement occurred, the same neurons now displayed different patterns of spontaneous activity, which in turn exhibited different levels of synaptic plasticity. Thus, active networks continuously update their internal states through ongoing synaptic plasticity. With computational simulations, we suggest that with this slow oscillation-induced plasticity, a recurrent network converges on a more specific state, compared to that with spike timing-dependent plasticity alone.

  16. Long-term nickel exposure altered the bacterial community composition but not diversity in two contrasting agricultural soils.

    Li, Jing; Hu, Hang-Wei; Ma, Yi-Bing; Wang, Jun-Tao; Liu, Yu-Rong; He, Ji-Zheng

    2015-07-01

    Nickel pollution imposes deleterious effects on soil ecosystem. The responses of soil microorganisms to long-term nickel pollution under field conditions remain largely unknown. Here, we used high-throughput sequencing to elucidate the impacts of long-term nickel pollution on soil bacterial communities in two contrasting agricultural soils. Our results found that the soil microbial biomass carbon consistently decreased along the nickel gradients in both soils. Nickel pollution selectively favored or impeded the prevalence of several dominant bacterial guilds, in particular, Actinobacteria showed tolerance, while Acidobacteria and Planctomycetes displayed sensitivity. Despite the apparent shifts in the bacterial community composition, no clear tendency in the bacterial diversity and abundance was identified along the nickel gradients in either soil. Collectively, we provide evidence that long-term nickel pollution shifted the soil bacterial communities, resulting in the decrease of microbial biomass although the bacterial diversity was not significantly changed.

  17. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  18. The bacterial community of entomophilic nematodes and host beetles.

    Koneru, Sneha L; Salinas, Heilly; Flores, Gilberto E; Hong, Ray L

    2016-05-01

    Insects form the most species-rich lineage of Eukaryotes and each is a potential host for organisms from multiple phyla, including fungi, protozoa, mites, bacteria and nematodes. In particular, beetles are known to be associated with distinct bacterial communities and entomophilic nematodes. While entomopathogenic nematodes require symbiotic bacteria to kill and reproduce inside their insect hosts, the microbial ecology that facilitates other types of nematode-insect associations is largely unknown. To illuminate detailed patterns of the tritrophic beetle-nematode-bacteria relationship, we surveyed the nematode infestation profiles of scarab beetles in the greater Los Angeles area over a five-year period and found distinct nematode infestation patterns for certain beetle hosts. Over a single season, we characterized the bacterial communities of beetles and their associated nematodes using high-throughput sequencing of the 16S rRNA gene. We found significant differences in bacterial community composition among the five prevalent beetle host species, independent of geographical origin. Anaerobes Synergistaceae and sulphate-reducing Desulfovibrionaceae were most abundant in Amblonoxia beetles, while Enterobacteriaceae and Lachnospiraceae were common in Cyclocephala beetles. Unlike entomopathogenic nematodes that carry bacterial symbionts, insect-associated nematodes do not alter the beetles' native bacterial communities, nor do their microbiomes differ according to nematode or beetle host species. The conservation of Diplogastrid nematodes associations with Melolonthinae beetles and sulphate-reducing bacteria suggests a possible link between beetle-bacterial communities and their associated nematodes. Our results establish a starting point towards understanding the dynamic interactions between soil macroinvertebrates and their microbiota in a highly accessible urban environment. © 2016 John Wiley & Sons Ltd.

  19. Electromagnetism of Bacterial Growth

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  20. Evolution of Bacterial Suicide

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  1. Bacterial growth on macrophyte leachate and fate of bacterial production

    Findlay, S.; Carlough, L.; Crocker, M.T.; Gill, H.K.; Meyer, J.L.; Smith, P.J.

    1986-01-01

    The role bacteria play in transferring organic carbon to other trophic levels in aquatic ecosystems depends on the efficiency with which they convert dissolved organic [ 14 C]-labelled carbon into bacterial biomass and on the ability of consumers to graze bacteria. The authors have measured the conversion efficiency for bacteria growing on macrophyte-derived dissolved organic carbon and estimated the amount of bacterial production removed by grazing. Bacteria converted this DOC into new tissue with an efficiency of 53%, substantially higher than the apparent conversion efficiency of macrophyte-derived particulate organic carbon or other types of DOC. Two estimates of grazing indicate that the decline in bacterial numbers after the bloom was probably due to grazing by flagellates. These results show the significance of the bacterial link between DOC and other trophic levels

  2. Superhydrophobic cotton by fluorosilane modification

    Erasmus, E

    2009-12-01

    Full Text Available the treatment with fluorinated or silicon compounds)1-4 and by enhancing the surface roughness with a fractal structure5-8. Cotton, a cellulose-based material, that is greatly hydrophilic, is more benefited when made hydrophobic. Modification of cotton...

  3. Molecular detection of human bacterial pathogens

    Liu, Dongyou

    2011-01-01

    .... Molecular Detection of Human Bacterial Pathogens addresses this issue, with international scientists in respective bacterial pathogen research and diagnosis providing expert summaries on current...

  4. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

    Nabanita Mukherjee

    2014-12-01

    Full Text Available Public fitness centers and exercise facilities have been implicated as possible sources for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial community residing on the surfaces in these indoor environments is still unknown. In this study, we investigated the overall bacterial ecology of selected fitness centers in a metropolitan area (Memphis, TN, USA utilizing culture-independent pyrosequencing of the 16S rRNA genes. Samples were collected from the skin-contact surfaces (e.g., exercise instruments, floor mats, handrails, etc. within fitness centers. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Proteobacter and Actinobacteria, with a total of 17 bacterial families and 25 bacterial genera. Most of these bacterial genera are of human and environmental origin (including, air, dust, soil, and water. Additionally, we found the presence of some pathogenic or potential pathogenic bacterial genera including Salmonella, Staphylococcus, Klebsiella, and Micrococcus. Staphylococcus was found to be the most prevalent genus. Presence of viable forms of these pathogens elevates risk of exposure of any susceptible individuals. Several factors (including personal hygiene, surface cleaning and disinfection schedules of the facilities may be the reasons for the rich bacterial diversity found in this study. The current finding underscores the need to increase public awareness on the importance of personal hygiene and sanitation for public gym users.

  5. D-amino acids inhibit initial bacterial adhesion: thermodynamic evidence.

    Xing, Su-Fang; Sun, Xue-Fei; Taylor, Alicia A; Walker, Sharon L; Wang, Yi-Fu; Wang, Shu-Guang

    2015-04-01

    Bacterial biofilms are structured communities of cells enclosed in a self-produced hydrated polymeric matrix that can adhere to inert or living surfaces. D-Amino acids were previously identified as self-produced compounds that mediate biofilm disassembly by causing the release of the protein component of the polymeric matrix. However, whether exogenous D-amino acids could inhibit initial bacterial adhesion is still unknown. Here, the effect of the exogenous amino acid D-tyrosine on initial bacterial adhesion was determined by combined use of chemical analysis, force spectroscopic measurement, and theoretical predictions. The surface thermodynamic theory demonstrated that the total interaction energy increased with more D-tyrosine, and the contribution of Lewis acid-base interactions relative to the change in the total interaction energy was much greater than the overall nonspecific interactions. Finally, atomic force microscopy analysis implied that the hydrogen bond numbers and adhesion forces decreased with the increase in D-tyrosine concentrations. D-Tyrosine contributed to the repulsive nature of the cell and ultimately led to the inhibition of bacterial adhesion. This study provides a new way to regulate biofilm formation by manipulating the contents of D-amino acids in natural or engineered systems. © 2014 Wiley Periodicals, Inc.

  6. Computational Analysis of Uncharacterized Proteins of Environmental Bacterial Genome

    Coxe, K. J.; Kumar, M.

    2017-12-01

    Betaproteobacteria strain CB is a gram-negative bacterium in the phylum Proteobacteria and are found naturally in soil and water. In this complex environment, bacteria play a key role in efficiently eliminating the organic material and other pollutants from wastewater. To investigate the process of pollutant removal from wastewater using bacteria, it is important to characterize the proteins encoded by the bacterial genome. Our study combines a number of bioinformatics tools to predict the function of unassigned proteins in the bacterial genome. The genome of Betaproteobacteria strain CB contains 2,112 proteins in which function of 508 proteins are unknown, termed as uncharacterized proteins (UPs). The localization of the UPs with in the cell was determined and the structure of 38 UPs was accurately predicted. These UPs were predicted to belong to various classes of proteins such as enzymes, transporters, binding proteins, signal peptides, transmembrane proteins and other proteins. The outcome of this work will help better understand wastewater treatment mechanism.

  7. Fever of unknown origin; Re-evaluation of sup 67 Ga scintigraphy in detecting causes of fever

    Misaki, Takashi; Matsui, Akira; Tanaka, Fumiko; Okuno, Yoshishige; Mitsumori, Michihide; Torizuka, Tatsurou; Dokoh, Shigeharu; Hayakawa, Katsumi; Shimbo, Shin-ichirou (Kyoto City Hospital (Japan))

    1990-06-01

    Gallium-67 scintigraphy is a commonly performed imaging modality in deteting pyrogenic lesions in cases of long-standing inexplainable fever. To re-evaluate the significance of gallium imaging in such cases, a retrospective review was made of 56 scans performed in febrile patients in whom sufficient clinical and laboratory findings were obtained. Gallium scans were true positive in 30 patients, false positive in 3, true negative in 19, and false negative in 4. In the group of true positive, local inflammatory lesions were detected in 23 patients with a final diagnosis of lung tuberculosis, urinary tract infection, and inflammatory joint disease. Abnormal gallium accumulation, as shown in the other 7 patients, provided clues to the diagnosis of generalized disorders, such as hematological malignancies (n=3), systemic autoimmune diseases (n=3), and severe infectious mononucleosis (n=one). In the group of false positive, gallium imaging revealed intestinal excretion of gallium in 2 patients and physiological pulmonary hilar accumulation in one. In the true negative group of 19 patients, fever of unknown origin was resolved spontaneously in 12 patients, and with antibiotics and corticosteroids in 2 and 5 patients, respectively. Four patients having false negative scans were finally diagnosed as having urinary tract infection (n=2), bacterial meningitis (n=one), and polyarteritis (n=one). Gallium imaging would remain the technique of choice in searching for origin of unknown fever. It may also be useful for early diagnosis of systemic disease, as well as focal inflammation. (N.K.).

  8. Organizational conditions for dealing with the unknown unknown : illustrated by how a Dutch water management authority is preparing for climate change

    Termeer, C.J.A.M.; Brink, van den M.A.

    2013-01-01

    The central question of this article is the extent to which organizations, governmental authorities in particular, are able to deal with the unknown unknown. Drawing on Weick’s work on sensemaking, we introduce seven organizational conditions that can facilitate organizations to be reliable under

  9. Organizational Conditions for Dealing with The Unknown Unknown Illustrated by how a Dutch water management authority is preparing for climate change

    Termeer, Catrien J. A. M.; van den Brink, Margo A.

    2013-01-01

    The central question of this article is the extent to which organizations, governmental authorities in particular, are able to deal with the unknown unknown. Drawing on Weick's work on sensemaking, we introduce seven organizational conditions that can facilitate organizations to be reliable under

  10. Genetic manipulation of structural color in bacterial colonies

    Johansen, Villads Egede; Catón, Laura; Hamidjaja, Raditijo

    2018-01-01

    analysis, we obtained a detailed correlation of how genetic modifications alter structural color in bacterial colonies. Understanding of genotype and phenotype relations in this system opens the way to genetic engineering of on-demand living optical materials, for use as paints and living sensors.......Naturally occurring photonic structures are responsible for the bright and vivid coloration in a large variety of living organisms. Despite efforts to understand their biological functions, development, and complex optical response, little is known of the underlying genes involved...

  11. Staphylococcus aureus resistance to human defensins and evasion of neutrophil killing via the novel virulence factor MprF is based on modification of membrane lipids with L-lysine

    Peschel, A.; Jack, R.W.; Otto, M.; Collins, L.V.; Staubitz, P.; Nicholson, G.; Kalbacher, H.; Nieuwenhuizen, W.F.; Jung, G.; Tarkowski, A.; Kessel, K.P.M. van; Strijp, J.A.G. van

    2001-01-01

    Defensins, antimicrobial peptides of the innate immune system, protect human mucosal epithelia and skin against microbial infections and are produced in large amounts by neutrophils. The bacterial pathogen Staphylococcus aureus is insensitive to defensins by virtue of an unknown resistance

  12. Centrifugal compressor shape modification using a proposed inverse design method

    Niliahmadabadi, Mahdi; Poursadegh, Farzad

    2013-01-01

    This paper is concerned with a quasi-3D design method for the radial and axial diffusers of a centrifugal compressor on the meridional plane. The method integrates a novel inverse design algorithm, called ball-spine algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain, of which unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, unknown walls are composed of a set of virtual balls that move freely along specified directions called spines. The difference between target and current pressure distributions causes the flexible boundary to deform at each modification step. In validating the quasi-3D analysis code, a full 3D Navier-Stokes code is used to analyze the existing and designed compressors numerically. Comparison of the quasi-3D analysis results with full 3D analysis results shows viable agreement. The 3D numerical analysis of the current compressor shows a huge total pressure loss on the 90 .deg. bend between the radial and axial diffusers. Geometric modification of the meridional plane causes the efficiency to improve by about 10%.

  13. Centrifugal compressor shape modification using a proposed inverse design method

    Niliahmadabadi, Mahdi [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Poursadegh, Farzad [Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2013-03-15

    This paper is concerned with a quasi-3D design method for the radial and axial diffusers of a centrifugal compressor on the meridional plane. The method integrates a novel inverse design algorithm, called ball-spine algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain, of which unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, unknown walls are composed of a set of virtual balls that move freely along specified directions called spines. The difference between target and current pressure distributions causes the flexible boundary to deform at each modification step. In validating the quasi-3D analysis code, a full 3D Navier-Stokes code is used to analyze the existing and designed compressors numerically. Comparison of the quasi-3D analysis results with full 3D analysis results shows viable agreement. The 3D numerical analysis of the current compressor shows a huge total pressure loss on the 90 .deg. bend between the radial and axial diffusers. Geometric modification of the meridional plane causes the efficiency to improve by about 10%.

  14. Neurological sequelae of bacterial meningitis

    Lucas, Marjolein J.; Brouwer, Matthijs C.; van de Beek, Diederik

    2016-01-01

    We reported on occurrence and impact of neurological sequelae after bacterial meningitis. We reviewed occurrence of neurological sequelae in children and adults after pneumococcal and meningococcal meningitis. Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive

  15. Bacterial tracheitis in Down's syndrome.

    Cant, A J; Gibson, P J; West, R J

    1987-01-01

    Four children with Down's syndrome and bacterial tracheitis are described. In three the infection was due to Haemophilus influenza. In patients with Down's syndrome presenting with stridor tracheitis should be considered and appropriate treatment started.

  16. Bacterial Communities: Interactions to Scale

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  17. Bacterial flora of sturgeon fingerling

    Arani, A.S.; Mosahab, R.

    2008-01-01

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  18. Bacterial translocation: impact of probiotics

    Jeppsson, Bengt; Mangell, Peter; Adawi, Diya; Molin, Göran

    2004-01-01

    There is a considerable amount of data in humans showing that patients who cannot take in nutrients enterally have more organ failure in the intensive care unit, a less favourable prognosis, and a higher frequency of septicaemia, in particular involving bacterial species from the intestinal tract. However, there is little evidence that this is connected with translocation of bacterial species in humans. Animal data more uniformly imply the existence of such a connection. The main focus of thi...

  19. Bacterial cellulose/boehmite composites

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L.; Caiut, Jose Mauricio A.

    2011-01-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  20. Arsenic uptake in bacterial calcite

    Catelani, Tiziano; Perito, Brunella; Bellucci, Francesco; Lee, Sang Soo; Fenter, Paul; Newville, Matthew; Rimondi, Valentina; Pratesi, Giovanni; Costagliola, Pilario

    2018-02-01

    Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03 Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature.

  1. Arsenic uptake in bacterial calcite

    Catelani, Tiziano; Perito, Brunella; Bellucci, Francesco; Lee, Sang Soo; Fenter, Paul; Newville, Matthew G.; Rimondi, Valentina; Pratesi, Giovanni; Costagliola, Pilario

    2018-02-01

    Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and Xray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature.

  2. Bacterial and archaeal resistance to ionizing radiation

    Confalonieri, F; Sommer, S, E-mail: fabrice.confalonieri@u-psud.fr, E-mail: suzanne.sommer@u-psud.fr [University Paris-Sud, CNRS UMR8621, Institut de Genetique et Microbiologie, Batiments 400-409, Universite Paris-Sud, 91405 Orsay (France)

    2011-01-01

    Organisms living in extreme environments must cope with large fluctuations of temperature, high levels of radiation and/or desiccation, conditions that can induce DNA damage ranging from base modifications to DNA double-strand breaks. The bacterium Deinococcus radiodurans is known for its resistance to extremely high doses of ionizing radiation and for its ability to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Recently, extreme ionizing radiation resistance was also generated by directed evolution of an apparently radiation-sensitive bacterial species, Escherichia coli. Radioresistant organisms are not only found among the Eubacteria but also among the Archaea that represent the third kingdom of life. They present a set of particular features that differentiate them from the Eubacteria and eukaryotes. Moreover, Archaea are often isolated from extreme environments where they live under severe conditions of temperature, pressure, pH, salts or toxic compounds that are lethal for the large majority of living organisms. Thus, Archaea offer the opportunity to understand how cells are able to cope with such harsh conditions. Among them, the halophilic archaeon Halobacterium sp and several Pyrococcus or Thermococcus species, such as Thermococcus gammatolerans, were also shown to display high level of radiation resistance. The dispersion, in the phylogenetic tree, of radioresistant prokaryotes suggests that they have independently acquired radioresistance. Different strategies were selected during evolution including several mechanisms of radiation byproduct detoxification and subtle cellular metabolism modifications to help cells recover from radiation-induced injuries, protection of proteins against oxidation, an efficient DNA repair tool box, an original pathway of DNA double-strand break repair, a condensed nucleoid that may prevent the dispersion of the DNA fragments and specific radiation-induced proteins involved in

  3. Fungal-bacterial interactions and their relevance to oral health: linking the clinic and the bench.

    Diaz, Patricia I; Strausbaugh, Linda D; Dongari-Bagtzoglou, Anna

    2014-01-01

    High throughput sequencing has accelerated knowledge on the oral microbiome. While the bacterial component of oral communities has been extensively characterized, the role of the fungal microbiota in the oral cavity is largely unknown. Interactions among fungi and bacteria are likely to influence oral health as exemplified by the synergistic relationship between Candida albicans and oral streptococci. In this perspective, we discuss the current state of the field of fungal-bacterial interactions in the context of the oral cavity. We highlight the need to conduct longitudinal clinical studies to simultaneously characterize the bacterial and fungal components of the human oral microbiome in health and during disease progression. Such studies need to be coupled with investigations using disease-relevant models to mechanistically test the associations observed in humans and eventually identify fungal-bacterial interactions that could serve as preventive or therapeutic targets for oral diseases.

  4. Regional cerebral blood flow during mechanical hyperventilation in patients with acute bacterial meningitis

    Møller, Kirsten; Høgh, Peter; Larsen, Fin Stolze

    2000-01-01

    Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial...... meningitis before and during short-term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min-1) was measured during baseline ventilation and hyperventilation by single-photon emission computed tomography (SPECT) using intravenous 133Xe bolus injection. Intravenous...... in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short-term hyperventilation does not enhance these abnormalities....

  5. Fungal-bacterial interactions and their relevance to oral health: linking the clinic and the bench

    Patricia I Diaz

    2014-07-01

    Full Text Available High throughput sequencing has accelerated knowledge on the oral microbiome. While the bacterial component of oral communities has been extensively characterized, the role of the fungal microbiota in the oral cavity is largely unknown. Interactions among fungi and bacteria are likely to influence oral health as exemplified by the synergistic relationship between Candida albicans and oral streptococci. In this perspective, we discuss the current state of the field of fungal-bacterial interactions in the context of the oral cavity. We highlight the need to conduct longitudinal clinical studies to simultaneously characterize the bacterial and fungal components of the human oral microbiome in health and during disease progression. Such studies need to be coupled with investigations using disease-relevant models to mechanistically test the associations observed in humans and eventually identify fungal-bacterial interactions that could serve as preventive or therapeutic targets for oral diseases.

