51 research outputs found

    Life on Arginine for Mycoplasma hominis: Clues from Its Minimal Genome and Comparison with Other Human Urogenital Mycoplasmas

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    Mycoplasma hominis is an opportunistic human mycoplasma. Two other pathogenic human species, M. genitalium and Ureaplasma parvum, reside within the same natural niche as M. hominis: the urogenital tract. These three species have overlapping, but distinct, pathogenic roles. They have minimal genomes and, thus, reduced metabolic capabilities characterized by distinct energy-generating pathways. Analysis of the M. hominis PG21 genome sequence revealed that it is the second smallest genome among self-replicating free living organisms (665,445 bp, 537 coding sequences (CDSs)). Five clusters of genes were predicted to have undergone horizontal gene transfer (HGT) between M. hominis and the phylogenetically distant U. parvum species. We reconstructed M. hominis metabolic pathways from the predicted genes, with particular emphasis on energy-generating pathways. The Embden–Meyerhoff–Parnas pathway was incomplete, with a single enzyme absent. We identified the three proteins constituting the arginine dihydrolase pathway. This pathway was found essential to promote growth in vivo. The predicted presence of dimethylarginine dimethylaminohydrolase suggested that arginine catabolism is more complex than initially described. This enzyme may have been acquired by HGT from non-mollicute bacteria. Comparison of the three minimal mollicute genomes showed that 247 CDSs were common to all three genomes, whereas 220 CDSs were specific to M. hominis, 172 CDSs were specific to M. genitalium, and 280 CDSs were specific to U. parvum. Within these species-specific genes, two major sets of genes could be identified: one including genes involved in various energy-generating pathways, depending on the energy source used (glucose, urea, or arginine) and another involved in cytadherence and virulence. Therefore, a minimal mycoplasma cell, not including cytadherence and virulence-related genes, could be envisaged containing a core genome (247 genes), plus a set of genes required for providing energy. For M. hominis, this set would include 247+9 genes, resulting in a theoretical minimal genome of 256 genes

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    The built noble lodging houses built in the Northeast of Maine

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    Les campagnes du Maine conservent encore aujourd’hui de nombreux logis nobles maçonnés, qui se démarquent assez facilement de l’habitat paysan et dont les constructions ont été réalisées essentiellement entre le XIVe et le XVIe siècle. Partant de ce constat, une étude se basant sur un inventaire le plus exhaustif possible de ces demeures semble être l’un des meilleurs moyens pour mieux connaître le mode de vie des seigneurs de cette période par l’intermédiaire de leur habitat. Ainsi a été constitué un corpus rassemblant deux-cent-quinze sites encore visibles aujourd’hui dans l’actuel arrondissement de Mamers (cantons de Beaumont-sur-Sarthe, Bonnétable, Bouloire, Conlie, La Ferté-Bernard, Fresnay-sur-Sarthe, La Fresnaye-sur-Chedouet, Mamers, Marolles-le-Braults, Montfort-le-Gesnois, Montmirail, Saint-Calais, Saint-Paterne, Sillé-le-Guillaume, Tuffé et Vibraye). L’étude architecturale montre les caractéristiques et particularismes de ces sites. Il s’avère qu’ils sont en général bâtis sur un plan rectangulaire et leur mode de construction semble être assez similaire d’un édifice à l’autre. Ainsi, il existe des caractéristiques qui font que ces maisons sont facilement reconnaissables. L’organisation intérieure témoigne de l’évolution des logis entre le XIVe et le XVIe siècle. Quelques sites présentent des aménagements fonctionnels reflétant une recherche de confort. Certains d’entre eux s’avèrent aussi être symboliques comme les escaliers et les cheminées qui arborent les prétentions du détenteur avec parfois la présence d’écus. La présence d’éléments décoratifs révèle les goûts des détenteurs ainsi que leurs moyens financiers. Si certains des logis étudiés présentent un répertoire décoratif totalement issu du goût gothique ou renaissance, certains d’entre eux présentent des ornements « hybrides » entre les deux styles. Ce fait, témoigne que les logis bâtis ou restaurés après la guerre de Cent Ans, sont élaborés selon un modèle architectural de transition entre Moyen Âge et Renaissance.Nowadays, Maine’s countryside still keeps a lot of noble houses which were built by stonework. These houses differentiate themselves easily from peasantry habitat and were essentially built between the 14thand the 16thcenturies. Based from that information, a study based on an inventory (the much complete as possible) of these houses seemed to be the best working way to know about the Lord’s lifestyles, through their habitats, during this period. A corpus was realized and has bring more than 215 sites together, which are still visible today, in the actual arrondissement de Mamers (cantons de Beaumont-sur-Sarthe, Bonnétable, Bouloire, Conlie, La Ferté-Bernard, Fresnay-sur-Sarthe, La Fresnaye-sur-Chedouet, Mamers, Marolles-le-Braults, Montfort-le-Gesnois, Montmirail, Saint-Calais, Saint-Paterne, Sillé-le-Guillaume, Tuffé and Vibraye). Architectural study shows characteristics and particularities of these sites. They are generally built in accordance with a rectangular plan and these methods of construction seemed to be similar from an edifice to another: the characteristics of these houses easily helped to recognize them. The internal organization gives evidence of the house’s evolution between the 14thand 16thcenturies. Some sites contain functional facilities which show a comfort research. Some of them are more symbolic as the staircases and fireplaces which show the holder’s ambitions with sometimes the presence of shields. Decorative elements show the owner’s taste and their financial resources. If some of the home’s studies present a decorative repertory from Gothic taste or Renaissance taste, some of them present hybrid ornaments between the two styles. This fact testify that houses built or restored after the Hundred Years War were elaborate in accordance with an architectural model of transition between Middle Age and Renaissance

