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Sample records for mycoplasma mobile gliding

  1. Gliding Direction of Mycoplasma mobile

    PubMed Central

    Morio, Hanako; Kasai, Taishi

    2015-01-01

    ABSTRACT Mycoplasma mobile glides in the direction of its cell pole by a unique mechanism in which hundreds of legs, each protruding from its own gliding unit, catch, pull, and release sialylated oligosaccharides fixed on a solid surface. In this study, we found that 77% of cells glided to the left with a change in direction of 8.4° ± 17.6° μm−1 displacement. The cell body did not roll around the cell axis, and elongated, thinner cells also glided while tracing a curved trajectory to the left. Under viscous conditions, the range of deviation of the gliding direction decreased. In the presence of 250 μM free sialyllactose, in which the binding of the legs (i.e., the catching of sialylated oligosaccharides) was reduced, 70% and 30% of cells glided to the left and the right, respectively, with changes in direction of ∼30° μm−1. The gliding ghosts, in which a cell was permeabilized by Triton X-100 and reactivated by ATP, glided more straightly. These results can be explained by the following assumptions based on the suggested gliding machinery and mechanism: (i) the units of gliding machinery may be aligned helically around the cell, (ii) the legs extend via the process of thermal fluctuation and catch the sialylated oligosaccharides, and (iii) the legs generate a propulsion force that is tilted from the cell axis to the left in 70% and to the right in 30% of cells. IMPORTANCE Mycoplasmas are bacteria that are generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide. Although these species appear to consistently glide in the direction of the protrusion, their exact gliding direction has not been examined. This study analyzed the gliding direction in detail under various conditions and, based on the results, suggested features of the machinery and the mechanism of gliding. PMID:26503848

  2. Gliding Motility of Mycoplasma mobile on Uniform Oligosaccharides

    PubMed Central

    Kasai, Taishi; Hamaguchi, Tasuku

    2015-01-01

    ABSTRACT The binding and gliding of Mycoplasma mobile on a plastic plate covered by 53 uniform oligosaccharides were analyzed. Mycoplasmas bound to and glided on only 21 of the fixed sialylated oligosaccharides (SOs), showing that sialic acid is essential as the binding target. The affinities were mostly consistent with our previous results on the inhibitory effects of free SOs and suggested that M. mobile recognizes SOs from the nonreducing end with four continuous sites as follows. (i and ii) A sialic acid at the nonreducing end is tightly recognized by tandemly connected two sites. (iii) The third site is recognized by a loose groove that may be affected by branches. (iv) The fourth site is recognized by a large groove that may be enhanced by branches, especially those with a negative charge. The cells glided on uniform SOs in manners apparently similar to those of the gliding on mixed SOs. The gliding speed was related inversely to the mycoplasma's affinity for SO, suggesting that the detaching step may be one of the speed determinants. The cells glided faster and with smaller fluctuations on the uniform SOs than on the mixtures, suggesting that the drag caused by the variation in SOs influences gliding behaviors. IMPORTANCE Mycoplasma is a group of bacteria generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide in the direction of the protrusion. These procedures are essential for parasitism. Usually, mycoplasmas glide on mixed sialylated oligosaccharides (SOs) derived from glycoprotein and glycolipid. Since gliding motility on uniform oligosaccharides has never been observed, this study gives critical information about recognition and interaction between receptors and SOs. PMID:26148712

  3. Unitary step of gliding machinery in Mycoplasma mobile.

    PubMed

    Kinosita, Yoshiaki; Nakane, Daisuke; Sugawa, Mitsuhiro; Masaike, Tomoko; Mizutani, Kana; Miyata, Makoto; Nishizaka, Takayuki

    2014-06-10

    Among the bacteria that glide on substrate surfaces, Mycoplasma mobile is one of the fastest, exhibiting smooth movement with a speed of 2.0-4.5 μm⋅s(-1) with a cycle of attachment to and detachment from sialylated oligosaccharides. To study the gliding mechanism at the molecular level, we applied an assay with a fluorescently labeled and membrane-permeabilized ghost model, and investigated the motility by high precision colocalization microscopy. Under conditions designed to reduce the number of motor interactions on a randomly oriented substrate, ghosts took unitary 70-nm steps in the direction of gliding. Although it remains possible that the stepping behavior is produced by multiple interactions, our data suggest that these steps are produced by a unitary gliding machine that need not move between sites arranged on a cytoskeletal lattice.