  6. Modeling the integration of bacterial rRNA fragments into the human cancer genome.

    Sieber, Karsten B; Gajer, Pawel; Dunning Hotopp, Julie C

    2016-03-21

    Cancer is a disease driven by the accumulation of genomic alterations, including the integration of exogenous DNA into the human somatic genome. We previously identified in silico evidence of DNA fragments from a Pseudomonas-like bacteria integrating into the 5'-UTR of four proto-oncogenes in stomach cancer sequencing data. The functional and biological consequences of these bacterial DNA integrations remain unknown. Modeling of these integrations suggests that the previously identified sequences cover most of the sequence flanking the junction between the bacterial and human DNA. Further examination of these reads reveals that these integrations are rich in guanine nucleotides and the integrated bacterial DNA may have complex transcript secondary structures. The models presented here lay the foundation for future experiments to test if bacterial DNA integrations alter the transcription of the human genes.

  7. Ion bombardment modification of surfaces

    Auciello, O.

    1984-01-01

    An historical overview of the main advances in the understanding of bombardment-induced surface topography is presented. The implantation and sputtering mechanisms which are relevant to ion bombardment modification of surfaces and consequent structural, electronic and compositional changes are described. Descriptions of plasma and ion-beam sputtering-induced film formation, primary ion-beam deposition, dual beam techniques, cluster of molecule ion-beam deposition, and modification of thin film properties by ion bombardment during deposition are presented. A detailed account is given of the analytical and computational modelling of topography from the viewpoint of first erosion theory. Finally, an account of the possible application and/or importance of textured surfaces in technologies and/or experimental techniques not considered in previous chapters is presented. refs.; figs.; tabs

  8. Epigenetic modifications in prostate cancer.

    Ngollo, Marjolaine; Dagdemir, Aslihan; Karsli-Ceppioglu, Seher; Judes, Gaelle; Pajon, Amaury; Penault-Llorca, Frederique; Boiteux, Jean-Paul; Bignon, Yves-Jean; Guy, Laurent; Bernard-Gallon, Dominique J

    2014-01-01

    Prostate cancer is the most common cancer in men and the second leading cause of cancer deaths in men in France. Apart from the genetic alterations in prostate cancer, epigenetics modifications are involved in the development and progression of this disease. Epigenetic events are the main cause in gene regulation and the three most epigenetic mechanisms studied include DNA methylation, histone modifications and microRNA expression. In this review, we summarized epigenetic mechanisms in prostate cancer. Epigenetic drugs that inhibit DNA methylation, histone methylation and histone acetylation might be able to reactivate silenced gene expression in prostate cancer. However, further understanding of interactions of these enzymes and their effects on transcription regulation in prostate cancer is needed and has become a priority in biomedical research. In this study, we summed up epigenetic changes with emphasis on pharmacologic epigenetic target agents.

  9. Exploring oxidative modifications of tyrosine

    Houée-Lévin, C; Bobrowski, K; Horakova, L

    2015-01-01

    residues are oxidised in vivo with impact on cellular homeostasis and redox signalling pathways. A notable example is tyrosine, which can undergo a number of oxidative post-translational modifications to form 3-hydroxy-tyrosine, tyrosine crosslinks, 3-nitrotyrosine and halogenated tyrosine, with different...... effects on cellular functions. Tyrosine oxidation has been studied extensively in vitro, and this has generated detailed information about the molecular mechanisms that may occur in vivo. An important aspect of studying tyrosine oxidation both in vitro and in biological systems is the ability to monitor...... residues modified and the nature of the modification. These approaches have helped understanding of the consequences of tyrosine oxidation in biological systems, especially its effects on cell signalling and cell dysfunction, linking to roles in disease. There is mounting evidence that tyrosine oxidation...

  10. Characterization of the Bacterial Community Naturally Present on Commercially Grown Basil Leaves: Evaluation of Sample Preparation Prior to Culture-Independent Techniques

    Siele Ceuppens

    2015-08-01

    Full Text Available Fresh herbs such as basil constitute an important food commodity worldwide. Basil provides considerable culinary and health benefits, but has also been implicated in foodborne illnesses. The naturally occurring bacterial community on basil leaves is currently unknown, so the epiphytic bacterial community was investigated using the culture-independent techniques denaturing gradient gel electrophoresis (DGGE and next-generation sequencing (NGS. Sample preparation had a major influence on the results from DGGE and NGS: Novosphingobium was the dominant genus for three different basil batches obtained by maceration of basil leaves, while washing of the leaves yielded lower numbers but more variable dominant bacterial genera including Klebsiella, Pantoea, Flavobacterium, Sphingobacterium and Pseudomonas. During storage of basil, bacterial growth and shifts in the bacterial community were observed with DGGE and NGS. Spoilage was not associated with specific bacterial groups and presumably caused by physiological tissue deterioration and visual defects, rather than by bacterial growth.

  11. Cradle modification for hydraulic ram

    Koons, B.M.

    1995-01-01

    The analysis of the cradle hydraulic system considers stress, weld strength, and hydraulic forces required to lift and support the cradle/pump assembly. The stress and weld strength of the cradle modifications is evaluated to ensure that they meet the requirements of the American Institute for Steel Construction (AISC 1989). The hydraulic forces are evaluated to ensure that the hydraulic system is capable of rotating the cradle and pump assembly to the vertical position (between 70 degrees and 90 degrees)

  12. Bacterial Associates Modify Growth Dynamics of the Dinoflagellate Gymnodinium catenatum.

    Bolch, Christopher J S; Bejoy, Thaila A; Green, David H

    2017-01-01

    Marine phytoplankton cells grow in close association with a complex microbial associate community known to affect the growth, behavior, and physiology of the algal host. The relative scale and importance these effects compared to other major factors governing algal cell growth remain unclear. Using algal-bacteria co-culture models based on the toxic dinoflagellate Gymnodinium catenatum , we tested the hypothesis that associate bacteria exert an independent effect on host algal cell growth. Batch co-cultures of G. catenatum were grown under identical environmental conditions with simplified bacterial communities composed of one-, two-, or three-bacterial associates. Modification of the associate community membership and complexity induced up to four-fold changes in dinoflagellate growth rate, equivalent to the effect of a 5°C change in temperature or an almost six-fold change in light intensity (20-115 moles photons PAR m -2 s -1 ). Almost three-fold changes in both stationary phase cell concentration and death rate were also observed. Co-culture with Roseobacter sp. DG874 reduced dinoflagellate exponential growth rate and led to a more rapid death rate compared with mixed associate community controls or co-culture with either Marinobacter sp. DG879, Alcanivorax sp. DG881. In contrast, associate bacteria concentration was positively correlated with dinoflagellate cell concentration during the exponential growth phase, indicating growth was limited by supply of dinoflagellate-derived carbon. Bacterial growth increased rapidly at the onset of declining and stationary phases due to either increasing availability of algal-derived carbon induced by nutrient stress and autolysis, or at mid-log phase in Roseobacter co-cultures potentially due to the onset of bacterial-mediated cell lysis. Co-cultures with the three bacterial associates resulted in dinoflagellate and bacterial growth dynamics very similar to more complex mixed bacterial community controls, suggesting that

  13. Ion bombardment modification of surfaces

    Auciello, O.

    1984-01-01

    Ion bombardment-induced modification of surfaces may be considered one of the significant scientific and technological developments of the last two decades. The understanding acquired concerning the underlying mechanisms of several phenomena occurring during ion-surface interactions has led to applications within different modern technologies. These include microelectronics, surface acoustical and optical technologies, solar energy conversion, thin film technology, ion implantation metallurgy, nuclear track technology, thermonuclear fusion, vacuum technology, cold welding technology, biomedicine (implantology). It has become clear that information on many relevant advances, regarding ion bombardment modification of surfaces is dispersed among journals involving fields sometimes not clearly related. This may result, in some cases, in a loss of the type of interdisciplinary exchange of ideas, which has proved to be so fruitful for the advancement of science and technology. This book has been planned in an attempt to collect at least some of today's relevant information about the experimental and theoretical knowledge related to surface modification and its application to technology. (Auth.)

  14. Bacterial Prostatitis: Bacterial Virulence, Clinical Outcomes, and New Directions.

    Krieger, John N; Thumbikat, Praveen

    2016-02-01

    Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because Escherichia coli represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in E. coli strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of E. coli causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain E. coli might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that E. coli needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to E. coli strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic E. coli may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain.

  15. Quantification of total phosphorothioate in bacterial DNA by a bromoimane-based fluorescent method.

    Xiao, Lu; Xiang, Yu

    2016-06-01

    The discovery of phosphorothioate (PT) modifications in bacterial DNA has challenged our understanding of conserved phosphodiester backbone structure of cellular DNA. This exclusive DNA modification in bacteria is not found in animal cells yet, and its biological function in bacteria is still poorly understood. Quantitative information about the bacterial PT modifications is thus important for the investigation of their possible biological functions. In this study, we have developed a simple fluorescence method for selective quantification of total PTs in bacterial DNA, based on fluorescent labeling of PTs and subsequent release of the labeled fluorophores for absolute quantification. The method was highly selective to PTs and not interfered by the presence of reactive small molecules or proteins. The quantification of PTs in an E. coli DNA sample was successfully achieved using our method and gave a result of about 455 PTs per million DNA nucleotides, while almost no detectable PTs were found in a mammalian calf thymus DNA. With this new method, the content of phosphorothioate in bacterial DNA could be successfully quantified, serving as a simple method suitable for routine use in biological phosphorothioate related studies. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Histone modifications: Cycling with chromosomal replication

    Thon, Genevieve

    2008-01-01

    Histone modifications tend to be lost during chromosome duplication. Several recent studies suggest that the RNA interference pathway becomes active during the weakened transcriptional repression occurring at centromeres in S phase, resulting in the re-establishment of histone modifications...

  17. Antibiotic Modification of Native Grafts: Improving upon nature's scaffolds

    Ketonis, Constantinos

    The use of allograft bone in orthopaedics, spine surgery and dentistry is invaluable for helping restore bone defects and promote osteointegration. However, one, and perhaps the most important, problem associated with the use of allograft is infection. It is a devastating complication for patients and physicians alike, and necessitates repeated surgeries, extended treatment and often times results in increased morbidity and poor outcomes. Previous attempts to incorporate antibiotics into allograft by soaking the graft in antibiotic solution have enjoyed limited success in providing adequate protection against bacterial colonization. To overcome problems associated with controlled release systems, I have described a novel chemical modification that allows for the attachment of vancomycin, or other antibiotics, to free amines of allograft bone thus rendering the graft bactericidal over a long time period. This modification, as evaluated by immunohistochemistry, allowed for the uniform and stable attachment of antibiotics to allograft without adversely affecting its potential for incorporation with bone. Modified allograft, placed in the presence of S. aureus, did not allow colonization by bacteria as evaluated by fluorescent imaging, scanning microscopy, and direct bacterial counts. More importantly, inhibition of bacterial colonization resulted in prevention of biofilm formation. Furthermore, I show that the spectrum of activity of the parent antibiotic was maintained, as the construct was not active against E. coli challenges. Comparison of this technology with simple antibiotic incorporation demonstrated that the covalently-coupled antibiotic did not elute from the bone, but rather remained attached and active on the surface for times out to one year, times that are far longer than currently can be achieved with the elution technologies. Despite its potent activity against bacteria, modified bone remained biocompatible allowing attachment of osteoblastic

  18. GENETIC CONTROL OF RESTRICTION AND MODIFICATION IN ESCHERICHIA COLI1

    Boyer, Herbert

    1964-01-01

    Boyer, Herbert (Yale University, New Haven, Conn.). Genetic control of restriction and modification in Escherichia coli. J. Bacteriol. 88:1652–1660. 1964.—Bacterial crosses with K-12 strains of Escherichia coli as Hfr donors (Hfr Hayes, Hfr Cavalli, and Hfr P4X-6) and B/r strains of E. coli as F− recipients were found to differ from crosses between K-12 Hfr donors and K-12 F− recipients in two ways: (i) recombinants (leu, pro, lac, and gal) did not appear at discrete time intervals but did appear simultaneously 30 min after matings were initiated, and (ii) the linkage of unselected markers to selected markers was reduced. Integration of a genetic region linked to the threonine locus of K-12 into the B/r genome resulted in a hybrid which no longer gave anomalous results in conjugation experiments. A similar region of the B strain was introduced into the K-12 strain, which then behaved as a typical B F− recipient. These observations are interpreted as the manifestation of host-controlled modification and restriction on the E. coli chromosome. This was verified by experiments on the restriction and modification of the bacteriophage lambda, F-lac, F-gal, and sex-factor, F1. It was found that the genetic region that controlled the mating responses of the K-12 and B/r strains also controlled the modification and restriction properties of these two strains. The genes responsible for the restricting and modifying properties of the K-12 and B strains of E. coli were found to be allelic, linked to each other, and linked to the threonine locus. PMID:14240953

  19. BIOCHAR MODIFICATION, THERMAL STABILITY AND TOXICITY OF PRODUCTS MODIFICATION

    Romana FRIEDRICHOVÁ

    2017-12-01

    Full Text Available Biochar is a product obtained from processing of waste biomass. The main application of biochar is in soil and environment remediation. Some new applications of this carbonaceous material take advantage of its adsorption capacity use it as a heterogeneous catalyst for energy storage and conversion etc. This contribution describes thermal stability of the original biochar. It discusses biochar modified by chemical and physical methods including a new compound of biochar-graphene oxide. The purpose of the modifications is to increase its active surface to introduce active functional groups into the carbon structure of biochar in relation to fire safety and toxicity of those products.

  20. Chronic bacterial prostatitis and chronic pelvic pain syndrome.

    Bowen, Diana K; Dielubanza, Elodi; Schaeffer, Anthony J

    2015-08-27

    Chronic prostatitis can cause pain and urinary symptoms, and can occur either with an active infection (chronic bacterial prostatitis [CBP]) or with only pain and no evidence of bacterial causation (chronic pelvic pain syndrome [CPPS]). Bacterial prostatitis is characterised by recurrent urinary tract infections or infection in the prostate with the same bacterial strain, which often results from urinary tract instrumentation. However, the cause and natural history of CPPS are unknown and not associated with active infection. We conducted a systematic overview and aimed to answer the following clinical questions: What are the effects of treatments for chronic bacterial prostatitis? What are the effects of treatments for chronic pelvic pain syndrome? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). At this update, searching of electronic databases retrieved 131 studies. After deduplication and removal of conference abstracts, 67 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 51 studies and the further review of 16 full publications. Of the 16 full articles evaluated, three systematic reviews and one RCT were included at this update. We performed a GRADE evaluation for 14 PICO combinations. In this systematic overview, we categorised the efficacy for 12 interventions based on information relating to the effectiveness and safety of 5 alpha-reductase inhibitors, allopurinol, alpha-blockers, local injections of antimicrobial drugs, mepartricin, non-steroidal anti-inflammatory drugs (NSAIDs), oral antimicrobial drugs, pentosan polysulfate, quercetin, sitz baths, transurethral microwave thermotherapy (TUMT), and transurethral resection of the prostate (TURP).

  1. Mass spectrometry-based bacterial proteomics: focus on dermatological associated microbial pathogens

    Youcef eSoufi

    2016-02-01

    Full Text Available The composition of human skin acts as a natural habitat for various bacterial species that function in a commensal and symbiotic fashion. In a healthy individual, bacterial flora serves to protect the host. Under certain conditions such as minor trauma, impaired host immunity, or environmental factors, the risk of developing skin infections is increased. Although a large majority of bacterial associated skin infections are common, a portion can potentially manifest into clinically significant morbidity. For example, Gram positive species that typically reside on the skin such as Staphylococcus and Streptococcus can cause numerous epidermal (impetigo, ecthyma and dermal (cellulitis, necrotizing fasciitis, erysipelas skin infections. Moreover, the increasing incidence of bacterial antibiotic resistance represents a serious challenge to modern medicine and threatens the health care system. Therefore, it is critical to develop tools and strategies that can allow us to better elucidate the nature and mechanism of bacterial virulence. To this end, mass spectrometry (MS-based proteomics has been revolutionizing biomedical research, and has positively impacted the microbiology field. Advances in MS technologies have paved the way for numerous bacterial proteomes and their respective post translational modifications (PTMs to be accurately identified and quantified in a high throughput and robust fashion. This technological platform offers critical information with regards to signal transduction, adherence, and microbial-host interactions associated with bacterial pathogenesis. This mini-review serves to highlight the current progress proteomics has contributed towards the understanding of bacteria that are associated with skin related diseases, infections, and antibiotic resistance.

  2. Energy conservation potential of surface modification technologies

    Le, H.K.; Horne, D.M.; Silberglitt, R.S.

    1985-09-01

    This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

  3. Beyond gene expression: the impact of protein post-translational modifications in bacteria.

    Cain, Joel A; Solis, Nestor; Cordwell, Stuart J

    2014-01-31

    The post-translational modification (PTM) of proteins plays a critical role in the regulation of a broad range of cellular processes in eukaryotes. Yet their role in governing similar systems in the conventionally presumed 'simpler' forms of life has been largely neglected and, until recently, was thought to occur only rarely, with some modifications assumed to be limited to higher organisms alone. Recent developments in mass spectrometry-based proteomics have provided an unparalleled power to enrich, identify and quantify peptides with PTMs. Additional modifications to biological molecules such as lipids and carbohydrates that are essential for bacterial pathophysiology have only recently been detected on proteins. Here we review bacterial protein PTMs, focusing on phosphorylation, acetylation, proteolytic degradation, methylation and lipidation and the roles they play in bacterial adaptation - thus highlighting the importance of proteomic techniques in a field that is only just in its infancy. This article is part of a Special Issue entitled: Trends in Microbial Proteomics. © 2013 Elsevier B.V. All rights reserved.

  4. Biodiversity and global health—hubris, humility and the unknown

    Stephens, Carolyn

    2012-03-01

    biodiversity and well-being; and the links of biodiversity to the green economy in the context of sustainable development and poverty alleviation. References [1] Schuiteman A et al 2011 Nocturne for an unknown pollinator: first description of a night-flowering orchid (Bulbophyllum nocturnum) Bot. J. Linean Soc. 167 344-50 [2] Kinver M and Gill V 2011 Botanists discover 'remarkable' night-flowering orchid BBC News Science and Environment (www.bbc.co.uk/news/science-environment-15818662) [3] Rudd M A 2011 Scientists' opinions on the global status and management of biological diversity Conserv. Biol. 25 1165-75 [4] Bottrill M C et al 2008 Is conservation triage just smart decision making? Trends Ecol. Evol. 23 649-54 [5] Parr M J et al 2009 Why we should aim for zero extinction Trends Ecol. Evol. 24 181 Bottrill M C et al 2009 Finite conservation funds mean triage is unavoidable Trends Ecol. Evol. 24 183-4 [6] Pushpangadan P and Behl H M 2005 Environment & Biodiversity: Agenda for Future (Lucknow: International Society of Environmental Botanists) (http://isebindia.com/icpep-3/icpep3-s-2.html) [7] Alves R and Rosa I 2007 Biodiversity, traditional medicine and public health: where do they meet? J. Ethnobiol. Ethnomed. 3 14 [8] Center for Biodiversity and Conservation 1997 Biodiversity and Human Health: A Guide for Policymakers (New York: American Museum of Natural History) [9] Chivian E 1997 Global environmental degradation and biodiversity loss: implications for human health Biodiversity and Human Health ed F Grifo and J Rosenthal (Washington, DC: Island) pp 7-38 [10] UNEP-WCMC 2011 Health and Well Being of Communities Directly Dependent on Ecosystem Goods and Services: An Indicator for the Convention on Biological Diversity (Cambridge: UNEP-World Conservation Monitoring Centre) [11] Nettleton C, Stephens C and Bristow F 2007 Utz Wachil: a study of indigenous perceptions of health and environment in five countries Ecohealth 4 461-772 [12] Jones G P et al 2004 Coral decline

  5. Bacterial community in ancient permafrost alluvium at the Mammoth Mountain (Eastern Siberia).

    Brouchkov, Anatoli; Kabilov, Marsel; Filippova, Svetlana; Baturina, Olga; Rogov, Victor; Galchenko, Valery; Mulyukin, Andrey; Fursova, Oksana; Pogorelko, Gennady

    2017-12-15

    Permanently frozen (approx. 3.5Ma) alluvial Neogene sediments exposed in the Aldan river valley at the Mammoth Mountain (Eastern Siberia) are unique, ancient, and poorly studied permafrost environments. So far, the structure of the indigenous bacterial community has remained unknown. Use of 16S metagenomic analysis with total DNA isolation using DNA Spin Kit for Soil (MO-Bio) and QIAamp DNA Stool Mini Kit (Qiagen) has revealed the major and minor bacterial lineages in the permafrost alluvium sediments. In sum, 61 Operational Taxonomic Units (OTUs) with 31,239 reads (Qiagen kit) and 15,404 reads (Mo-Bio kit) could be assigned to the known taxa. Only three phyla, Bacteroidetes, Proteobacteria and Firmicutes, comprised >5% of the OTUs abundance and accounted for 99% of the total reads. OTUs pertaining to the top families (Chitinophagaceae, Caulobacteraceae, Sphingomonadaceae, Bradyrhizobiaceae, Halomonadaceae) held >90% of reads. The abundance of Actinobacteria was less (0.7%), whereas members of other phyla (Deinococcus-Thermus, Cyanobacteria/Chloroplast, Fusobacteria, and Acidobacteria) constituted a minor fraction of reads. The bacterial community in the studied ancient alluvium differs from other permafrost sediments, mainly by predominance of Bacteroidetes (>52%). The diversity of this preserved bacterial community has the potential to cause effects unknown if prompted to thaw and spread with changing climate. Therefore, this study elicits further reason to study how reintroduction of these ancient bacteria could affect the surrounding ecosystem, including current bacterial species. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Influence of environmental variables on the structure and composition of soil bacterial communities in natural and constructed wetlands.