    Les logis nobles maçonnés bâtis dans le nord-est du Maine (XIVe- XVIe siècle)

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    Nowadays, Maine’s countryside still keeps a lot of noble houses which were built by stonework. These houses differentiate themselves easily from peasantry habitat and were essentially built between the 14thand the 16thcenturies. Based from that information, a study based on an inventory (the much complete as possible) of these houses seemed to be the best working way to know about the Lord’s lifestyles, through their habitats, during this period. A corpus was realized and has bring more than 215 sites together, which are still visible today, in the actual arrondissement de Mamers (cantons de Beaumont-sur-Sarthe, Bonnétable, Bouloire, Conlie, La Ferté-Bernard, Fresnay-sur-Sarthe, La Fresnaye-sur-Chedouet, Mamers, Marolles-le-Braults, Montfort-le-Gesnois, Montmirail, Saint-Calais, Saint-Paterne, Sillé-le-Guillaume, Tuffé and Vibraye). Architectural study shows characteristics and particularities of these sites. They are generally built in accordance with a rectangular plan and these methods of construction seemed to be similar from an edifice to another: the characteristics of these houses easily helped to recognize them. The internal organization gives evidence of the house’s evolution between the 14thand 16thcenturies. Some sites contain functional facilities which show a comfort research. Some of them are more symbolic as the staircases and fireplaces which show the holder’s ambitions with sometimes the presence of shields. Decorative elements show the owner’s taste and their financial resources. If some of the home’s studies present a decorative repertory from Gothic taste or Renaissance taste, some of them present hybrid ornaments between the two styles. This fact testify that houses built or restored after the Hundred Years War were elaborate in accordance with an architectural model of transition between Middle Age and Renaissance.Les campagnes du Maine conservent encore aujourd’hui de nombreux logis nobles maçonnés, qui se démarquent assez facilement de l’habitat paysan et dont les constructions ont été réalisées essentiellement entre le XIVe et le XVIe siècle. Partant de ce constat, une étude se basant sur un inventaire le plus exhaustif possible de ces demeures semble être l’un des meilleurs moyens pour mieux connaître le mode de vie des seigneurs de cette période par l’intermédiaire de leur habitat. Ainsi a été constitué un corpus rassemblant deux-cent-quinze sites encore visibles aujourd’hui dans l’actuel arrondissement de Mamers (cantons de Beaumont-sur-Sarthe, Bonnétable, Bouloire, Conlie, La Ferté-Bernard, Fresnay-sur-Sarthe, La Fresnaye-sur-Chedouet, Mamers, Marolles-le-Braults, Montfort-le-Gesnois, Montmirail, Saint-Calais, Saint-Paterne, Sillé-le-Guillaume, Tuffé et Vibraye). L’étude architecturale montre les caractéristiques et particularismes de ces sites. Il s’avère qu’ils sont en général bâtis sur un plan rectangulaire et leur mode de construction semble être assez similaire d’un édifice à l’autre. Ainsi, il existe des caractéristiques qui font que ces maisons sont facilement reconnaissables. L’organisation intérieure témoigne de l’évolution des logis entre le XIVe et le XVIe siècle. Quelques sites présentent des aménagements fonctionnels reflétant une recherche de confort. Certains d’entre eux s’avèrent aussi être symboliques comme les escaliers et les cheminées qui arborent les prétentions du détenteur avec parfois la présence d’écus. La présence d’éléments décoratifs révèle les goûts des détenteurs ainsi que leurs moyens financiers. Si certains des logis étudiés présentent un répertoire décoratif totalement issu du goût gothique ou renaissance, certains d’entre eux présentent des ornements « hybrides » entre les deux styles. Ce fait, témoigne que les logis bâtis ou restaurés après la guerre de Cent Ans, sont élaborés selon un modèle architectural de transition entre Moyen Âge et Renaissance

    Tools for industrial security assessment

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    Face aux menaces grandissantes liées à la malveillance et au terrorisme, les sites industriels sont amenés à évaluer leur niveau de sûreté par une méthode appropriée. Cette évaluation conduit à classer les sites ou installations selon leur criticité et à définir les mesures techniques et organisationnelles adaptées au risque.As the threats of malevolence and terrorism are increasing, industrial sites have to assess their security level with an appropriate method. At the end of this assessment, sites or installations are ranked according to their criticality, technical and organizational measures are defined in order to mitigate the risk

    Identification, expression and serological evaluation of the recombinant ATP synthase beta subunit of <it>Mycoplasma pneumoniae</it>

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    <p>Abstract</p> <p>Background</p> <p><it>Mycoplasma pneumoniae </it>is responsible for acute respiratory tract infections (RTIs) common in children and young adults. As <it>M. pneumoniae </it>is innately resistant to β-lactams antibiotics usually given as the first-line treatment for RTIs, specific and early diagnosis is important in order to select the right treatment. Serology is the most used diagnostic method for <it>M. pneumoniae </it>infections.</p> <p>Results</p> <p>In this study, we identified the <it>M. pneumoniae </it>ATP synthase beta subunit (AtpD) by serologic proteome analysis and evaluated its usefulness in the development of a serological assay. We successfully expressed and purified recombinant AtpD (rAtpD) protein, which was recognised by serum samples from <it>M. pneumoniae</it>-infected patient in immunoblots. The performance of the recombinant protein rAtpD was studied using a panel of serum samples from 103 infected patients and 86 healthy blood donors in an in-house IgM, IgA and IgG enzyme-linked immunosorbent assay (ELISA). The results of this assay were then compared with those of an in-house ELISA with a recombinant C-terminal fragment of the P1 adhesin (rP1-C) and of the commercial Ani Labsystems ELISA kit using an adhesin P1-enriched whole-cell extract. Performances of the rAtpD and rP1-C antigen combination were further assessed by binary logistic regression analysis. We showed that combination of rAtpD and rP1-C discriminated maximally between the patients infected with <it>M. pneumoniae </it>(children and adults) and the healthy subjects for the IgM class, performing better than the single recombinant antigens or the commercial whole-cell extract.</p> <p>Conclusion</p> <p>These results suggest that AtpD can be used as an antigen for the immunodiagnosis of early and acute <it>M. pneumoniae </it>infection in association with adhesin P1, providing an excellent starting point for the development of point-of-care diagnostic assays.</p

    Alterations in Topoisomerase IV and DNA Gyrase in Quinolone-Resistant Mutants of Mycoplasma hominis Obtained In Vitro

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    Mycoplasma hominis mutants were selected stepwise for resistance to ofloxacin and sparfloxacin, and their gyrA, gyrB, parC, and parE quinolone resistance-determining regions were characterized. For ofloxacin, four rounds of selection yielded six first-, six second-, five third-, and two fourth-step mutants. The first-step mutants harbored a single Asp426→Asn substitution in ParE. GyrA changes (Ser83→Leu or Trp) were found only from the third round of selection. With sparfloxacin, three rounds of selection generated 4 first-, 7 second-, and 10 third-step mutants. In contrast to ofloxacin resistance, GyrA mutations (Ser83→Leu or Ser84→Trp) were detected in the first-step mutants prior to ParC changes (Glu84→Lys), which appeared only after the second round of selection. Further analysis of eight multistep-selected mutants of M. hominis that were previously described (2) revealed that they carried mutations in ParE (Asp426→Asn), GyrA (Ser83→Leu) and ParE (Asp426→Asn), GyrA (Ser83→Leu) and ParC (Ser80→Ile), or ParC (Ser80→Ile) alone, depending on the fluoroquinolone used for selection, i.e., ciprofloxacin, norfloxacin, ofloxacin, or pefloxacin, respectively. These data indicate that in M. hominis DNA gyrase is the primary target of sparfloxacin whereas topoisomerase IV is the primary target of pefloxacin, ofloxacin, and ciprofloxacin

    The Image of Capua and Its Inhabitants in the Titus Livius' Work

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    Целью данного исследования является выявление основных черт, которые, с точки зрения Тита Ливия, характеризовали Капую и её жителей. Даётся оценка степени объективности этого образа. The aim of this research is to identify key features which, from the standpoint of Titus Livius, were typical for Capua and its inhabitants. The degree of objectivity of this image is evaluated
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