    Arroyo, Paula; Sáenz de Miera, Luis E; Ansola, Gemma

    2015-02-15

    Bacteria are key players in wetland ecosystems, however many essential aspects regarding the ecology of wetland bacterial communities remain unknown. The present study characterizes soil bacterial communities from natural and constructed wetlands through the pyrosequencing of 16S rDNA genes in order to evaluate the influence of wetland variables on bacterial community composition and structure. The results show that the composition of soil bacterial communities was significantly associated with the wetland type (natural or constructed wetland), the type of environment (lagoon, Typha or Salix) and three continuous parameters (SOM, COD and TKN). However, no clear associations were observed with soil pH. Bacterial diversity values were significantly lower in the constructed wetland with the highest inlet nutrient concentrations. The abundances of particular metabolic groups were also related to wetland characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Abdominal radiation causes bacterial translocation

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-01-01

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa

  8. Bacterial Degradation of Aromatic Compounds

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  9. Antibiotic resistance of bacterial biofilms

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains....... Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance...

  10. Epigenetic modifications and diabetic nephropathy

    Marpadga A. Reddy

    2012-09-01

    Full Text Available Diabetic nephropathy (DN is a major complication associated with both type 1 and type 2 diabetes, and a leading cause of end-stage renal disease. Conventional therapeutic strategies are not fully efficacious in the treatment of DN, suggesting an incomplete understanding of the gene regulation mechanisms involved in its pathogenesis. Furthermore, evidence from clinical trials has demonstrated a “metabolic memory” of prior exposure to hyperglycemia that continues to persist despite subsequent glycemic control. This remains a major challenge in the treatment of DN and other vascular complications. Epigenetic mechanisms such as DNA methylation, nucleosomal histone modifications, and noncoding RNAs control gene expression through regulation of chromatin structure and function and post-transcriptional mechanisms without altering the underlying DNA sequence. Emerging evidence indicates that multiple factors involved in the etiology of diabetes can alter epigenetic mechanisms and regulate the susceptibility to diabetes complications. Recent studies have demonstrated the involvement of histone lysine methylation in the regulation of key fibrotic and inflammatory genes related to diabetes complications including DN. Interestingly, histone lysine methylation persisted in vascular cells even after withdrawal from the diabetic milieu, demonstrating a potential role of epigenetic modifications in metabolic memory. Rapid advances in high-throughput technologies in the fields of genomics and epigenomics can lead to the identification of genome-wide alterations in key epigenetic modifications in vascular and renal cells in diabetes. Altogether, these findings can lead to the identification of potential predictive biomarkers and development of novel epigenetic therapies for diabetes and its associated complications.

  11. Modification Propagation in Complex Networks

    Mouronte, Mary Luz; Vargas, María Luisa; Moyano, Luis Gregorio; Algarra, Francisco Javier García; Del Pozo, Luis Salvador

    To keep up with rapidly changing conditions, business systems and their associated networks are growing increasingly intricate as never before. By doing this, network management and operation costs not only rise, but are difficult even to measure. This fact must be regarded as a major constraint to system optimization initiatives, as well as a setback to derived economic benefits. In this work we introduce a simple model in order to estimate the relative cost associated to modification propagation in complex architectures. Our model can be used to anticipate costs caused by network evolution, as well as for planning and evaluating future architecture development while providing benefit optimization.

  12. New biphasic monocomponent composite material obtained by the partial oxypropylation of bacterial cellulose

    Rosa, Joyce Rover; Silva, Ingrid S.V. da; Pasquini, Daniel; Santos, Daniele B. dos; Barud, Hernane S.; Ribeiro, Sidney J.L.

    2011-01-01

    This study aimed to partial oxypropylation of bacterial cellulose (CB), as well as the characterization of pure CB, oxypropylated CB (CBO) and oxypropylated CB after Soxhlet extraction with hexane (CBOE). The oxypropylation reaction was carried out by propylene oxide polymerization, catalyzed by KOH, in the presence of CB The CB samples, before and after modification, were subjected to analysis of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was possible verify that the partial transformation of bacterial cellulose by inserting a layer of thermoplastic polymer on its surface occurred efficiently, obtaining a biphasic monocomponent composite material. (author)

  13. Off-Policy Actor-Critic Structure for Optimal Control of Unknown Systems With Disturbances.

    Song, Ruizhuo; Lewis, Frank L; Wei, Qinglai; Zhang, Huaguang

    2016-05-01

    An optimal control method is developed for unknown continuous-time systems with unknown disturbances in this paper. The integral reinforcement learning (IRL) algorithm is presented to obtain the iterative control. Off-policy learning is used to allow the dynamics to be completely unknown. Neural networks are used to construct critic and action networks. It is shown that if there are unknown disturbances, off-policy IRL may not converge or may be biased. For reducing the influence of unknown disturbances, a disturbances compensation controller is added. It is proven that the weight errors are uniformly ultimately bounded based on Lyapunov techniques. Convergence of the Hamiltonian function is also proven. The simulation study demonstrates the effectiveness of the proposed optimal control method for unknown systems with disturbances.

  14. Bacterial computing with engineered populations.

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  15. Laser surface modification of PEEK

    Riveiro, A., E-mail: ariveiro@uvigo.es [Applied Physics Department, University of Vigo ETSII, Lagoas-Marcosende, 9, Vigo 36310 (Spain); Centro Universitario de la Defensa, Escuela Naval Militar, Plaza de Espana 2, 36920 Marin (Spain); Soto, R.; Comesana, R.; Boutinguiza, M.; Val, J. del; Quintero, F.; Lusquinos, F.; Pou, J. [Applied Physics Department, University of Vigo ETSII, Lagoas-Marcosende, 9, Vigo 36310 (Spain)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Role of laser irradiation wavelength on the surface modification of PEEK (polyether-ether-ketone) was investigated. Black-Right-Pointing-Pointer Adequate processing conditions to improve wettability, roughness, and cell adhesion characteristics are determined. Black-Right-Pointing-Pointer A design of experiments (DOE) methodology was performed. Black-Right-Pointing-Pointer UV (355 nm) radiation is the most promising laser radiation for improving the adhesive surface properties of PEEK. - Abstract: Polyether-ether-ketone (PEEK) is a synthetic thermoplastic polymer with excellent mechanical and chemical properties, which make it attractive for the field of reconstructive surgery. Nevertheless, this material has a poor interfacial biocompatibility due to its large chemical stability which induces poor adhesive bonding properties. The possibilities of enhancing the PEEK adhesive properties by laser treatments have been explored in the past. This paper presents a systematic approach to discern the role of laser irradiation wavelength on the surface modification of PEEK under three laser wavelengths ({lambda} = 1064, 532, and 355 nm) with the aim to determine the most adequate processing conditions to increase the roughness and wettability, the main parameters affecting cell adhesion characteristics of implants. Overall results show that the ultraviolet ({lambda} = 355 nm) laser radiation is the most suitable one to enhance surface wettability of PEEK.

  16. Influence of major-groove chemical modifications of DNA on transcription by bacterial RNA polymerases

    Raindlová, Veronika; Janoušková, Martina; Slavíčková, Michaela; Perlíková, Pavla; Boháčová, Soňa; Milisavljevič, Nemanja; Šanderová, Hana; Benda, Martin; Barvík, I.; Krásný, Libor; Hocek, Michal

    2016-01-01

    Roč. 44, č. 7 (2016), s. 3000-3012 ISSN 0305-1048 R&D Projects: GA ČR GA14-04289S Institutional support: RVO:61388963 ; RVO:61388971 Keywords : Escherichia coli RNA * Bacillus subtilis * restriction endonucleases Subject RIV: CC - Organic Chemistry; EE - Microbiology, Virology (MBU-M) Impact factor: 10.162, year: 2016 http://nar.oxfordjournals.org/content/44/7/3000.full

  17. Amplicon sequencing of bacterial microbiota in abortion material from cattle.

    Vidal, Sara; Kegler, Kristel; Posthaus, Horst; Perreten, Vincent; Rodriguez-Campos, Sabrina

    2017-10-10

    Abortions in cattle have a significant economic impact on animal husbandry and require prompt diagnosis for surveillance of epizootic infectious agents. Since most abortions are not epizootic but sporadic with often undetected etiologies, this study examined the bacterial community present in the placenta (PL, n = 32) and fetal abomasal content (AC, n = 49) in 64 cases of bovine abortion by next generation sequencing (NGS) of the 16S rRNA gene. The PL and AC from three fetuses of dams that died from non-infectious reasons were included as controls. All samples were analyzed by bacterial culture, and 17 were examined by histopathology. We observed 922 OTUs overall and 267 taxa at the genus level. No detectable bacterial DNA was present in the control samples. The microbial profiles of the PL and AC differed significantly, both in their composition (PERMANOVA), species richness and Chao-1 (Mann-Whitney test). In both organs, Pseudomonas was the most abundant genus. The combination of NGS and culture identified opportunistic pathogens of interest in placentas with lesions, such as Vibrio metschnikovii, Streptococcus uberis, Lactococcus lactis and Escherichia coli. In placentas with lesions where culturing was unsuccessful, Pseudomonas and unidentified Aeromonadaceae were identified by NGS displaying high number of reads. Three cases with multiple possible etiologies and placentas presenting lesions were detected by NGS. Amplicon sequencing has the potential to uncover unknown etiological agents. These new insights on cattle abortion extend our focus to previously understudied opportunistic abortive bacteria.

  18. Combining Inverse and Transport Modeling to Estimate Bacterial Loading and Transport in a Tidal Embayment

    Mac Sisson

    2016-11-01

    Full Text Available Poquoson River is a tidal coastal embayment located along the Western Shore of the Chesapeake Bay about 4 km south of the York River mouth in the City of Poquoson and in York County, Virginia. Its drainage area has diversified land uses, including high densities of residence, agricultural, salt marsh land uses, as well as a National Wildlife Refuge. This embayment experiences elevated bacterial concentration due to excess bacterial inputs from storm water runoff, nonpoint sources, and wash off from marshes due to tide and wind-induced set-up and set-down. Bacteria can also grow in the marsh and small tributaries. It is difficult to use a traditional watershed model to simulate bacterial loading, especially in this low-lying marsh area with abundant wildlife, while runoff is not solely driven by precipitation. An inverse approach is introduced to estimate loading from unknown sources based on observations in the embayment. The estimated loadings were combined with loadings estimated from different sources (human, wildlife, agriculture, pets, etc. and input to the watershed model. The watershed model simulated long-term flow and bacterial loading and discharged to a three-dimensional transport model driven by tide, wind, and freshwater discharge. The transport model efficiently simulates the transport and fate of the bacterial concentration in the embayment and is capable of determining the loading reduction needed to improve the water quality condition of the embayment. Combining inverse, watershed, and transport models is a sound approach for simulating bacterial transport correctly in the coastal embayment with complex unknown bacterial sources, which are not solely driven by precipitation.

  19. Community-acquired bacterial meningitis

    van de Beek, Diederik; Brouwer, Matthijs; Hasbun, Rodrigo; Koedel, Uwe; Whitney, Cynthia G.; Wijdicks, Eelco

    2016-01-01

    Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma

  20. Food irradiation and bacterial toxins

    Tranter, H.S.; Modi, N.K.; Hambleton, P.; Melling, J.; Rose, S.; Stringer, M.F.

    1987-01-01

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods. (author)

  1. How carotenoids protect bacterial photosynthesis.

    Cogdell, R J; Howard, T D; Bittl, R; Schlodder, E; Geisenheimer, I; Lubitz, W

    2000-01-01

    The essential function of carotenoids in photosynthesis is to act as photoprotective agents, preventing chlorophylls and bacteriochlorophylls from sensitizing harmful photodestructive reactions in the presence of oxygen. Based upon recent structural studies on reaction centres and antenna complexes from purple photosynthetic bacteria, the detailed organization of the carotenoids is described. Then with specific reference to bacterial antenna complexes the details of the photoprotective role, ...

  2. Biotechnological applications of bacterial cellulases

    Menéndez, E.; García-Fraile, Paula; Rivas, R.

    2015-01-01

    Roč. 2, č. 3 (2015), s. 163-182 ISSN 2306-5354 R&D Projects: GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : Biotechnological applications * Bacterial cellulases * Cellulose degradation Subject RIV: EE - Microbiology, Virology

  3. bacterial flora and antibiotic sensitivity

    Purulent pelvic collections are common pathologies observed in contemporary gynaecological practice. They may originate from chronic pelvic inflammatory disease, from abortions or following normal deliveries. This study was designed to compare the bacterial flora in purulent pelvic collections obtained from HIV infected ...

  4. Bacterial Biofilms and Catheters: A Key to Understanding Bacterial Strategies in Catheter-Associated Urinary Tract Infection

    J Curtis Nickel

    1992-01-01

    Full Text Available Despite major technological improvements in catheter drainage systems, the indwelling Foley catheter remains the most common cause of nosocomial infection in medical practice. By approaching this common complicated urinary tract infection from the perspective of the biofilm strategy bacteria appear to use to overcome obstacles to produce bacteriuria, one appreciates a new understanding of these infections. An adherent biofilm of bacteria in their secretory products ascends the luminal and external surface of the catheter and drainage system from a contaminated drainage spigot or urethral meatus into the bladder. If the intraluminal route of bacterial ascent is delayed by strict sterile closed drainage or addition of internal modifications to the system, the extraluminal or urethral route assumes greater importance in the development of bacteriuria, but takes significantly longer. Bacterial growth within these thick coherent biofilms confers a large measure of relative resistance to antibiotics even though the individual bacterium remains sensitive, thus accounting for the failure of antibiotic therapy. With disruption of the protective mucous layer of the bladder by mechanical irritation, the bacteria colonizing the catheter can adhere to the bladder’s mucosal surface and cause infection. An appreciation of the role of bacterial biofilms in these infections should suggest future directions for research that may ultimately reduce the risk of catheter-associated infection.

  5. Ca2+ response in neutrophils after exposure to bacterial N-formyl-methionyl-leucyl-phenylalanine: delayed response in ulcerative colitis

    Vainer, Ben; Lamberth, Kasper; Brimnes, Jens

    2003-01-01

    In acute stages of ulcerative colitis (UC), neutrophils migrate from the circulation into inflamed colonic tissue, initiated by yet unknown stimuli. The bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) is a component of the surface membrane of colonic bacteria such as Escherichia ...

  6. Evidence for Vertical Transmission of Bacterial Symbionts from Adult to Embryo in the Caribbean Sponge Svenzea zeai

    Lee, O. O.; Chui, P. Y.; Wong, Y. H.; Pawlik, J. R.; Qian, P.-Y.

    2009-01-01

    to progeny are largely unknown. In this study, both a 16S rRNA gene-based fingerprinting technique (denaturing gradient gel electrophoresis [DGGE]) and clone library analysis were applied to compare the bacterial communities associated with adults and embryos

  7. Changes in urine composition after trauma facilitate bacterial growth

    Aubron Cecile

    2012-11-01

    Full Text Available Abstract Background Critically ill patients including trauma patients are at high risk of urinary tract infection (UTI. The composition of urine in trauma patients may be modified due to inflammation, systemic stress, rhabdomyolysis, life support treatment and/or urinary catheter insertion. Methods Prospective, single-centre, observational study conducted in patients with severe trauma and without a history of UTIs or recent antibiotic treatment. The 24-hour urine samples were collected on the first and the fifth days and the growth of Escherichia coli in urine from patients and healthy volunteers was compared. Biochemical and hormonal modifications in urine that could potentially influence bacterial growth were explored. Results Growth of E. coli in urine from trauma patients was significantly higher on days 1 and 5 than in urine of healthy volunteers. Several significant modifications of urine composition could explain these findings. On days 1 and 5, trauma patients had an increase in glycosuria, in urine iron concentration, and in the concentrations of several amino acids compared to healthy volunteers. On day 1, the urinary osmotic pressure was significantly lower than for healthy volunteers. Conclusion We showed that urine of trauma patients facilitated growth of E. coli when compared to urine from healthy volunteers. This effect was present in the first 24 hours and until at least the fifth day after trauma. This phenomenon may be involved in the pathophysiology of UTIs in trauma patients. Further studies are required to define the exact causes of such modifications.

  8. Bioaccumulation and chemical modification of Tc by soil bacteria

    Henrot, J.

    1989-01-01

    Bioaccumulation and chemical modification of pertechnetate (TcO 4 -) by aerobically and anaerobically grown soil bacteria and by pure cultures of sulfate-reducing bacteria (Desulfovibrio sp.) were studied to gain insight on the possible mechanisms by which bacteria can affect the solubility of Tc in soil. Aerobically grown bacteria had no apparent effect on TcO 4 -; they did not accumulate Tc nor modify its chemical form. Anaerobically grown bacteria exhibited high bioaccumulation and reduced TcO 4 -, enabling its association with organics of the growth medium. Reduction was a metabolic process and not merely the result of reducing conditions in the growth medium. Association of Tc with bacterial polysaccharides was observed only in cultures of anaerobic bacteria. Sulfate-reducing bacteria efficiently removed Tc from solution and promoted its association with organics. Up to 70% of the total Tc in the growth medium was bioaccumulated and/or precipitated. The remaining Tc in soluble form was entirely associated with organics. Pertechnetate was not reduced by the same mechanism as dissimilatory sulfate reduction, but rather by some reducing agent released in the growth medium. A calculation of the amount of Tc that could be associated with the bacterial biomass present in soil demonstrates that high concentration ratios in cultures do not necessarily imply that bioaccumulation is an important mechanism for long-term retention of Tc in soil

  9. The Effect of Known-and-Unknown Word Combinations on Intentional Vocabulary Learning

    Kasahara, Kiwamu

    2011-01-01

    The purpose of this study is to examine whether learning a known-and-unknown word combination is superior in terms of retention and retrieval of meaning to learning a single unknown word. The term "combination" in this study means a two-word collocation of a familiar word and a word that is new to the participants. Following the results of…

  10. 48 CFR 52.222-49 - Service Contract Act-Place of Performance Unknown.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Service Contract Act-Place... Provisions and Clauses 52.222-49 Service Contract Act—Place of Performance Unknown. As prescribed in 22.1006(f), insert the following clause: Service Contract Act—Place of Performance Unknown (MAY 1989) (a...

  11. Hepatitis B immunisation in persons not previously exposed to hepatitis B or with unknown exposure status

    Mathew, Joseph L; El Dib, Regina; Mathew, Preethy J

    2008-01-01

    The benefits and harms of hepatitis B vaccination in persons not previously exposed to hepatitis B infection or with unknown exposure status have not been established.......The benefits and harms of hepatitis B vaccination in persons not previously exposed to hepatitis B infection or with unknown exposure status have not been established....

  12. Numerical method of identification of an unknown source term in a heat equation

    Fatullayev Afet Golayo?lu

    2002-01-01

    Full Text Available A numerical procedure for an inverse problem of identification of an unknown source in a heat equation is presented. Approach of proposed method is to approximate unknown function by polygons linear pieces which are determined consecutively from the solution of minimization problem based on the overspecified data. Numerical examples are presented.

  13. Surface Modification for Microreactor Fabrication

    Wladyslaw Torbicz

    2006-04-01

    Full Text Available In this paper, methods of surface modification of different supports, i.e. glass andpolymeric beads for enzyme immobilisation are described. The developed method ofenzyme immobilisation is based on Schiff’s base formation between the amino groups onthe enzyme surface and the aldehyde groups on the chemically modified surface of thesupports. The surface of silicon modified by APTS and GOPS with immobilised enzymewas characterised by atomic force microscopy (AFM, time-of-flight secondary ion massspectroscopy (ToF-SIMS and infrared spectroscopy (FTIR. The supports withimmobilised enzyme (urease were also tested in combination with microreactors fabricatedin silicon and Perspex, operating in a flow-through system. For microreactors filled withurease immobilised on glass beads (Sigma and on polymeric beads (PAN, a very high andstable signal (pH change was obtained. The developed method of urease immobilisationcan be stated to be very effective.

  14. Ion beam modification of polymers

    Sofield, C.J.; Sugden, S.; Ing, J.; Bridwell, L.B.; Wang, Y.Q.

    1993-01-01

    The implantation of polymers has received considerable attention in recent years, primarily to examine doping of conducting polymers and to increase the surface conductivity (by many orders of magnitude) of highly insulating polymers. The interest in these studies was partly motivated by possible applications to microelectronic device fabrication. More recently it has been observed that ion implantation can under some conditions lead to the formation of a hard (e.g. as hard as steel, ca. 3 MPa) and conducting surface layer. This paper will review the ion beam modification of polymers resulting from ion implantation with reference to fundamental ion-solid interactions. This leads us to examine whether or not implantation of polymers is a contradiction in terms. (Author)

  15. Soy protein modification: A review

    Barać Miroljub B.

    2004-01-01

    Full Text Available Soy protein products such as flour, concentrates and isolates are used in food formulation because of their functionality, nutritional value and low cost. To obtain their optimal nutritive and functional properties as well as desirable flavor different treatments are used. Soybean proteins can be modified by physical, chemical and enzymatic treatments. Different thermal treatments are most commonly used, while the most appropriate way of modifying soy proteins from the standpoint of safety is their limited proteolysis. These treatments cause physical and chemical changes that affect their functional properties. This review discusses three principal methods used for modification of soy protein products, their effects on dominant soy protein properties and some biologically active compounds.

  16. Prostatitis-bacterial - self-care

    ... this page: //medlineplus.gov/ency/patientinstructions/000395.htm Prostatitis - bacterial - self-care To use the sharing features ... enable JavaScript. You have been diagnosed with bacterial prostatitis . This is an infection of the prostate gland. ...

  17. Adjunctive Corticosteroids in Adults with Bacterial Meningitis

    van de Beek, Diederik; de Gans, Jan

    2005-01-01

    Bacterial meningitis is a complex disorder in which neurologic injury is caused, in part, by the causative organism and, in part, by the host's own inflammatory response. In studies of experimental bacterial meningitis, adjuvant treatment with corticosteroids, specifically dexamethasone, has

  18. Antimicrobial susceptibility in community-acquired bacterial ...

    Objectives: To determine the antimicrobial susceptibility patterns of Streptococcus pneumoniae and Haemophilus influenzae, two bacterial pathogens commonly associated with communityacquired pneumonia. Design: Cross-sectional study. Setting: Bacterial isolates were obtained from adults suspected to have ...

  19. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Stoica-Guzun, Anicuta [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania)], E-mail: astoica@mt.pub.ro; Stroescu, Marta; Tache, Florin [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania); Zaharescu, Traian [Advanced Research Institute for Electrical Engineering, 313 Splaiul Unirii, 030138 Bucharest (Romania)], E-mail: zaharescut@icpe-ca.ro; Grosu, Elena [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania)

    2007-12-15

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of {gamma}-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

  20. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

    2007-01-01

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell

  1. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

    2007-12-01

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

  2. Bacterial cells with improved tolerance to polyamines

    2017-01-01

    Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds.......Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds....

  3. Bacterial cells with improved tolerance to polyols

    2017-01-01

    The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds.......The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds....

  4. Bacterial diversity in permanently cold and alkaline ikaite columns from Greenland.

    Schmidt, Mariane; Priemé, Anders; Stougaard, Peter

    2006-12-01

    Bacterial diversity in alkaline (pH 10.4) and permanently cold (4 degrees C) ikaite tufa columns from the Ikka Fjord, SW Greenland, was investigated using growth characterization of cultured bacterial isolates with Terminal-restriction fragment length polymorphism (T-RFLP) and sequence analysis of bacterial 16S rRNA gene fragments. More than 200 bacterial isolates were characterized with respect to pH and temperature tolerance, and it was shown that the majority were cold-active alkaliphiles. T-RFLP analysis revealed distinct bacterial communities in different fractions of three ikaite columns, and, along with sequence analysis, it showed the presence of rich and diverse bacterial communities. Rarefaction analysis showed that the 109 sequenced clones in the 16S rRNA gene library represented between 25 and 65% of the predicted species richness in the three ikaite columns investigated. Phylogenetic analysis of the 16S rRNA gene sequences revealed many sequences with similarity to alkaliphilic or psychrophilic bacteria, and showed that 33% of the cloned sequences and 33% of the cultured bacteria showed less than 97% sequence identity to known sequences in databases, and may therefore represent yet unknown species.

  5. The Bacterial Sequential Markov Coalescent.

    De Maio, Nicola; Wilson, Daniel J

    2017-05-01

    Bacteria can exchange and acquire new genetic material from other organisms directly and via the environment. This process, known as bacterial recombination, has a strong impact on the evolution of bacteria, for example, leading to the spread of antibiotic resistance across clades and species, and to the avoidance of clonal interference. Recombination hinders phylogenetic and transmission inference because it creates patterns of substitutions (homoplasies) inconsistent with the hypothesis of a single evolutionary tree. Bacterial recombination is typically modeled as statistically akin to gene conversion in eukaryotes, i.e. , using the coalescent with gene conversion (CGC). However, this model can be very computationally demanding as it needs to account for the correlations of evolutionary histories of even distant loci. So, with the increasing popularity of whole genome sequencing, the need has emerged for a faster approach to model and simulate bacterial genome evolution. We present a new model that approximates the coalescent with gene conversion: the bacterial sequential Markov coalescent (BSMC). Our approach is based on a similar idea to the sequential Markov coalescent (SMC)-an approximation of the coalescent with crossover recombination. However, bacterial recombination poses hurdles to a sequential Markov approximation, as it leads to strong correlations and linkage disequilibrium across very distant sites in the genome. Our BSMC overcomes these difficulties, and shows a considerable reduction in computational demand compared to the exact CGC, and very similar patterns in simulated data. We implemented our BSMC model within new simulation software FastSimBac. In addition to the decreased computational demand compared to previous bacterial genome evolution simulators, FastSimBac provides more general options for evolutionary scenarios, allowing population structure with migration, speciation, population size changes, and recombination hotspots. FastSimBac is

  6. TWO MODIFICATIONS OF SCALERS FOR RATE STUDIES

    Hodgson, T. S.; Gordon, B. E.

    1964-04-15

    Two simple modifications to nuclear scalers have been developed. The first involves an automatic stepping switch which permits a single scaler to be actuated by up to four Geiger counters in sequence and to record the time to reach a preset count for each. The second modification is designed to pick a pulse off a conventional scaler when a preset count has been reached and to use the pulse to actuate a recorder. Both modifications considerably extend the utility of conventional scalers.

  7. Modification of metallic corrosion by ion implantation

    Clayton, C.R.

    1981-01-01

    This review will consider some of the properties of surface alloys, formed by ion implantation, which are effective in modifying corrosion behaviour. Examples will be given of the modification of the corrosion behaviour of pure metals, steels and other engineering alloys, resulting from implantation with metals and metalloids. Emphasis will be given to the modification of anodic processes produced by ion implantation since a review will be given elsewhere in the proceedings concerning the modification of cathodic processes. (orig.)

  8. Proteomic analysis of post-translational modifications

    Mann, Matthias; Jensen, Ole N

    2003-01-01

    Post-translational modifications modulate the activity of most eukaryote proteins. Analysis of these modifications presents formidable challenges but their determination generates indispensable insight into biological function. Strategies developed to characterize individual proteins are now...... systematically applied to protein populations. The combination of function- or structure-based purification of modified 'subproteomes', such as phosphorylated proteins or modified membrane proteins, with mass spectrometry is proving particularly successful. To map modification sites in molecular detail, novel...

  9. Chemical Modifications of Starch: Microwave Effect

    Lewicka, Kamila; Siemion, Przemysław; Kurcok, Piotr

    2015-01-01

    This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation ...

  10. Bacterial reproductive pathogens of cats and dogs.

    Graham, Elizabeth M; Taylor, David J

    2012-05-01

    With the notable exception of Brucella canis, exogenous bacterial pathogens are uncommon causes of reproductive disease in cats and dogs. Most bacterial reproductive infections are endogenous, and predisposing factors for infection are important. This article reviews the etiology, pathogenesis, clinical presentation, diagnosis, treatment, and public health significance of bacterial reproductive pathogens in cats and dogs.

  11. Chemical Modifications of Starch: Microwave Effect

    Kamila Lewicka

    2015-01-01

    Full Text Available This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation are discussed. Properties of microwave radiation and its impact on starch (with particular regard to modifications described in literature are characterized.

  12. BACTERIAL COMMUNITY DYNAMICS AND ECOTOXICOLOGICAL ASSESSMENT DURING BIOREMEDIATION OF SOILS CONTAMINATED BY BIODIESEL AND DIESEL/BIODIESEL BLENDS.

    Matos, G I; Junior, C S; Oliva, T C; Subtil, D F; Matsushita, L Y; Chaves, A L; Lutterbach, M T; Sérvulo, E F; Agathos, S N; Stenuit, B

    2015-01-01

    The gradual introduction of biodiesel in the Brazilian energy landscape has primarily occurred through its blending with conventional petroleum diesel (e.g., B20 (20% biodiesel) and B5 (5% biodiesel) formulations). Because B20 and lower-level blends generally do not require engine modifications, their use as transportation fuel is increasing in the Brazilian distribution networks. However, the environmental fate of low-level biodiesel blends and pure biodiesel (B100) is poorly understood and the ecotoxicological-safety endpoints of biodiesel-contaminated environments are unknown. Using laboratory microcosms consisting of closed reactor columns filled with clay loam soil contaminated with pure biodiesel (EXPB100) and a low-level blend (EXPB5) (10% w/v), this study presents soil ecotoxicity assessement and dynamics of culturable heterotrophic bacteria. Most-probable-number (MPN) procedures for enumeration of bacteria, dehydrogenase assays and soil ecotoxicological tests using Eisenia fetida have been performed at different column depths over the course of incubation. After 60 days of incubation, the ecotoxicity of EXPB100-derived samples showed a decrease from 63% of mortality to 0% while EXPB5-derived samples exhibited a reduction from 100% to 53% and 90% on the top and at the bottom of the reactor column, respectively. The dehydrogenase activity of samples from EXPB100 and EXPB5 increased significantly compared to pristine soil after 60 days of incubation. Growth of aerobic bacterial biomass was only observed on the top of the reactor column while the anaerobic bacteria exhibited significant growth at different column depths in EXPB100 and EXPB5. These preliminary results suggest the involvement of soil indigenous microbiota in the biodegradation of biodiesel and blends. However, GC-FID analyses for quantification of fatty acid methyl esters (FAMEs) and aliphatic hydrocarbons and targeted sequencing of 16S rRNA tags using illumina platforms will provide important

  13. Bacterial cheating limits antibiotic resistance

    Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

    2012-02-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

  14. Bacterial streamers in curved microchannels

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  15. Collective Functionality through Bacterial Individuality

    Ackermann, Martin

    According to the conventional view, the properties of an organism are a product of nature and nurture - of its genes and the environment it lives in. Recent experiments with unicellular organisms have challenged this view: several molecular mechanisms generate phenotypic variation independently of environmental signals, leading to variation in clonal groups. My presentation will focus on the causes and consequences of this microbial individuality. Using examples from bacterial genetic model systems, I will first discuss different molecular and cellular mechanisms that give rise to bacterial individuality. Then, I will discuss the consequences of individuality, and focus on how phenotypic variation in clonal populations of bacteria can promote interactions between individuals, lead to the division of labor, and allow clonal groups of bacteria to cope with environmental uncertainty. Variation between individuals thus provides clonal groups with collective functionality.

  16. Bacterial adhesion and biofilm formation on surfaces of variable roughness and hydrophobicity

    Tang, Lone; Pillai, Saju; Iversen, Anders

    L.Biofilm formation on surfaces in food production and processing can deteriorate the quality of food products and be a hazard to consumers. The food industry currently uses a number of approaches to either remove biofilm or prevent its formation. Due to the inherent resilience of bacteria...... in biofilm, a particularly attractive approach is the modification of surfaces with the aim to impede the first step in biofilm formation, namely bacterial adhesion. Surface properties such as hydrophobicity, roughness and predisposition for fouling by protein are recognised as important in bacterial...... adhesion. Sol-gel technology and the recent availability of organic modified silicas have lead to development of hybrid organic/inorganic glass ceramic coatings with specialised surface properties. In this study we investigate bacterial adhesion and the subsequent biofilm formation on stainless steel (SS...

  17. The bacterial sequential Markov coalescent

    De Maio, N; Wilson, DJ

    2017-01-01

    Bacteria can exchange and acquire new genetic material from other organisms directly and via the environment. This process, known as bacterial recombination, has a strong impact on the evolution of bacteria, for example leading to the spread of antibiotic resistance across clades and species, and to the avoidance of clonal interference. Recombination hinders phylogenetic and transmission inference because it creates patterns of substitutions that are not consistent with the hypothesis of a si...

  18. Magnetic resonance appearance of monoclonal gammopathies of unknown significance and multiple myeloma. The GRI Study Group.

    Bellaïche, L; Laredo, J D; Lioté, F; Koeger, A C; Hamze, B; Ziza, J M; Pertuiset, E; Bardin, T; Tubiana, J M

    1997-11-01

    A prospective multicenter study. To evaluate the use of magnetic resonance imaging, in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. Although multiple myeloma has been studied extensively with magnetic resonance imaging, to the authors' knowledge, no study has evaluated the clinical interest of magnetic resonance imaging in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. The magnetic resonance examinations of the thoracolumbar spine in 24 patients with newly diagnosed monoclonal gammopathies of unknown significance were compared with those performed in 44 patients with newly diagnosed nontreated multiple myeloma. All findings on magnetic resonance examination performed in patients with monoclonal gammopathies of unknown significance were normal, whereas findings on 38 (86%) of the 44 magnetic resonance examinations performed in patients with multiple myeloma were abnormal. Magnetic resonance imaging can be considered as an additional diagnostic tool in differentiating between monoclonal gammopathies of unknown significance and multiple myeloma, which may be helpful when routine criteria are not sufficient. An abnormal finding on magnetic resonance examination in a patient with monoclonal gammopathies of unknown significance should suggest the diagnosis of multiple myeloma after other causes of marrow signal abnormalities are excluded. Magnetic resonance imaging also may be proposed in the long-term follow-up of monoclonal gammopathies of unknown significance when a new biologic or clinical event suggests the diagnosis of malignant monoclonal gammopathy.

  19. The FUN of identifying gene function in bacterial pathogens; insights from Salmonella functional genomics.

    Hammarlöf, Disa L; Canals, Rocío; Hinton, Jay C D

    2013-10-01

    The availability of thousands of genome sequences of bacterial pathogens poses a particular challenge because each genome contains hundreds of genes of unknown function (FUN). How can we easily discover which FUN genes encode important virulence factors? One solution is to combine two different functional genomic approaches. First, transcriptomics identifies bacterial FUN genes that show differential expression during the process of mammalian infection. Second, global mutagenesis identifies individual FUN genes that the pathogen requires to cause disease. The intersection of these datasets can reveal a small set of candidate genes most likely to encode novel virulence attributes. We demonstrate this approach with the Salmonella infection model, and propose that a similar strategy could be used for other bacterial pathogens. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Bacterial sex in dental plaque.

    Olsen, Ingar; Tribble, Gena D; Fiehn, Nils-Erik; Wang, Bing-Yan

    2013-01-01

    Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

  1. Bacterial sex in dental plaque

    Ingar Olsen

    2013-06-01

    Full Text Available Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

  2. Polymorphism in Bacterial Flagella Suspensions

    Schwenger, Walter J.

    Bacterial flagella are a type of biological polymer studied for its role in bacterial motility and the polymorphic transitions undertaken to facilitate the run and tumble behavior. The naturally rigid, helical shape of flagella gives rise to novel colloidal dynamics and material properties. This thesis studies methods in which the shape of bacterial flagella can be controlled using in vitro methods and the changes the shape of the flagella have on both single particle dynamics and bulk material properties. We observe individual flagellum in both the dilute and semidilute regimes to observe the effects of solvent condition on the shape of the filament as well as the effect the filament morphology has on reptation through a network of flagella. In addition, we present rheological measurements showing how the shape of filaments effects the bulk material properties of flagellar suspensions. We find that the individual particle dynamics in suspensions of flagella can vary with geometry from needing to reptate linearly via rotation for helical filaments to the prevention of long range diffusion for block copolymer filaments. Similarly, for bulk material properties of flagella suspensions, helical geometries show a dramatic enhancement in elasticity over straight filaments while block copolymers form an elastic gel without the aid of crosslinking agents.

  3. Bacterial biofilm and associated infections

    Muhsin Jamal

    2018-01-01

    Full Text Available Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living. Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease.

  4. Bacterial Biofilms in Jones Tubes.

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  5. Bacterial Carriers for Glioblastoma Therapy

    Nalini Mehta

    2017-03-01

    Full Text Available Treatment of aggressive glioblastoma brain tumors is challenging, largely due to diffusion barriers preventing efficient drug dosing to tumors. To overcome these barriers, bacterial carriers that are actively motile and programmed to migrate and localize to tumor zones were designed. These carriers can induce apoptosis via hypoxia-controlled expression of a tumor suppressor protein p53 and a pro-apoptotic drug, Azurin. In a xenograft model of human glioblastoma in rats, bacterial carrier therapy conferred a significant survival benefit with 19% overall long-term survival of >100 days in treated animals relative to a median survival of 26 days in control untreated animals. Histological and proteomic analyses were performed to elucidate the safety and efficacy of these carriers, showing an absence of systemic toxicity and a restored neural environment in treated responders. In the treated non-responders, proteomic analysis revealed competing mechanisms of pro-apoptotic and drug-resistant activity. This bacterial carrier opens a versatile avenue to overcome diffusion barriers in glioblastoma by virtue of its active motility in extracellular space and can lead to tailored therapies via tumor-specific expression of tumoricidal proteins.

  6. Detergent-compatible bacterial amylases.

    Niyonzima, Francois N; More, Sunil S

    2014-10-01

    Proteases, lipases, amylases, and cellulases are enzymes used in detergent formulation to improve the detergency. The amylases are specifically supplemented to the detergent to digest starchy stains. Most of the solid and liquid detergents that are currently manufactured contain alkaline enzymes. The advantages of using alkaline enzymes in the detergent formulation are that they aid in removing tough stains and the process is environmentally friendly since they reduce the use of toxic detergent ingredients. Amylases active at low temperature are preferred as the energy consumption gets reduced, and the whole process becomes cost-effective. Most microbial alkaline amylases are used as detergent ingredients. Various reviews report on the production, purification, characterization, and application of amylases in different industry sectors, but there is no specific review on bacterial or fungal alkaline amylases or detergent-compatible amylases. In this mini-review, an overview on the production and property studies of the detergent bacterial amylases is given, and the stability and compatibility of the alkaline bacterial amylases in the presence of the detergents and the detergent components are highlighted.

  7. On reconstruction of an unknown polygonal cavity in a linearized elasticity with one measurement

    Ikehata, M; Itou, H

    2011-01-01

    In this paper we consider a reconstruction problem of an unknown polygonal cavity in a linearized elastic body. For this problem, an extraction formula of the convex hull of the unknown polygonal cavity is established by means of the enclosure method introduced by Ikehata. The advantages of our method are that it needs only a single set of boundary data and we do not require any a priori assumptions for the unknown polygonal cavity and any constraints on boundary data. The theoretical formula may have possibility of application in nondestructive evaluation.

  8. Row Reduced Echelon Form for Solving Fully Fuzzy System with Unknown Coefficients

    Ghassan Malkawi

    2014-08-01

    Full Text Available This study proposes a new method for finding a feasible fuzzy solution in positive Fully Fuzzy Linear System (FFLS, where the coefficients are unknown. The fully fuzzy system is transferred to linear system in order to obtain the solution using row reduced echelon form, thereafter; the crisp solution is restricted in obtaining the positive fuzzy solution. The fuzzy solution of FFLS is included crisp intervals, to assign alternative values of unknown entries of fuzzy numbers. To illustrate the proposed method, numerical examples are solved, where the entries of coefficients are unknown in right or left hand side, to demonstrate the contributions in this study.

  9. Infections associated with body modification

    Samson Sai-Yin Wong

    2012-12-01

    Full Text Available Although exact statistics are lacking, body modifications for cosmetic purposes are performed in many countries. The commonest forms include tattooing, body piercing, and breast and facial augmentation using implants or injectable fillers. Liposuction and, to a lesser extent, mesotherapy are also practiced in many countries. Infective complications of these procedures include local infections, transmission of bloodborne pathogens (viral hepatitis and human immunodeficiency virus, and distant infections such as infective endocarditis. Presence of foreign bodies, long healing time of piercing wounds, and poor compliance with infection control practices of some practitioners all predispose the recipients to infections. Apart from the endogenous microbial flora of the skin and mucosae, atypical mycobacteria, especially the rapid growers, have emerged as some of the most important pathogens in such settings. Outbreaks of infection are commonly reported. We hereby review the current knowledge of the topic with specific focus on infections associated with tattooing, body piercing, breast augmentation, mesotherapy, liposuction, and tissue filler injections. Greater awareness among consumers and health-care professionals, as well as more stringent regulations by the health authorities, is essential to minimize the health risks arising from these procedures.

  10. Regulating the unknown: Managing the occupational health risks of nanomedical technologies and nanopharmaceuticals in the research laboratory

    Ersin, Ozlem Hacer

    Novel technologies and their resultant products demand fresh ways of thinking about pre-market risk analysis and post-market surveillance. A regulatory framework that is responsive to emerging knowledge about the hazards of novel technologies offers repeatable and transparent processes and remains economically and socially feasible. Workers are an especially vulnerable population who are exposed to unknown hazards of novel technologies and serve often as unwitting sentinels of impending risks. This Grounded Theory-based case study identifies gaps in our current ability to regulate novel technologies so as to minimize occupational health risks and offers necessary modifications for an environment that is conducive to proper regulation. Nanopharmaceuticals and the nano-based technologies at their base are used by way of exemplar technologies that are currently taxing the ability of the regulatory system to provide adequate oversight. Ambiguities of definition, absence of a tracking system (of who is doing nanotechnology research), and the paucity of scientific evidence to support risk management efforts are among the findings of the study and need to be addressed as ameliorative steps toward an effective regulatory structure.

  11. Anode modification with formic acid: A simple and effective method to improve the power generation of microbial fuel cells

    Liu, Weifeng; Cheng, Shaoan, E-mail: shaoancheng@zju.edu.cn; Guo, Jian

    2014-11-30

    Highlights: • Carbon cloth anode is modified with formic acid by a simple and reliable approach. • The modification significantly enhances the power output of microbial fuel cells. • The modified anode surface favors the bacterial attachment and growth on anode. • The electron transfer rate of anode is promoted. - Abstract: The physicochemical properties of anode material directly affect the anodic biofilm formation and electron transfer, thus are critical for the power generation of microbial fuel cells (MFCs). In this work, carbon cloth anode was modified with formic acid to enhance the power production of MFCs. Formic acid modification of anode increased the maximum power density of a single-chamber air-cathode MFC by 38.1% (from 611.5 ± 6 mW/m{sup 2} to 877.9 ± 5 mW/m{sup 2}). The modification generated a cleaner electrode surface and a reduced content of oxygen and nitrogen groups on the anode. The surface changes facilitated bacterial growth on the anode and resulted in an optimized microbial community. Thus, the electron transfer rate on the modified anodes was enhanced remarkably, contributing to a higher power output of MFCs. Anode modification with formic acid could be an effective and simple method for improving the power generation of MFCs. The modification method holds a huge potential for large scale applications and is valuable for the scale-up and commercialization of microbial fuel cells.

  12. Quality planning for major plant design modifications

    Dulee, R.J.

    1988-01-01

    This paper reviews the approach and activities undertaken by Public Service Electric and Gas Company's (PSE and G's) nuclear quality assurance (QA) department to support major plant design modifications conducted during refueling outages at Salem Generating Station. It includes the planning and implementation of quality plans developed to provide both QA and quality control (QC) coverage of modification performed by contracted service organizations

  13. Modification of the perturbative QCD towards confinement

    Arodz, H.

    1981-01-01

    Modification of the low momentum behaviour of the perturbative SU(2) gauge theory is proposed. The modification is closely related (although not equivalent) to a nonstandard choice of boundary condition for the Euclidean 2-point gluonic Green function. In the resulting theory already single graphs lead to the confining potential between heavy, static quarks, V(r) = ar 2 for r → infinity. (author)

  14. 75 FR 41529 - Petitions for Modification

    2010-07-16

    ... application of existing mandatory safety standards published in Title 30 of the Code of Federal Regulations... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

  15. 75 FR 29784 - Petitions for Modification

    2010-05-27

    ... application of existing mandatory safety standards published in Title 30 of the Code of Federal Regulations... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

  16. 75 FR 34486 - Petitions for Modification

    2010-06-17

    ... application of existing mandatory safety standards published in Title 30 of the Code of Federal Regulations... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

  17. Engineering specific chemical modification sites into a collagen-like protein from Streptococcus pyogenes.

    Stoichevska, Violet; Peng, Yong Y; Vashi, Aditya V; Werkmeister, Jerome A; Dumsday, Geoff J; Ramshaw, John A M

    2017-03-01

    Recombinant bacterial collagens provide a new opportunity for safe biomedical materials. They are readily expressed in Escherichia coli in good yield and can be readily purified by simple approaches. However, recombinant proteins are limited in that direct secondary modification during expression is generally not easily achieved. Thus, inclusion of unusual amino acids, cyclic peptides, sugars, lipids, and other complex functions generally needs to be achieved chemically after synthesis and extraction. In the present study, we have illustrated that bacterial collagens that have had their sequences modified to include cysteine residue(s), which are not normally present in bacterial collagen-like sequences, enable a range of specific chemical modification reactions to be produced. Various model reactions were shown to be effective for modifying the collagens. The ability to include alkyne (or azide) functions allows the extensive range of substitutions that are available via "click" chemistry to be accessed. When bifunctional reagents were used, some crosslinking occurred to give higher molecular weight polymeric proteins, but gels were not formed. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 806-813, 2017. © 2016 Wiley Periodicals, Inc.

  18. Identification of 8-methyladenosine as the modification catalyzed by the radical SAM methyltransferase Cfr that confers antibiotic resistance in bacteria

    Giessing, Anders; Jensen, Søren Skov; Rasmussen, Anette

    2009-01-01

    The Cfr methyltransferase confers combined resistance to five different classes of antibiotics that bind to the peptidyl transferase center of bacterial ribosomes. The Cfr-mediated modification has previously been shown to occur on nucleotide A2503 of 23S rRNA and has a mass corresponding......,8-dimethyladenosine. The mutation of single conserved cysteine residues in the radical SAM motif CxxxCxxC of Cfr abolishes its activity, lending support to the notion that the Cfr modification reaction occurs via a radical-based mechanism. Antibiotic susceptibility data confirm that the antibiotic resistance...

  19. Modification Semantics in Now-Relative Databases

    Torp, Kristian; Jensen, Christian Søndergaard; Snodgrass, R. T.

    2004-01-01

    Most real-world databases record time-varying information. In such databases, the notion of ??the current time,?? or NOW, occurs naturally and prominently. For example, when capturing the past states of a relation using begin and end time columns, tuples that are part of the current state have some...... past time as their begin time and NOW as their end time. While the semantics of such variable databases has been described in detail and is well understood, the modification of variable databases remains unexplored. This paper defines the semantics of modifications involving the variable NOW. More...... specifically,  the problems with modifications in the presence of NOW are explored, illustrating that the main problems are with modifications of tuples that reach into the future. The paper defines the semantics of modifications?including insertions, deletions, and updates?of databases without NOW, with NOW...

  20. Methodological guidelines for developing accident modification functions

    Elvik, Rune

    2015-01-01

    This paper proposes methodological guidelines for developing accident modification functions. An accident modification function is a mathematical function describing systematic variation in the effects of road safety measures. The paper describes ten guidelines. An example is given of how to use...... limitations in developing accident modification functions are the small number of good evaluation studies and the often huge variation in estimates of effect. It is therefore still not possible to develop accident modification functions for very many road safety measures. © 2015 Elsevier Ltd. All rights...... the guidelines. The importance of exploratory analysis and an iterative approach in developing accident modification functions is stressed. The example shows that strict compliance with all the guidelines may be difficult, but represents a level of stringency that should be strived for. Currently the main...

  1. Application of radiation technology in starch modification

    Chen Huiyuan; Peng Zhigang; Ding Zhongmin; Lu Jiajiu

    2007-01-01

    In order to commercialize the radiation modification of starch, corn starch was irradiated with different dose of 60 Co gamma radiations. Some basic physical and chemical properties of the resulted modified starch paste were measured with emphasis on the viscosity stability and tensile strength. The results indicate that irradiation of corn starch with a dose of 4-10 kGy can decrease its viscosity to 5-14 mPa·s, and the tensile strength can meet the standard set up for textile paste. In comparison with chemical modification for starch, radiation modification is simpler in technology, more convenient in operation, more stable in modification quality, and easier to control. The mechanism of radiation modification of starch was also discussed. (authors)

  2. WATER TEMPERATURE and Other Data from UNKNOWN from 19630301 to 19650331 (NODC Accession 9500033)

    National Oceanic and Atmospheric Administration, Department of Commerce — The chorophyll data set was collected from unknown platforms. Data was collected over two year period spanning from March 1, 1963 to March 31, 1965. The data...

  3. Speeding up transmissions of unknown quantum information along Ising-type quantum channels

    Guo W J; Wei L F

    2017-01-01

    Quantum teleportation with entanglement channels and a series of two-qubit SWAP gates between the nearest-neighbor qubits are usually utilized to achieve the transfers of unknown quantum state from the sender to the distant receiver. In this paper, by simplifying the usual SWAP gates we propose an approach to speed up the transmissions of unknown quantum information, specifically including the single-qubit unknown state and two-qubit unknown entangled ones, by a series of entangling and disentangling operations between the remote qubits with distant interactions. The generic proposal is demonstrated specifically with experimentally-existing Ising-type quantum channels without transverse interaction; liquid NMR-molecules driven by global radio frequency electromagnetic pulses and capacitively-coupled Josephson circuits driven by local microwave pulses. The proposal should be particularly useful to set up the connections between the distant qubits in a chip of quantum computing. (paper)

  4. Rendezvous with connectivity preservation for multi-robot systems with an unknown leader

    Dong, Yi

    2018-02-01

    This paper studies the leader-following rendezvous problem with connectivity preservation for multi-agent systems composed of uncertain multi-robot systems subject to external disturbances and an unknown leader, both of which are generated by a so-called exosystem with parametric uncertainty. By combining internal model design, potential function technique and adaptive control, two distributed control strategies are proposed to maintain the connectivity of the communication network, to achieve the asymptotic tracking of all the followers to the output of the unknown leader system, as well as to reject unknown external disturbances. It is also worth to mention that the uncertain parameters in the multi-robot systems and exosystem are further allowed to belong to unknown and unbounded sets when applying the second fully distributed control law containing a dynamic gain inspired by high-gain adaptive control or self-tuning regulator.

  5. Matrix- and tensor-based recommender systems for the discovery of currently unknown inorganic compounds

    Seko, Atsuto; Hayashi, Hiroyuki; Kashima, Hisashi; Tanaka, Isao

    2018-01-01

    Chemically relevant compositions (CRCs) and atomic arrangements of inorganic compounds have been collected as inorganic crystal structure databases. Machine learning is a unique approach to search for currently unknown CRCs from vast candidates. Herein we propose matrix- and tensor-based recommender system approaches to predict currently unknown CRCs from database entries of CRCs. Firstly, the performance of the recommender system approaches to discover currently unknown CRCs is examined. A Tucker decomposition recommender system shows the best discovery rate of CRCs as the majority of the top 100 recommended ternary and quaternary compositions correspond to CRCs. Secondly, systematic density functional theory (DFT) calculations are performed to investigate the phase stability of the recommended compositions. The phase stability of the 27 compositions reveals that 23 currently unknown compounds are newly found to be stable. These results indicate that the recommender system has great potential to accelerate the discovery of new compounds.

  6. Robust adaptive fuzzy neural tracking control for a class of unknown ...

    In this paper, an adaptive fuzzy neural controller (AFNC) for a class of unknown chaotic systems is ... The robust controller is used to guarantee the stability and to control the per- ..... From the above analysis we have the following theorem:.

  7. Chaos Synchronization Based on Unknown Input Proportional Multiple-Integral Fuzzy Observer

    T. Youssef

    2013-01-01

    Full Text Available This paper presents an unknown input Proportional Multiple-Integral Observer (PIO for synchronization of chaotic systems based on Takagi-Sugeno (TS fuzzy chaotic models subject to unmeasurable decision variables and unknown input. In a secure communication configuration, this unknown input is regarded as a message encoded in the chaotic system and recovered by the proposed PIO. Both states and outputs of the fuzzy chaotic models are subject to polynomial unknown input with kth derivative zero. Using Lyapunov stability theory, sufficient design conditions for synchronization are proposed. The PIO gains matrices are obtained by resolving linear matrix inequalities (LMIs constraints. Simulation results show through two TS fuzzy chaotic models the validity of the proposed method.

  8. Design of a DNA chip for detection of unknown genetically modified organisms (GMOs).

    Nesvold, Håvard; Kristoffersen, Anja Bråthen; Holst-Jensen, Arne; Berdal, Knut G

    2005-05-01

    Unknown genetically modified organisms (GMOs) have not undergone a risk evaluation, and hence might pose a danger to health and environment. There are, today, no methods for detecting unknown GMOs. In this paper we propose a novel method intended as a first step in an approach for detecting unknown genetically modified (GM) material in a single plant. A model is designed where biological and combinatorial reduction rules are applied to a set of DNA chip probes containing all possible sequences of uniform length n, creating probes capable of detecting unknown GMOs. The model is theoretically tested for Arabidopsis thaliana Columbia, and the probabilities for detecting inserts and receiving false positives are assessed for various parameters for this organism. From a theoretical standpoint, the model looks very promising but should be tested further in the laboratory. The model and algorithms will be available upon request to the corresponding author.

  9. Decentralised output feedback control of Markovian jump interconnected systems with unknown interconnections

    Li, Li-Wei; Yang, Guang-Hong

    2017-07-01

    The problem of decentralised output feedback control is addressed for Markovian jump interconnected systems with unknown interconnections and general transition rates (TRs) allowed to be unknown or known with uncertainties. A class of decentralised dynamic output feedback controllers are constructed, and a cyclic-small-gain condition is exploited to dispose the unknown interconnections so that the resultant closed-loop system is stochastically stable and satisfies an H∞ performance. With slack matrices to cope with the nonlinearities incurred by unknown and uncertain TRs in control synthesis, a novel controller design condition is developed in linear matrix inequality formalism. Compared with the existing works, the proposed approach leads to less conservatism. Finally, two examples are used to illustrate the effectiveness of the new results.

  10. Robust Control for the Segway with Unknown Control Coefficient and Model Uncertainties

    Byung Woo Kim

    2016-06-01

    Full Text Available The Segway, which is a popular vehicle nowadays, is an uncertain nonlinear system and has an unknown time-varying control coefficient. Thus, we should consider the unknown time-varying control coefficient and model uncertainties to design the controller. Motivated by this observation, we propose a robust control for the Segway with unknown control coefficient and model uncertainties. To deal with the time-varying unknown control coefficient, we employ the Nussbaum gain technique. We introduce an auxiliary variable to solve the underactuated problem. Due to the prescribed performance control technique, the proposed controller does not require the adaptive technique, neural network, and fuzzy logic to compensate the uncertainties. Therefore, it can be simple. From the Lyapunov stability theory, we prove that all signals in the closed-loop system are bounded. Finally, we provide the simulation results to demonstrate the effectiveness of the proposed control scheme.

  11. Problems of determination of principle of psychological profile of unknown criminal person in investigational activity

    Galina Getman

    2017-03-01

    By the author of the article of analysis different determinations of «psychological profile of unknown criminal person» were subjected. They are set positive lines and separate positions that in opinion of author are not expedient and important are subjected to criticism. That is why, the author points in conclusions the argued positions in relation to the necessity of the use of psychological profile of  unknown criminal person during investigation of criminal realizations in activity of investigator.

  12. High Precision Fast Projective Synchronization for Chaotic Systems with Unknown Parameters

    Nian, Fuzhong; Wang, Xingyuan; Lin, Da; Niu, Yujun

    2013-08-01

    A high precision fast projective synchronization method for chaotic systems with unknown parameters was proposed by introducing optimal matrix. Numerical simulations indicate that the precision be improved about three orders compared with other common methods under the same condition of software and hardware. Moreover, when average error is less than 10-3, the synchronization speed is 6500 times than common methods, the iteration needs only 4 times. The unknown parameters also were identified rapidly. The theoretical analysis and proof also were given.

  13. Extensive screening for primary tumor is redundant in melanoma of unknown primary

    Tos, Tina; Klyver, Helle; Drzewiecki, Krzysztof T

    2011-01-01

    For decades, patients in our institution with metastastic melanoma of unknown primary have been subjected to extensive examinations in search of the primary tumor. This retrospective study questions the results, and thus the feasibility of these examinations. Of 103 patients diagnosed with unknow......, for patients referred with metastastic melanoma of unknown primary, we recommend that a detailed history is obtained, and a standard physical examination performed, in addition to a histopathological review and CT/PET for staging....

  14. Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

    Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

    2017-05-24

    In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

  15. Eddy current analysis by BEM utilizing loop electric and surface magnetic currents as unknowns

    Ishibashi, Kazuhisa

    2002-01-01

    The surface integral equations whose unknowns are the surface electric and magnetic currents are widely used in eddy current analysis. However, when the skin depth is thick, computational error is increased especially in obtaining electromagnetic fields near the edge of the conductor. In order to obtain the electromagnetic field accurately, we propose an approach to solve surface integral equations utilizing loop electric and surface magnetic currents as unknowns. (Author)

  16. M-MRAC Backstepping for Systems with Unknown Virtual Control Coefficients

    Stepanyan, Vahram; Krishnakumar, Kalmanje

    2015-01-01

    The paper presents an over-parametrization free certainty equivalence state feedback backstepping adaptive control design method for systems of any relative degree with unmatched uncertainties and unknown virtual control coefficients. It uses a fast prediction model to estimate the unknown parameters, which is independent of the control design. It is shown that the system's input and output tracking errors can be systematically decreased by the proper choice of the design parameters. The benefits of the approach are demonstrated in numerical simulations.

  17. Effect of temperature, pH and detergents on the antifungal activity of bacterial culture filtrates against Mycosphaerella fijiensis

    Eilyn Mena

    2014-01-01

    Full Text Available The bacteria associated to crops have been studied as potential biocontrol agents. However, few investigations on the interaction Musa spp. - Mycosphaerella fijiensis-Musa associated bacteria have been developed. Consequently, bacterial metabolites involved and the effect on them of physical and chemical factors remain unknown. Therefore, this study aimed to determine the effect of temperature, pH and detergents on bacterial culture filtrates with antifungal activity in vitro against Mycosphaerella fijiensis. The pathogen growth inhibition was assessed by absorbance reading at OD 565nm. It was found that the antifungal activity of the bacterial culture filtrates against M. fijiensis, varied in the presence of different values of temperature, pH, and types of detergents and this was related to the bacterial strain. The results suggested the possible protein nature of the metabolites with antifungal activity. Keywords: bacteria, biological control, antifungal metabolites

  18. Quantum jointly assisted cloning of an unknown three-dimensional equatorial state

    Ma, Peng-Cheng; Chen, Gui-Bin; Li, Xiao-Wei; Zhan, You-Bang

    2018-02-01

    We present two schemes for perfectly cloning an unknown single-qutrit equatorial state with assistance from two and N state preparers, respectively. In the first scheme, the sender wishes to teleport an unknown single-qutrit equatorial state from two state preparers to a remote receiver, and then to create a perfect copy of the unknown state at her location. The scheme consists of two stages. The first stage of the scheme requires the usual teleportation. In the second stage, to help the sender realize the quantum cloning, two state preparers perform single-qutrit projective measurements on their own qutrits from the sender, then the sender can acquire a perfect copy of the unknown state. It is shown that, only if the two state preparers collaborate with each other, the sender can create a copy of the unknown state by means of some appropriate unitary operations. In the second scheme, we generalized the jointly assisted cloning in the first scheme to the case of N state prepares. In the present schemes, the total probability of success for assisted cloning of a perfect copy of the unknown state can reach 1.

  19. Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

    Oliveira, Rafael L. de; Barud, Hernane; Ribeiro, Sidney J.L.; Messaddeq, Younes

    2011-01-01

    The chemical modification of cellulose leads to production of derivatives with different properties from those observed for the original cellulose, for example, increased solubility in more traditional solvents. In this work we synthesized four derivatives of cellulose: microcrystalline cellulose, cellulose acetate, methylcellulose and carboxymethylcellulose using bacterial cellulose as a source. These were characterized in terms of chemical and structural changes by examining the degree of substitution (DS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy - NMR 13 C. The molecular weight and degree of polymerization were evaluated by viscometry. The characterization of the morphology of materials and thermal properties were performed with the techniques of X-ray diffraction, electron microscopy images, differential scanning calorimetry (DSC) and thermogravimetric analysis. (author)

  20. High resolution imaging of surface patterns of single bacterial cells

    Greif, Dominik; Wesner, Daniel; Regtmeier, Jan; Anselmetti, Dario

    2010-01-01

    We systematically studied the origin of surface patterns observed on single Sinorhizobium meliloti bacterial cells by comparing the complementary techniques atomic force microscopy (AFM) and scanning electron microscopy (SEM). Conditions ranged from living bacteria in liquid to fixed bacteria in high vacuum. Stepwise, we applied different sample modifications (fixation, drying, metal coating, etc.) and characterized the observed surface patterns. A detailed analysis revealed that the surface structure with wrinkled protrusions in SEM images were not generated de novo but most likely evolved from similar and naturally present structures on the surface of living bacteria. The influence of osmotic stress to the surface structure of living cells was evaluated and also the contribution of exopolysaccharide and lipopolysaccharide (LPS) by imaging two mutant strains of the bacterium under native conditions. AFM images of living bacteria in culture medium exhibited surface structures of the size of single proteins emphasizing the usefulness of AFM for high resolution cell imaging.

  1. Modifications to the INSPECT model

    Dickinson, S [AEA Technology, Winfrith (United Kingdom); Sims, H E [AEA Technology, Harwell (United Kingdom)

    1996-12-01

    The prediction of iodine behaviour in the containment of a PWR following a loss of coolant accident requires a reliable model of the chemistry of iodine in aqueous solution. The INSPECT model, which was developed several years ago, contains a large number of the relevant chemical reactions of iodine and water radiation chemistry. Since the reactions set was first assembled, however, new data on rate constants and mechanisms have become available. In addition, the application of the model to various small-scale experiments has revealed problems in the modelling of some reactions, leading to an under-prediction of the iodine volatility at high pH, although the experiments have demonstrated that the high pH volatility remains satisfactory low. This paper describes the modifications which have been made to the INSPECT model to take account of new data and to improve the modelling where appropriate. The main changes which have been made to the reaction set are as follows: - The rate constants and activation energies for the reactions describing the radiolysis of water have been updated in with recent assessments, and the temperature dependence of the G value for the primary species have been accordance taken into account, - The mechanism and rates of I{sub 2} hydrolysis have been modified in accordance with the latest assessments of this reaction, - The mechanism for the reaction of I{sub 2} with H{sub 2}O{sub 2} has been changed to a form which produces a more realistic pH dependence under neutral and alkaline conditions, - An addition mechanism for the disproportionation of the O{sub 2} ion has been included, reflecting experimental observations that this reaction has a significant first-order component under all but the purest conditions, - Atomic I is treated as a volatile species, with a partition coefficient of 1.9 at 298 K. (Abstract Truncated)

  2. Surface modifications of dental implants.

    Stanford, C M

    2008-06-01

    Dental implant surface technologies have been evolving rapidly to enhance a more rapid bone formation on their surface and hold a potential to increase the predictability of expedited implant therapy. While implant outcomes have become highly predictable, there are sites and conditions that result in elevated implant loss. This paper reviews the impact of macro-retentive features which includes approaches to surface oxide modification, thread design, press-fit and sintered-bead technologies to increase predictability of outcomes. Implant designs that lead to controlled lateral compression of the bone can improve primary stability as long as the stress does not exceed the localized yield strength of the cortical bone. Some implant designs have reduced crestal bone loss by use of multiple cutting threads that are closely spaced, smoothed on the tip but designed to create a hoop-stress stability of the implant as it is completely seated in the osteotomy. Following the placement of the implant, there is a predictable sequence of bone turnover and replacement at the interface that allows the newly formed bone to adapt to microscopic roughness on the implant surface, and on some surfaces, a nanotopography (<10(-9) m scale) that has been shown to preferably influence the formation of bone. Newly emerging studies show that bone cells are exquisitely sensitive to these topographical features and will upregulate the expression of bone related genes for new bone formation when grown on these surfaces. We live in an exciting time of rapid changes in the modalities we can offer patients for tooth replacement therapy. Given this, it is our responsibility to be critical when claims are made, incorporate into our practice what is proven and worthwhile, and to continue to support and provide the best patient care possible.

  3. BACTERIA - BACTERIAL DENSITY, SALINITY and other data from UNKNOWN PLATFORMS in the NW Pacific from 1989-10-16 to 1990-07-07 (NODC Accession 9200078)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession was collected in NW Pacific (limit-180) as part of Tropical Ocean Global Atmosphere (TOGA). The marine biochemistry and bathythermograph...

  4. Homogenizing bacterial cell factories: Analysis and engineering of phenotypic heterogeneity.

    Binder, Dennis; Drepper, Thomas; Jaeger, Karl-Erich; Delvigne, Frank; Wiechert, Wolfgang; Kohlheyer, Dietrich; Grünberger, Alexander

    2017-07-01

    In natural habitats, microbes form multispecies communities that commonly face rapidly changing and highly competitive environments. Thus, phenotypic heterogeneity has evolved as an innate and important survival strategy to gain an overall fitness advantage over cohabiting competitors. However, in defined artificial environments such as monocultures in small- to large-scale bioreactors, cell-to-cell variations are presumed to cause reduced production yields as well as process instability. Hence, engineering microbial production toward phenotypic homogeneity is a highly promising approach for synthetic biology and bioprocess optimization. In this review, we discuss recent studies that have unraveled the cell-to-cell heterogeneity observed during bacterial gene expression and metabolite production as well as the molecular mechanisms involved. In addition, current single-cell technologies are briefly reviewed with respect to their applicability in exploring cell-to-cell variations. We highlight emerging strategies and tools to reduce phenotypic heterogeneity in biotechnological expression setups. Here, strain or inducer modifications are combined with cell physiology manipulations to achieve the ultimate goal of equalizing bacterial populations. In this way, the majority of cells can be forced into high productivity, thus reducing less productive subpopulations that tend to consume valuable resources during production. Modifications in uptake systems, inducer molecules or nutrients represent valuable tools for diminishing heterogeneity. Finally, we address the challenge of transferring homogeneously responding cells into large-scale bioprocesses. Environmental heterogeneity originating from extrinsic factors such as stirring speed and pH, oxygen, temperature or nutrient distribution can significantly influence cellular physiology. We conclude that engineering microbial populations toward phenotypic homogeneity is an increasingly important task to take biotechnological

  5. Functional microdomains in bacterial membranes.

    López, Daniel; Kolter, Roberto

    2010-09-01

    The membranes of eukaryotic cells harbor microdomains known as lipid rafts that contain a variety of signaling and transport proteins. Here we show that bacterial membranes contain microdomains functionally similar to those of eukaryotic cells. These membrane microdomains from diverse bacteria harbor homologs of Flotillin-1, a eukaryotic protein found exclusively in lipid rafts, along with proteins involved in signaling and transport. Inhibition of lipid raft formation through the action of zaragozic acid--a known inhibitor of squalene synthases--impaired biofilm formation and protein secretion but not cell viability. The orchestration of physiological processes in microdomains may be a more widespread feature of membranes than previously appreciated.

  6. Automated pathway and reaction prediction facilitates in silico identification of unknown metabolites in human cohort studies.

    Quell, Jan D; Römisch-Margl, Werner; Colombo, Marco; Krumsiek, Jan; Evans, Anne M; Mohney, Robert; Salomaa, Veikko; de Faire, Ulf; Groop, Leif C; Agakov, Felix; Looker, Helen C; McKeigue, Paul; Colhoun, Helen M; Kastenmüller, Gabi

    2017-12-15

    Identification of metabolites in non-targeted metabolomics continues to be a bottleneck in metabolomics studies in large human cohorts. Unidentified metabolites frequently emerge in the results of association studies linking metabolite levels to, for example, clinical phenotypes. For further analyses these unknown metabolites must be identified. Current approaches utilize chemical information, such as spectral details and fragmentation characteristics to determine components of unknown metabolites. Here, we propose a systems biology model exploiting the internal correlation structure of metabolite levels in combination with existing biochemical and genetic information to characterize properties of unknown molecules. Levels of 758 metabolites (439 known, 319 unknown) in human blood samples of 2279 subjects were measured using a non-targeted metabolomics platform (LC-MS and GC-MS). We reconstructed the structure of biochemical pathways that are imprinted in these metabolomics data by building an empirical network model based on 1040 significant partial correlations between metabolites. We further added associations of these metabolites to 134 genes from genome-wide association studies as well as reactions and functional relations to genes from the public database Recon 2 to the network model. From the local neighborhood in the network, we were able to predict the pathway annotation of 180 unknown metabolites. Furthermore, we classified 100 pairs of known and unknown and 45 pairs of unknown metabolites to 21 types of reactions based on their mass differences. As a proof of concept, we then looked further into the special case of predicted dehydrogenation reactions leading us to the selection of 39 candidate molecules for 5 unknown metabolites. Finally, we could verify 2 of those candidates by applying LC-MS analyses of commercially available candidate substances. The formerly unknown metabolites X-13891 and X-13069 were shown to be 2-dodecendioic acid and 9

  7. Modification of Sr on 4004 Aluminum Alloy

    Guo, Erjun; Cao, Guojian; Feng, Yicheng; Wang, Liping; Wang, Guojun; Lv, Xinyu

    2013-05-01

    As a brazing foil, 4004 Al alloy has good welding performance. However, the high Si content decreases the plasticity of the alloy. To improve the plasticity of 4004 Al alloy and subsequently improve the productivity of 4004 Al foil or 434 composite foil, 4004 Al alloy was modified by Al-10%Sr master alloy. Modification effects of an additional amount of Sr, modification temperature, and holding time on 4004 aluminum alloy were studied by orthogonal design. The results showed that the greatest impact parameter of 4004 aluminum alloy modification was the additional amount of Sr, followed by holding time and modification temperature. The optimum modification parameters obtained by orthogonal design were as follows: Sr addition of 0.04%, holding time of 60 min, and modification temperature of 760°C. The effect of Sr addition on modification was analyzed in detail based on orthogonal results. With increasing of Sr addition, elongation of 4004 alloy increased at first, and decreased after reaching the maximum value.

  8. Detection of viral sequence fragments of HIV-1 subfamilies yet unknown

    Stanke Mario

    2011-04-01

    Full Text Available Abstract Background Methods of determining whether or not any particular HIV-1 sequence stems - completely or in part - from some unknown HIV-1 subtype are important for the design of vaccines and molecular detection systems, as well as for epidemiological monitoring. Nevertheless, a single algorithm only, the Branching Index (BI, has been developed for this task so far. Moving along the genome of a query sequence in a sliding window, the BI computes a ratio quantifying how closely the query sequence clusters with a subtype clade. In its current version, however, the BI does not provide predicted boundaries of unknown fragments. Results We have developed Unknown Subtype Finder (USF, an algorithm based on a probabilistic model, which automatically determines which parts of an input sequence originate from a subtype yet unknown. The underlying model is based on a simple profile hidden Markov model (pHMM for each known subtype and an additional pHMM for an unknown subtype. The emission probabilities of the latter are estimated using the emission frequencies of the known subtypes by means of a (position-wise probabilistic model for the emergence of new subtypes. We have applied USF to SIV and HIV-1 sequences formerly classified as having emerged from an unknown subtype. Moreover, we have evaluated its performance on artificial HIV-1 recombinants and non-recombinant HIV-1 sequences. The results have been compared with the corresponding results of the BI. Conclusions Our results demonstrate that USF is suitable for detecting segments in HIV-1 sequences stemming from yet unknown subtypes. Comparing USF with the BI shows that our algorithm performs as good as the BI or better.

  9. Epigenetic Modifications: Therapeutic Potential in Cancer

    Manisha Sachan

    2015-08-01

    Full Text Available Epigenetic modifications and alterations in chromatin structure and function contribute to the cumulative changes observed as normal cells undergo malignant transformation. These modifications and enzymes (DNA methyltransferases, histone deacetylases, histone methyltransferases, and demethylases related to them have been deeply studied to develop new drugs, epigenome-targeted therapies and new diagnostic tools. Epigenetic modifiers aim to restore normal epigenetic modification patterns through the inhibition of epigenetic modifier enzymes. Four of them (azacitidine, decitabine, vorinostat and romidepsin are approved by the U.S. Food and Drug Administration. This article provides an overview about the known functional roles of epigenetic enzymes in cancer development.

  10. Osmoregulation – an important parameter of bacterial growth

    Marta Sochocka

    2011-11-01

    Full Text Available Environmental conditions such as temperature, pH, radiation and osmotic pressure are important factors limiting the growth and multiplication of bacteria. Regular structure and metabolism of bacterial cells are maintained through a stable arrangement of the water-electrolyte system, regulated by osmosis. The rapid changes caused by osmotic shock (dehydration, rehydration might lead to modifications of the phospholipid structure of the cell membrane and even cell death. Advances disturbing the osmosis, which are a natural part of living cells, may appear for example in colloid systems. The biological identification of the osmotic pressure is connected with an increase or decrease in the environmental osmotic strength of microorganisms’ habitat. Cells exposed to osmotic stress, such as an increase in osmotic pressure, initiate mechanisms of active coping with the adverse consequences of its effects. Osmoregulatory processes are designed to maintain cell turgor, hence ensuring proper conditions for bacterial growth. Osmoregulation, which consists of maintaining fluid and electrolyte balance of cells, raising concerns accumulation of specific compatible solutes (osmolytes. Osmolytes are small, soluble organic molecules with a positive influence on membrane stabilization and proteins, without disrupting cellular functions. Storage of compatible solutes takes place by synthesis or by downregulation from the medium by means of special transport systems, activated by mechanical stimuli. Knowledge of the impact of osmotic pressure on microbial cells and the regulation of its activity led to the appropriate use of bacteria in various branches of the biotechnology industry.

  11. Diameter of titanium nanotubes influences anti-bacterial efficacy

    Ercan, Batur; Taylor, Erik; Webster, Thomas J; Alpaslan, Ece

    2011-01-01

    Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

  12. Diameter of titanium nanotubes influences anti-bacterial efficacy

    Ercan, Batur; Taylor, Erik; Webster, Thomas J [School of Engineering, Brown University, Providence, RI 02917 (United States); Alpaslan, Ece, E-mail: thomas_webster@brown.edu [Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul (Turkey)

    2011-07-22

    Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

  13. Diameter of titanium nanotubes influences anti-bacterial efficacy

    Ercan, Batur; Taylor, Erik; Alpaslan, Ece; Webster, Thomas J.

    2011-07-01

    Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

  14. Bacterial community profile of contaminated soils in a typical antimony mining site.

    Wang, Ningning; Zhang, Suhuan; He, Mengchang

    2018-01-01

    The soils around the world's largest antimony mine have been contaminated by high concentrations of Sb and As, which might influence microbial diversity in the surrounding soils. The ecological effects of bioavailable Sb and As on the composition and diversity of microbial community in soils remain unknown. In this study, the relative abundance, taxonomic diversity and composition of bacterial community in soils from a typical Sb mine area, and the relationship between the bacterial community and bioavailable concentrations as well as environmental factors have been investigated comprehensively using high-throughput sequencing (HTS) and diffusive gradients in thin films (DGT). The results indicated that Proteobacteria, Acidobacteria, Chloroflexi, Bacteroidetes, Actinobacteria, Gemmatimonadetes, and Cyanobacteria were the dominant bacterial populations at phylum level in all soil samples, accounting for more than 80% of the bacteria sequenced. The abundance and diversity of bacterial community vary along a metal contamination gradient. Redundancy discriminate analysis (RDA) revealed that 74.74% of bacterial community variation in the contaminated soils was explained by six environmental factors (pH, Sb DGT , As DGT , potential ecological risk index (RI), TC, TN), among which pH, Sb DGT , and As DGT were dominant factors influencing the composition and diversity of bacteria. This study contributes to our understanding of microbial diversity in a local ecosystem and introduces the option of studying bioavailable Sb and As using DGT.

  15. Season, Irrigation, Leaf Age, and Escherichia coli Inoculation Influence the Bacterial Diversity in the Lettuce Phyllosphere

    Williams, Thomas R.; Moyne, Anne-Laure; Harris, Linda J.; Marco, Maria L.

    2013-01-01

    The developmental and temporal succession patterns and disturbance responses of phyllosphere bacterial communities are largely unknown. These factors might influence the capacity of human pathogens to persist in association with those communities on agriculturally-relevant plants. In this study, the phyllosphere microbiota was identified for Romaine lettuce plants grown in the Salinas Valley, CA, USA from four plantings performed over 2 years and including two irrigation methods and inoculations with an attenuated strain of Escherichia coli O157:H7. High-throughput DNA pyrosequencing of the V5 to V9 variable regions of bacterial 16S rRNA genes recovered in lettuce leaf washes revealed that the bacterial diversity in the phyllosphere was distinct for each field trial but was also strongly correlated with the season of planting. Firmicutes were generally most abundant in early season (June) plantings and Proteobacteria comprised the majority of bacteria recovered later in the year (August and October). Comparisons within individual field trials showed that bacterial diversity differed between sprinkler (overhead) and drip (surface) irrigated lettuce and increased over time as the plants grew. The microbiota were also distinct between control and E. coli O157:H7-inoculated plants and between E. coli O157:H7-inoculated plants with and without surviving pathogen cells. The bacterial inhabitants of the phyllosphere therefore appear to be affected by seasonal, irrigation, and biological factors in ways that are relevant for assessments of fresh produce food safety. PMID:23844230

  16. Effects of triclosan on bacterial community composition and ...

    Pharmaceuticals and personal care products, including antimicrobials, can be found at trace levels in treated wastewater effluent. Impacts of chemical contaminants on coastal aquatic microbial community structure and pathogen abundance are unknown despite the potential for selection through antimicrobial resistance. In particular, Vibrio, a marine bacterial genus that includes several human pathogens, displays resistance to the ubiquitous antimicrobial compound triclosan. Here we demonstrated through use of natural seawater microcosms that triclosan (at a concentration of ~5 ppm) can induce a significant Vibrio growth response (68–1,700 fold increases) in comparison with no treatment controls for three distinct coastal ecosystems: Looe Key Reef (Florida Keys National Marine Sanctuary), Doctors Arm Canal (Big Pine Key, FL), and Clam Bank Landing (North Inlet Estuary, Georgetown, SC). Additionally, microbial community analysis by 16 S rRNA gene sequencing for Looe Key Reef showed distinct changes in microbial community structure with exposure to 5 ppm triclosan, with increases observed in the relative abundance of Vibrionaceae (17-fold), Pseudoalteromonadaceae (65-fold), Alteromonadaceae (108-fold), Colwelliaceae (430-fold), and Oceanospirillaceae (1,494-fold). While the triclosan doses tested were above concentrations typically observed in coastal surface waters, results identify bacterial families that are potentially resistant to triclosan and/or adapted to u

  17. Microscopic Analysis of Bacterial Motility at High Pressure

    Nishiyama, Masayoshi; Sowa, Yoshiyuki

    2012-01-01

    The bacterial flagellar motor is a molecular machine that converts an ion flux to the rotation of a helical flagellar filament. Counterclockwise rotation of the filaments allows them to join in a bundle and propel the cell forward. Loss of motility can be caused by environmental factors such as temperature, pH, and solvation. Hydrostatic pressure is also a physical inhibitor of bacterial motility, but the detailed mechanism of this inhibition is still unknown. Here, we developed a high-pressure microscope that enables us to acquire high-resolution microscopic images, regardless of applied pressures. We also characterized the pressure dependence of the motility of swimming Escherichia coli cells and the rotation of single flagellar motors. The fraction and speed of swimming cells decreased with increased pressure. At 80 MPa, all cells stopped swimming and simply diffused in solution. After the release of pressure, most cells immediately recovered their initial motility. Direct observation of the motility of single flagellar motors revealed that at 80 MPa, the motors generate torque that should be sufficient to join rotating filaments in a bundle. The discrepancy in the behavior of free swimming cells and individual motors could be due to the applied pressure inhibiting the formation of rotating filament bundles that can propel the cell body in an aqueous environment. PMID:22768943

  18. Bacterial adhesion on amorphous and crystalline metal oxide coatings

    Almaguer-Flores, Argelia; Silva-Bermudez, Phaedra; Galicia, Rey; Rodil, Sandra E.

    2015-01-01

    Several studies have demonstrated the influence of surface properties (surface energy, composition and topography) of biocompatible materials on the adhesion of cells/bacteria on solid substrates; however, few have provided information about the effect of the atomic arrangement or crystallinity. Using magnetron sputtering deposition, we produced amorphous and crystalline TiO 2 and ZrO 2 coatings with controlled micro and nanoscale morphology. The effect of the structure on the physical–chemical surface properties was carefully analyzed. Then, we studied how these parameters affect the adhesion of Escherichia coli and Staphylococcus aureus. Our findings demonstrated that the nano-topography and the surface energy were significantly influenced by the coating structure. Bacterial adhesion at micro-rough (2.6 μm) surfaces was independent of the surface composition and structure, contrary to the observation in sub-micron (0.5 μm) rough surfaces, where the crystalline oxides (TiO 2 > ZrO 2 ) surfaces exhibited higher numbers of attached bacteria. Particularly, crystalline TiO 2 , which presented a predominant acidic nature, was more attractive for the adhesion of the negatively charged bacteria. The information provided by this study, where surface modifications are introduced by means of the deposition of amorphous or crystalline oxide coatings, offers a route for the rational design of implant surfaces to control or inhibit bacterial adhesion. - Highlights: • Amorphous (a) and crystalline (c) TiO 2 and ZrO 2 coatings were deposited. • The atomic ordering influences the coatings surface charge and nano-topography. • The atomic ordering modifies the bacterial adhesion for the same surface chemistry. • S. aureus adhesion was lower on a-TiO 2 and a-ZrO 2 than on their c-oxide counterpart. • E. coli adhesion on a-TiO 2 was lower than on the c-TiO 2

  19. Bacterial adhesion on amorphous and crystalline metal oxide coatings

    Almaguer-Flores, Argelia [Facultad de Odontología, División de Estudios de Posgrado e Investigación, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, 04510 México D.F. (Mexico); Silva-Bermudez, Phaedra, E-mail: suriel21@yahoo.com [Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa, Instituto Nacional de Rehabilitación, Calzada México-Xochimilco No. 289, Col. Arenal de Guadalupe, 14389 México D.F. (Mexico); Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 México D.F. (Mexico); Galicia, Rey; Rodil, Sandra E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 México D.F. (Mexico)

    2015-12-01

    Several studies have demonstrated the influence of surface properties (surface energy, composition and topography) of biocompatible materials on the adhesion of cells/bacteria on solid substrates; however, few have provided information about the effect of the atomic arrangement or crystallinity. Using magnetron sputtering deposition, we produced amorphous and crystalline TiO{sub 2} and ZrO{sub 2} coatings with controlled micro and nanoscale morphology. The effect of the structure on the physical–chemical surface properties was carefully analyzed. Then, we studied how these parameters affect the adhesion of Escherichia coli and Staphylococcus aureus. Our findings demonstrated that the nano-topography and the surface energy were significantly influenced by the coating structure. Bacterial adhesion at micro-rough (2.6 μm) surfaces was independent of the surface composition and structure, contrary to the observation in sub-micron (0.5 μm) rough surfaces, where the crystalline oxides (TiO{sub 2} > ZrO{sub 2}) surfaces exhibited higher numbers of attached bacteria. Particularly, crystalline TiO{sub 2}, which presented a predominant acidic nature, was more attractive for the adhesion of the negatively charged bacteria. The information provided by this study, where surface modifications are introduced by means of the deposition of amorphous or crystalline oxide coatings, offers a route for the rational design of implant surfaces to control or inhibit bacterial adhesion. - Highlights: • Amorphous (a) and crystalline (c) TiO{sub 2} and ZrO{sub 2} coatings were deposited. • The atomic ordering influences the coatings surface charge and nano-topography. • The atomic ordering modifies the bacterial adhesion for the same surface chemistry. • S. aureus adhesion was lower on a-TiO{sub 2} and a-ZrO{sub 2} than on their c-oxide counterpart. • E. coli adhesion on a-TiO{sub 2} was lower than on the c-TiO{sub 2}.

  20. Radiological aspects of bacterial lung abscess

    Groskin, S.A.; Panicek, D.; Ewing, D.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    Clinical, radiological, and pathological data derived from an analysis of over 70 cases of bacterial lung abscess are presented. Etiologic agents and risk factors are presented. Key radiographic findings are discussed, and those that are most useful in differentiating bacterial lung abscess from cavitated carcinoma, infected cyst, and emphysema are emphasized. Radiographic aspects of the complications of bacterial lung abscess are illustrated, and radiological approaches to their therapy are discussed

  1. Bacterial, Fungal, Parasitic, and Viral Myositis

    Crum-Cianflone, Nancy F.

    2008-01-01

    Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyo...

  2. Polymicrobial infection and bacterium-mediated epigenetic modification of DNA tumor viruses contribute to pathogenesis.

    Doolittle, J M; Webster-Cyriaque, J

    2014-04-29

    ABSTRACT The human body plays host to a wide variety of microbes, commensal and pathogenic. In addition to interacting with their host, different microbes, such as bacteria and viruses, interact with each other, sometimes in ways that exacerbate disease. In particular, gene expression of a number of viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV), is known to be regulated by epigenetic modifications induced by bacteria. These viruses establish latent infection in their host cells and can be reactivated by bacterial products. Viral reactivation has been suggested to contribute to periodontal disease and AIDS. In addition, bacterium-virus interactions may play a role in cancers, such as Kaposi's sarcoma, gastric cancer, and head and neck cancer. It is important to consider the effects of coexisting bacterial infections when studying viral diseases in vivo.

  3. Intrathecal immunoglobulin synthesis in patients with symptomatic epilepsy and epilepsy of unknown etiology ('cryptogenic').

    Fauser, S; Soellner, C; Bien, C G; Tumani, H

    2017-09-01

    To compare the frequency of intrathecal immunoglobulin (Ig) synthesis in patients with symptomatic epilepsy and epilepsy of unknown etiology ('cryptogenic'). Patients with epileptic (n = 301) and non-epileptic (n = 10) seizures were retrospectively screened for autochthonous intrathecal Ig synthesis and oligoclonal bands (OCBs) in the cerebrospinal fluid. Intrathecal IgG/OCBs were detected in 8% of patients with epilepsies of unknown etiology, 5% of patients with first seizures of unknown cause and 0-4% of patients with epilepsy due to brain tumors, cerebrovascular disease or other etiologies. Intrathecal IgG/OCBs were not seen in patients with psychogenic seizures. Identical OCBs in serum and cerebrospinal fluid were more common in all patient groups (10-40% depending on underlying etiology). Intrathecal IgG synthesis/OCBs were observed slightly more frequently in patients with 'cryptogenic' epilepsy and with first seizures of unknown etiology than in other patient groups. However, this remained an infrequent finding and thus we could not confirm humoral immunity as a leading disease mechanism in patients with epilepsy in general or with unknown etiology in particular. © 2017 EAN.

  4. Balance of bacterial species in the gut

    First page Back Continue Last page Overview Graphics. Balance of bacterial species in the gut. Protective. Lactobacillus species. Bifidobacterium species. Selected E. coli. Saccharomyces boulardii. Clostridium butyricum.

  5. Association between Gallbladder Ultrasound Findings and Bacterial Culture of Bile in 70 Cats and 202 Dogs.

    Policelli Smith, R; Gookin, J L; Smolski, W; Di Cicco, M F; Correa, M; Seiler, G S

    2017-09-01

    Bacterial cholecystitis often is diagnosed by combination of gallbladder ultrasound (US) findings and positive results of bile culture. The value of gallbladder US in determining the likelihood of bile bacterial infection in cats and dogs with suspected biliary disease is unknown. To determine the value of gallbladder US in predicting bile bacterial culture results, identify most common bacterial isolates from bile, and describe complications after cholecystocentesis in cats and dogs with suspected hepatobiliary disease. Cats (70) and dogs (202) that underwent an abdominal US and submission of bile for culture were included in the study. A cross-sectional study design was used to determine the association of gallbladder US abnormalities and the results of bile cultures, and complications of cholecystocentesis. Abnormal gallbladder US had high sensitivity (96%) but low specificity (49%) in cats with positive and negative results of bile bacterial culture, respectively. Cats with normal gallbladder US findings were unlikely to have positive bile bacterial culture (negative predictive value of 96%). Gallbladder US had lower sensitivity (81%), specificity (31%), positive predictive value (20%), and negative predictive value (88%) in dogs. The most common bacterial isolates were of enteric origin, the prevalence being higher in cats. Incidence of complications after cholecystocentesis was 3.4%. Gallbladder US has a high negative predictive value for bile culture results in cats. This modality is less predictive of infection in dogs. Percutaneous US-guided cholecystocentesis has a low complication rate. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  6. Post-Translational Modifications of TRP Channels

    Olaf Voolstra

    2014-04-01

    Full Text Available Transient receptor potential (TRP channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role.

  7. Chemical modification of flax reinforced polypropylene composites

    Jacob John, Maya

    2009-04-01

    Full Text Available This paper presents an experimental study on the static and dynamic mechanical properties of nonwoven based flax fibre reinforced polypropylene composites. The effect of zein modification on flax fibres is also reported. Flax nonwovens were treated...

  8. Modifications of the Weibull distribution: A review

    Almalki, Saad J.; Nadarajah, Saralees

    2014-01-01

    It is well known that the Weibull distribution is the most popular and the most widely used distribution in reliability and in analysis of lifetime data. Unfortunately, its hazard function cannot exhibit non-monotonic shapes like the bathtub shape or the unimodal shape. Since 1958, the Weibull distribution has been modified by many researchers to allow for non-monotonic hazard functions. This paper gives an extensive review of some discrete and continuous versions of the modifications of the Weibull distribution. - Highlights: • A comprehensive review of known discrete modifications and generalizations of the Weibull distribution. • A comprehensive review of known continuous modifications and generalizations of the Weibull distribution. • Over 110 references on modifications/generalizations of the Weibull distribution. • More than 55% of the cited references appeared in the last 5 years

  9. ENDF/B-5 modifications 1986

    McLaughlin, P.K.

    1986-05-01

    This document summarizes the modifications made to the ENDF/B-5 evaluated neutron data files in 1986. The new versions of the files are available from the IAEA Nuclear Data Section upon request, costfree, on magnetic tape. (author)

  10. The computational nature of memory modification.

    Gershman, Samuel J; Monfils, Marie-H; Norman, Kenneth A; Niv, Yael

    2017-03-15

    Retrieving a memory can modify its influence on subsequent behavior. We develop a computational theory of memory modification, according to which modification of a memory trace occurs through classical associative learning, but which memory trace is eligible for modification depends on a structure learning mechanism that discovers the units of association by segmenting the stream of experience into statistically distinct clusters (latent causes). New memories are formed when the structure learning mechanism infers that a new latent cause underlies current sensory observations. By the same token, old memories are modified when old and new sensory observations are inferred to have been generated by the same latent cause. We derive this framework from probabilistic principles, and present a computational implementation. Simulations demonstrate that our model can reproduce the major experimental findings from studies of memory modification in the Pavlovian conditioning literature.

  11. Chemical modification and characterization of quaternized polysulfones.

    Nonjola, P

    2008-12-01

    Full Text Available Synthesis and characterization of anion-exchange membranes (AEMs) using polysulfones is described. The modification process of polysulfones involves two steps: Firstly, by introducing chloromethyl groups followed by quaternization reaction...

  12. Formal Design Review Foot Clamp Modification

    OTEN, T.C.

    2000-01-01

    This report documents the Design Review performed for the foot clamp modification. The report documents the acceptability of the design, identifies the documents that were reviewed, the scope of the review and the members of the review team

  13. The computational nature of memory modification

    Gershman, Samuel J; Monfils, Marie-H; Norman, Kenneth A; Niv, Yael

    2017-01-01

    Retrieving a memory can modify its influence on subsequent behavior. We develop a computational theory of memory modification, according to which modification of a memory trace occurs through classical associative learning, but which memory trace is eligible for modification depends on a structure learning mechanism that discovers the units of association by segmenting the stream of experience into statistically distinct clusters (latent causes). New memories are formed when the structure learning mechanism infers that a new latent cause underlies current sensory observations. By the same token, old memories are modified when old and new sensory observations are inferred to have been generated by the same latent cause. We derive this framework from probabilistic principles, and present a computational implementation. Simulations demonstrate that our model can reproduce the major experimental findings from studies of memory modification in the Pavlovian conditioning literature. DOI: http://dx.doi.org/10.7554/eLife.23763.001 PMID:28294944

  14. 75 FR 3253 - Petitions for Modification

    2010-01-20

    ... face equipment; maintenance) and 30 CFR 18.35 (Portable trailing cables and cords). Modification...) Limit the speed of the machine to 10 miles per hour (MPH) by permanently blocking out any gear that...

  15. Medication for Behavior Modification in Birds

    van Zeeland, Yvonne

    2018-01-01

    The use of behavior modifying drugs may be considered in birds with behavior problems, especially those refractory to behavior modification therapy and environmental management. To accomplish behavior change, a variety of drugs can be used, including psychoactive drugs, hormones, antihistamines,

  16. Behavior of restriction–modification systems as selfish mobile elements and their impact on genome evolution

    Kobayashi, Ichizo

    2001-01-01

    Restriction–modification (RM) systems are composed of genes that encode a restriction enzyme and a modification methylase. RM systems sometimes behave as discrete units of life, like viruses and transposons. RM complexes attack invading DNA that has not been properly modified and thus may serve as a tool of defense for bacterial cells. However, any threat to their maintenance, such as a challenge by a competing genetic element (an incompatible plasmid or an allelic homologous stretch of DNA, for example) can lead to cell death through restriction breakage in the genome. This post-segregational or post-disturbance cell killing may provide the RM complexes (and any DNA linked with them) with a competitive advantage. There is evidence that they have undergone extensive horizontal transfer between genomes, as inferred from their sequence homology, codon usage bias and GC content difference. They are often linked with mobile genetic elements such as plasmids, viruses, transposons and integrons. The comparison of closely related bacterial genomes also suggests that, at times, RM genes themselves behave as mobile elements and cause genome rearrangements. Indeed some bacterial genomes that survived post-disturbance attack by an RM gene complex in the laboratory have experienced genome rearrangements. The avoidance of some restriction sites by bacterial genomes may result from selection by past restriction attacks. Both bacteriophages and bacteria also appear to use homologous recombination to cope with the selfish behavior of RM systems. RM systems compete with each other in several ways. One is competition for recognition sequences in post-segregational killing. Another is super-infection exclusion, that is, the killing of the cell carrying an RM system when it is infected with another RM system of the same regulatory specificity but of a different sequence specificity. The capacity of RM systems to act as selfish, mobile genetic elements may underlie the structure and

  17. Behavior of restriction-modification systems as selfish mobile elements and their impact on genome evolution.

    Kobayashi, I

    2001-09-15

    Restriction-modification (RM) systems are composed of genes that encode a restriction enzyme and a modification methylase. RM systems sometimes behave as discrete units of life, like viruses and transposons. RM complexes attack invading DNA that has not been properly modified and thus may serve as a tool of defense for bacterial cells. However, any threat to their maintenance, such as a challenge by a competing genetic element (an incompatible plasmid or an allelic homologous stretch of DNA, for example) can lead to cell death through restriction breakage in the genome. This post-segregational or post-disturbance cell killing may provide the RM complexes (and any DNA linked with them) with a competitive advantage. There is evidence that they have undergone extensive horizontal transfer between genomes, as inferred from their sequence homology, codon usage bias and GC content difference. They are often linked with mobile genetic elements such as plasmids, viruses, transposons and integrons. The comparison of closely related bacterial genomes also suggests that, at times, RM genes themselves behave as mobile elements and cause genome rearrangements. Indeed some bacterial genomes that survived post-disturbance attack by an RM gene complex in the laboratory have experienced genome rearrangements. The avoidance of some restriction sites by bacterial genomes may result from selection by past restriction attacks. Both bacteriophages and bacteria also appear to use homologous recombination to cope with the selfish behavior of RM systems. RM systems compete with each other in several ways. One is competition for recognition sequences in post-segregational killing. Another is super-infection exclusion, that is, the killing of the cell carrying an RM system when it is infected with another RM system of the same regulatory specificity but of a different sequence specificity. The capacity of RM systems to act as selfish, mobile genetic elements may underlie the structure and

  18. Previously unknown evolutionary groups dominate the ssDNA gokushoviruses in oxic and anoxic waters of a coastal marine environment

    Jessica M. Labonté

    2015-04-01

    Full Text Available Metagenomic studies have revealed that ssDNA phages from the family Microviridae subfamily Gokushovirinae are widespread in aquatic ecosystems. It is hypothesized that gokushoviruses occupy specialized niches, resulting in differences among genotypes traversing water column gradients. Here, we use degenerate primers that amplify a fragment of the gene encoding the major capsid protein to examine the diversity of gokushoviruses in Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island, British Columbia. Amplicon sequencing of samples from the mixed oxic surface (10 m and deeper anoxic (200 m layers indicated a diverse assemblage of gokushoviruses, with greater richness at 10 m than 200 m. A comparison of amplicon sequences with sequences selected on the basis of RFLP patterns from eight surface samples collected over a one-year period revealed that gokushovirus diversity was higher in spring and summer during stratification, and lower in fall and winter after deep-water renewal, consistent with seasonal variability within gokushovirus populations. Phylogenetic analysis of clustered amplicons revealed at least five new phylogenetic clades of previously unknown sequences, with the most abundant group associated with viruses that infect SUP05, a ubiquitous and abundant member of marine oxygen minimum zones. Our results provide persuasive evidence that, while specific gokushovirus genotypes may have a narrow host range, hosts for gokushoviruses in Saanich Inlet consist of a wide range of bacterial taxa, including SUP05, a taxonomic clade of gamma proteobacterial sulfur oxidizers. Members of SUP05 are abundant in Saanich Inlet and involved in carbon, nitrogen, and sulfur cycling along the redoxline; thus, gokushoviruses are likely important mortality agents of these bacteria and have consequent influences on biogeochemical cycling in this system.

  19. Modification of Salmonella Lipopolysaccharides Prevents the Outer Membrane Penetration of Novobiocin

    Nobre, Thatyane M.; Martynowycz, Michael W.; Andreev, Konstantin; Kuzmenko, Ivan; Nikaido, Hiroshi; Gidalevitz, David

    2015-12-01

    Small hydrophilic antibiotics traverse the outer membrane of Gram-negative bacteria through porin channels. Large lipophilic agents traverse the outer membrane through its bilayer, containing a majority of lipopolysaccharides in its outer leaflet. Genes controlled by the two-component regulatory system PhoPQ modify lipopolysaccharides. We isolate lipopolysaccharides from isogenic mutants of Salmonella sp., one lacking the modification, the other fully modified. These lipopolysaccharides were reconstituted asmonolayers at the air-water interface, and their properties, aswell as their interaction with a large lipophilic drug, novobiocin, was studied. X-ray reflectivity showed that the drug penetrated the monolayer of the unmodified lipopolysaccharides reaching the hydrophobic region,butwas prevented fromthis penetration intothemodified lipopolysaccharides.Results correlatewith behavior of bacterial cells, which become resistant to antibiotics after PhoPQ-regulated modifications. Grazing incidence x-ray diffraction showed that novobiocin produced a striking increase in crystalline coherence length, and the size of the near-crystalline domains.

  20. [Alteration of intestinal permeability: the missing link between gut microbiota modifications and inflammation in obesity?].

    Genser, Laurent; Poitou, Christine; Brot-Laroche, Édith; Rousset, Monique; Vaillant, Jean-Christophe; Clément, Karine; Thenet, Sophie; Leturque, Armelle

    2016-05-01

    The increasing incidence of obesity and associated metabolic complications is a worldwide public health issue. The role of the gut in the pathophysiology of obesity, with an important part for microbiota, is becoming obvious. In rodent models of diet-induced obesity, the modifications of gut microbiota are associated with an alteration of the intestinal permeability increasing the passage of food or bacterial antigens, which contribute to low-grade inflammation and insulin resistance. In human obesity, intestinal permeability modification, and its role in the crosstalk between gut microbiota changes and inflammation at systemic and tissular levels, are still poorly documented. Hence, further characterization of the triggering mechanisms of such inflammatory responses in obese subjects could enable the development of personalized intervention strategies that will help to reduce the risk of obesity-associated diseases. © 2016 médecine/sciences – Inserm.

  1. Enhancing the formation and shear resistance of nitrifying biofilms on membranes by surface modification

    Lackner, Susanne; Holmberg, Maria; Terada, Akihiko

    2009-01-01

    Polypropylene (PP) membranes and polyethylene (PE) surfaces were modified to enhance formation and shear resistance of nitrifying biofilms for wastewater treatment applications. A combination of plasma polymerization and wet chemistry was employed to ultimately introduce poly(ethyleneglycol) (PEG......) chains with two different functional groups (-PEG-NH2 and -PEG-CH3). Biofilm growth experiments using a mixed nitrifying bacterial culture revealed that the specific combination of PEG chains with amino groups resulted in most biofilm formation on both PP and PE samples. Detachment experiments showed...... structure might be possible explanations of the superiority of the -PEG-NH2 modification. The success of the-PEG-NH2 modification was independent of the original surface and might, therefore, be used in wastewater treatment bioreactors to improve reactor performance by making biofilm formation more stable...

  2. Covalent Surface Modifications of Carbon Nanotubes.

    Pavia Sanders, Adriana [Sandia National Lab. (SNL-CA), Livermore, CA (United States); O' Bryan, Greg [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-07-01

    A report meant to document the chemistries investigated by the author for covalent surface modification of CNTs. Oxidation, cycloaddition, and radical reactions were explored to determine their success at covalently altering the CNT surface. Characterization through infrared spectroscopy, Raman spectroscopy, and thermo gravimetric analysis was performed in order to determine the success of the chemistries employed. This report is not exhaustive and was performed for CNT surface modification exploration as it pertains to the "Next Gen" project.

  3. Zero Distribution of System with Unknown Random Variables Case Study: Avoiding Collision Path

    Parman Setyamartana

    2014-07-01

    Full Text Available This paper presents the stochastic analysis of finding the feasible trajectories of robotics arm motion at obstacle surrounding. Unknown variables are coefficients of polynomials joint angle so that the collision-free motion is achieved. ãk is matrix consisting of these unknown feasible polynomial coefficients. The pattern of feasible polynomial in the obstacle environment shows as random. This paper proposes to model the pattern of this randomness values using random polynomial with unknown variables as coefficients. The behavior of the system will be obtained from zero distribution as the characteristic of such random polynomial. Results show that the pattern of random polynomial of avoiding collision can be constructed from zero distribution. Zero distribution is like building block of the system with obstacles as uncertainty factor. By scale factor k, which has range, the random coefficient pattern can be predicted.

  4. High-order sliding mode observer for fractional commensurate linear systems with unknown input

    Belkhatir, Zehor

    2017-05-20

    In this paper, a high-order sliding mode observer (HOSMO) is proposed for the joint estimation of the pseudo-state and the unknown input of fractional commensurate linear systems with single unknown input and a single output. The convergence of the proposed observer is proved using a Lyapunov-based approach. In addition, an enhanced variant of the proposed fractional-HOSMO is introduced to avoid the peaking phenomenon and thus to improve the estimation results in the transient phase. Simulation results are provided to illustrate the performance of the proposed fractional observer in both noise-free and noisy cases. The effect of the observer’s gains on the estimated pseudo-state and unknown input is also discussed.

  5. Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction.

    Boiteau, Rene M; Hoyt, David W; Nicora, Carrie D; Kinmonth-Schultz, Hannah A; Ward, Joy K; Bingol, Kerem

    2018-01-17

    We introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS²), and NMR into a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter out the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture, and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana . The NMR/MS² approach is well suited to the discovery of new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases.

  6. Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots with Unknown Sliding

    Mingyue Cui

    2012-11-01

    Full Text Available An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time-varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunov-stability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed-loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.

  7. 18F-FDG-PET/CT in fever of unknown origin

    Middelbo Buch-Olsen, Karen; Andersen, Rikke V; Hess, Søren

    2014-01-01

    OBJECTIVE: Fever of unknown origin continues to be a diagnostic challenge for clinicians. The aim of this study was to confirm whether (18)F-fluorodeoxyglucose ((18)F-FDG)-PET/computed tomography (CT) is a helpful tool in patients suffering from this condition. PATIENTS AND METHODS: Fifty......-seven patients with fever of unknown origin were examined with (18)F-FDG-PET/CT as part of their diagnostic workup at the clinicians' discretion. The medical records were read retrospectively to establish the final diagnosis and evaluate the degree to which PET/CT contributed to the diagnosis. RESULTS......-FDG-PET/CT is a useful tool in the investigation of fever of unknown origin; it can reduce patient inconvenience and possibly costs to society if used earlier in the diagnostic process....

  8. High-order sliding mode observer for fractional commensurate linear systems with unknown input

    Belkhatir, Zehor; Laleg-Kirati, Taous-Meriem

    2017-01-01

    In this paper, a high-order sliding mode observer (HOSMO) is proposed for the joint estimation of the pseudo-state and the unknown input of fractional commensurate linear systems with single unknown input and a single output. The convergence of the proposed observer is proved using a Lyapunov-based approach. In addition, an enhanced variant of the proposed fractional-HOSMO is introduced to avoid the peaking phenomenon and thus to improve the estimation results in the transient phase. Simulation results are provided to illustrate the performance of the proposed fractional observer in both noise-free and noisy cases. The effect of the observer’s gains on the estimated pseudo-state and unknown input is also discussed.

  9. Circuit realization, chaos synchronization and estimation of parameters of a hyperchaotic system with unknown parameters

    A. Elsonbaty

    2014-10-01

    Full Text Available In this article, the adaptive chaos synchronization technique is implemented by an electronic circuit and applied to the hyperchaotic system proposed by Chen et al. We consider the more realistic and practical case where all the parameters of the master system are unknowns. We propose and implement an electronic circuit that performs the estimation of the unknown parameters and the updating of the parameters of the slave system automatically, and hence it achieves the synchronization. To the best of our knowledge, this is the first attempt to implement a circuit that estimates the values of the unknown parameters of chaotic system and achieves synchronization. The proposed circuit has a variety of suitable real applications related to chaos encryption and cryptography. The outputs of the implemented circuits and numerical simulation results are shown to view the performance of the synchronized system and the proposed circuit.

  10. Adaptive control of Parkinson's state based on a nonlinear computational model with unknown parameters.

    Su, Fei; Wang, Jiang; Deng, Bin; Wei, Xi-Le; Chen, Ying-Yuan; Liu, Chen; Li, Hui-Yan

    2015-02-01

    The objective here is to explore the use of adaptive input-output feedback linearization method to achieve an improved deep brain stimulation (DBS) algorithm for closed-loop control of Parkinson's state. The control law is based on a highly nonlinear computational model of Parkinson's disease (PD) with unknown parameters. The restoration of thalamic relay reliability is formulated as the desired outcome of the adaptive control methodology, and the DBS waveform is the control input. The control input is adjusted in real time according to estimates of unknown parameters as well as the feedback signal. Simulation results show that the proposed adaptive control algorithm succeeds in restoring the relay reliability of the thalamus, and at the same time achieves accurate estimation of unknown parameters. Our findings point to the potential value of adaptive control approach that could be used to regulate DBS waveform in more effective treatment of PD.

  11. Building a RAPPOR with the Unknown: Privacy-Preserving Learning of Associations and Data Dictionaries

    Fanti Giulia

    2016-07-01

    Full Text Available Techniques based on randomized response enable the collection of potentially sensitive data from clients in a privacy-preserving manner with strong local differential privacy guarantees. A recent such technology, RAPPOR [12], enables estimation of the marginal frequencies of a set of strings via privacy-preserving crowdsourcing. However, this original estimation process relies on a known dictionary of possible strings; in practice, this dictionary can be extremely large and/or unknown. In this paper, we propose a novel decoding algorithm for the RAPPOR mechanism that enables the estimation of “unknown unknowns,” i.e., strings we do not know we should be estimating. To enable learning without explicit dictionary knowledge, we develop methodology for estimating the joint distribution of multiple variables collected with RAPPOR. Our contributions are not RAPPOR-specific, and can be generalized to other local differential privacy mechanisms for learning distributions of string-valued random variables.

  12. Ratbot automatic navigation by electrical reward stimulation based on distance measurement in unknown environments.

    Gao, Liqiang; Sun, Chao; Zhang, Chen; Zheng, Nenggan; Chen, Weidong; Zheng, Xiaoxiang

    2013-01-01

    Traditional automatic navigation methods for bio-robots are constrained to configured environments and thus can't be applied to tasks in unknown environments. With no consideration of bio-robot's own innate living ability and treating bio-robots in the same way as mechanical robots, those methods neglect the intelligence behavior of animals. This paper proposes a novel ratbot automatic navigation method in unknown environments using only reward stimulation and distance measurement. By utilizing rat's habit of thigmotaxis and its reward-seeking behavior, this method is able to incorporate rat's intrinsic intelligence of obstacle avoidance and path searching into navigation. Experiment results show that this method works robustly and can successfully navigate the ratbot to a target in the unknown environment. This work might put a solid base for application of ratbots and also has significant implication of automatic navigation for other bio-robots as well.

  13. Neuroendocrine Merkel cell nodal carcinoma of unknown primary site: management and outcomes of a rare entity.

    Kotteas, E A; Pavlidis, N

    2015-04-01

    Merkel cell nodal carcinoma of unknown primary (MCCUP) is a rare neuroendocrine tumour with distinct clinical and biological behaviour. We conducted a review of retrospective data extracted from 90 patients focusing on the management and outcome of this disease. We also compared life expectancy of these patients with the outcome of patients with known Merkel primaries and with neuroendocrine cancers of unidentifiable primary. There is a limited body of data for this type of malignancy, however, patients with Merkel cell nodal carcinoma of unknown primary site, seem to have better survival when treated aggressively than patients with cutaneous Merkel tumours of the same stage and equal survival with patients with low-grade neuroendocrine tumour of unknown origin. The lack of prospective trials, and the inadequate data, hamper the management of these tumours. Establishment of treatment guidelines is urgently needed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. STRUCTURAL ORGANIZATION OF BACTERIAL UREASES

    Lisnyak YuV

    2016-09-01

    Full Text Available This brief review concerns the basic principles of structural organization of multi-subunit bacterial ureases and formation of their quaternary structure. Urease is a nickel-containing enzyme (urea amidohydrolase, ЕС 3.5.1.5 that catalyses the hydrolysis of urea to get ammonia and carbamate which then decomposes with water to get ammonia and carbon dioxide. Urease is produced by bacteria, fungi, yeast and plants. On the basis of similarities in amino acid sequences, ureases assumed to have a similar structure and conservative catalytic mechanism. Within past two decades bacterial ureases have gained much attention in research field as a virulence factor in human and animal infections. The first crystal structure of urease has been determined for that from Klebsiella aerogenes. The native enzyme consists of three subunits, UreA (α-chain, UreB (β-chain and UreC (γ-chain, and contains four structural domains: two in α-chain (α-domain 1 and α-domain-2, one in β- and one in γ-chain. These three chains form a T-shaped heterotrimer αβγ. Three αβγ heterotrimers form quaternary complex (αβγ3. In case of Helicobacter pilori, the analogous trimers of corresponding dimeric subunits (αβ3 form tetrameric structure ((αβ34 in which four trimers are situated at the vertexes of the regular triangle pyramid. Active center is located in α-domain 1 and contains two atoms of nickel coordinated by residues His134, His136, carboxylated Lys217, His 246, His272 and Asp360, as well as residues involved in binding (His219 and catalysis (His320. Active site is capped by a flap that controls substrate ingress to and product egress from the dinickel center. Urease requires accessory proteins (UreD, UreF, UreG and UreE for the correct assembly of their Ni-containing metallocenters. The accessory proteins UreD, UreF, and UreG sequentially bind to the apoprotein (UreABC3 to finally form (UreABC-UreDFG3 activation complex. UreE metallochaperone delivers

  15. Expression of Toll-like receptor 9 and response to bacterial CpG oligodeoxynucleotides in human intestinal epithelium

    Pedersen, G; Andresen, Lars; Matthiessen, M W

    2005-01-01

    Recognition of repeat CpG motifs, which are common in bacterial, but not in mammalian, DNA, through Toll-like receptor (TLR)9 is an integral part of the innate immune system. As the role of TLR9 in the human gut is unknown, we determined the spectrum of TLR9 expression in normal and inflamed colo...... in vitro despite spontaneous TLR9 gene expression. This suggests that the human epithelium is able to avoid inappropriate immune responses to luminal bacterial products through modulation of the TLR9 pathway....

  16. Accessory papillary muscles and papillary muscle hypertrophy are associated with sudden cardiac arrest of unknown cause.

    Uhm, Jae-Sun; Youn, Jong-Chan; Lee, Hye-Jeong; Park, Junbeom; Park, Jin-Kyu; Shim, Chi Young; Hong, Geu-Ru; Joung, Boyoung; Pak, Hui-Nam; Lee, Moon-Hyoung

    2015-10-15

    The present study was performed for elucidating the associations between the morphology of the papillary muscles (PMs) and sudden cardiac arrest (SCA). We retrospectively reviewed history, laboratory data, electrocardiography, echocardiography, coronary angiography, and cardiac CT/MRI for 190 patients with SCA. The prevalence of accessory PMs and PM hypertrophy in patients with SCA of unknown cause was compared with that in patients with SCA of known causes and 98 age- and sex-matched patients without SCA. An accessory PM was defined as a PM with origins separated from the anterolateral and posteromedial PMs, or a PM that branched into two or three bellies at the base of the anterolateral or posteromedial PM. PM hypertrophy was defined as at least one of the two PMs having a diameter of ≥1.1cm. In 49 patients (age 49.9±15.9years; 38 men) the cause of SCA was unknown, whereas 141 (age 54.2±16.6years; 121 men) had a known cause. The prevalence of accessory PMs was significantly higher in the unknown-cause group than in the known-cause group (24.5% and 7.8%, respectively; p=0.002) or the no-SCA group (7.1%, p=0.003). The same was true for PM hypertrophy (unknown-cause 12.2%, known-cause 2.1%, p=0.010; no SCA group 1.0%, p=0.006). By logistic regression, accessory PM and PM hypertrophy were independently associated with sudden cardiac arrest of unknown cause. An accessory PM and PM hypertrophy are associated with SCA of unknown cause. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Phytoplankton-Associated Bacterial Community Composition and Succession during Toxic Diatom Bloom and Non-Bloom Events.

    Sison-Mangus, Marilou P; Jiang, Sunny; Kudela, Raphael M; Mehic, Sanjin

    2016-01-01

    Pseudo-nitzschia blooms often occur in coastal and open ocean environments, sometimes leading to the production of the neurotoxin domoic acid that can cause severe negative impacts to higher trophic levels. Increasing evidence suggests a close relationship between phytoplankton bloom and bacterial assemblages, however, the microbial composition and succession during a bloom process is unknown. Here, we investigate the bacterial assemblages before, during and after toxic and non-toxic Pseudo-nitzschia blooms to determine the patterns of bacterial succession in a natural bloom setting. Opportunistic sampling of bacterial community profiles were determined weekly at Santa Cruz Municipal Wharf by 454 pyrosequencing and analyzed together with domoic acid levels, phytoplankton community and biomass, nutrients and temperature. We asked if the bacterial communities are similar between bloom and non-bloom events and if domoic acid or the presence of toxic algal species acts as a driving force that can significantly structure phytoplankton-associated bacterial communities. We found that bacterial diversity generally increases when Pseudo-nitzschia numbers decline. Furthermore, bacterial diversity is higher when the low-DA producing P. fraudulenta dominates the algal bloom while bacterial diversity is lower when high-DA producing P. australis dominates the algal bloom, suggesting that the presence of algal toxin can structure bacterial community. We also found bloom-related succession patterns among associated bacterial groups; Gamma-proteobacteria, were dominant during low toxic P. fraudulenta blooms comprising mostly of Vibrio spp., which increased in relative abundance (6-65%) as the bloom progresses. On the other hand, Firmicutes bacteria comprising mostly of Planococcus spp. (12-86%) dominate during high toxic P. australis blooms, with the bacterial assemblage showing the same bloom-related successional patterns in three independent bloom events. Other environmental

  18. Phytoplankton-associated bacterial community composition and succession during toxic diatom bloom and non-bloom events

    Marilou P. Sison-Mangus

    2016-09-01

    Full Text Available Pseudo-nitzschia blooms often occur in coastal and open ocean environments, sometimes leading to the production of the neurotoxin domoic acid that can cause severe negative impacts to higher trophic levels. Increasing evidence suggests a close relationship between phytoplankton bloom and bacterial assemblages, however, the microbial composition and succession during a bloom process is unknown. Here, we investigate the bacterial assemblages before, during and after toxic and non-toxic Pseudo-nitzschia blooms to determine the patterns of bacterial succession in a natural bloom setting. Opportunistic sampling of bacterial community profiles were determined weekly at Santa Cruz Municipal Wharf by 454 pyrosequencing and analyzed together with domoic acid levels, phytoplankton community and biomass, nutrients and temperature. We asked if the bacterial communities are similar between bloom and non-bloom events and if domoic acid or the presence of toxic algal species acts as a driving force that can significantly structure phytoplankton-associated bacterial communities. We found that bacterial diversity generally increases when Pseudo-nitzschia numbers decline. Furthermore, bacterial diversity is higher when the low-DA producing P. fraudulenta dominates the algal bloom while bacterial diversity is lower when high-DA producing P. australis dominates the algal bloom, suggesting that the presence of algal toxin can structure bacterial community. We also found bloom-related succession patterns among associated bacterial groups; Gamma-proteobacteria, were dominant during low toxic P. fraudulenta blooms comprising mostly of Vibrio spp., which increased in relative abundance (6%-65% as the bloom progresses. On the other hand, Firmicutes bacteria comprising mostly of Planococcus spp. (12%- 86% dominate during high toxic P. australis blooms, with the bacterial assemblage showing the same bloom-related successional patterns in 3 independent bloom events. Other

  19. Bacterial mycophagy: definition and diagnosis of a unique bacterial-fungal interaction

    Leveau, J.H.J.; Preston, G.M.

    2008-01-01

    This review analyses the phenomenon of bacterial mycophagy, which we define as a set of phenotypic behaviours that enable bacteria to obtain nutrients from living fungi and thus allow the conversion of fungal into bacterial biomass. We recognize three types of bacterial strategies to derive

  20. Modifications to nuclear power plants. Safety guide

    2004-01-01

    This Safety Guide was prepared under the IAEA's programme for safety standards for nuclear power plants. It supplements Section 7 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation, which establishes the safety requirements for the modification of nuclear power plants. Reasons for carrying out modifications to nuclear power plants may include: (1) maintaining or strengthening existing safety provisions and thus maintaining consistency with or improving on the current design. (2) recovering from plant faults. (3) improving the thermal performance or increasing the power rating of the plant. (4) increasing the maintainability of the plant, reducing the radiation exposure of personnel or reducing the costs of plant maintenance. And (5) extending the design life of the plant. Most modifications, made on the basis of operating experience, are intended to improve on the design or to improve operational performance and flexibility. Some are rendered necessary by new regulatory requirements, ageing of the plant or obsolescence of equipment. However, the benefits of regularly updating the plant design can be jeopardized if modifications are not kept under rigorous control throughout the lifetime of the plant. The need to reduce costs and improve efficiency, in combination with changes to the structure of the electricity generation sector of the economy in many countries, has led many companies to make changes in the structure of the operating organization for nuclear power plants. Whatever the reason for such organizational changes, consideration should be given to the effects of those changes with the aim of ensuring that they would have no impacts that would compromise the safety of the plant. The objective of this Safety Guide is to provide guidance and recommendations on controlling activities relating to modifications at nuclear power plants in order to reduce risk and to ensure that the configuration of the plant is at all times under