  4. Unitary step of gliding machinery in Mycoplasma mobile

    PubMed Central

    Kinosita, Yoshiaki; Nakane, Daisuke; Sugawa, Mitsuhiro; Masaike, Tomoko; Mizutani, Kana; Miyata, Makoto; Nishizaka, Takayuki

    2014-01-01

    Among the bacteria that glide on substrate surfaces, Mycoplasma mobile is one of the fastest, exhibiting smooth movement with a speed of 2.0–4.5 μm⋅s−1 with a cycle of attachment to and detachment from sialylated oligosaccharides. To study the gliding mechanism at the molecular level, we applied an assay with a fluorescently labeled and membrane-permeabilized ghost model, and investigated the motility by high precision colocalization microscopy. Under conditions designed to reduce the number of motor interactions on a randomly oriented substrate, ghosts took unitary 70-nm steps in the direction of gliding. Although it remains possible that the stepping behavior is produced by multiple interactions, our data suggest that these steps are produced by a unitary gliding machine that need not move between sites arranged on a cytoskeletal lattice. PMID:24912194

  5. Role of binding in Mycoplasma mobile and Mycoplasma pneumoniae gliding analyzed through inhibition by synthesized sialylated compounds.

    PubMed

    Kasai, Taishi; Nakane, Daisuke; Ishida, Hideharu; Ando, Hiromune; Kiso, Makoto; Miyata, Makoto

    2013-02-01

    Mycoplasmas, which have been shown to be the causative pathogens in recent human pneumonia epidemics, bind to solid surfaces and glide in the direction of the membrane protrusion at a pole. During gliding, the legs of the mycoplasma catch, pull, and release sialylated oligosaccharides fixed on a solid surface. Sialylated oligosaccharides are major structures on animal cell surfaces and are sometimes targeted by pathogens, such as influenza virus. In the present study, we analyzed the inhibitory effects of 16 chemically synthesized sialylated compounds on the gliding and binding of Mycoplasma mobile and Mycoplasma pneumoniae and concluded the following. (i) The recognition of sialylated oligosaccharide by mycoplasma legs proceeds in a "lock-and-key" fashion, with the binding affinity dependent on structural differences among the sialylated compounds examined. (ii) The binding of the leg and the sialylated oligosaccharide is cooperative, with Hill constants ranging from 2 to 3. (iii) Mycoplasma legs may generate a drag force after a stroke, because the gliding speed decreased and pivoting motion occurred more frequently when the number of working legs was reduced by the addition of free sialylated compounds.

  6. Mycoplasma mobile Cells Elongated by Detergent and Their Pivoting Movements in Gliding

    PubMed Central

    Nakane, Daisuke

    2012-01-01

    Mycoplasma mobile glides on solid surfaces by the repeated binding of leg structures to sialylated oligosaccharide fixed on a solid surface. To obtain information about the propulsion caused by the leg, we made elongated and stiff cells using a detergent. Within 30 min after the cells were treated with 0.1% Tween 60, the cells were elongated from 0.8 μm to 2.2 μm in length while maintaining their gliding activity. Fluorescence and electron microscopy showed that a part of the cytoskeletal structure was elongated, while the localization of proteins involved in the gliding was not modified significantly. The elongated cells glided with repeated pivoting around the cellular position of gliding machinery by 10 degrees of amplitude at a frequency of 2 to 3 times per second, suggesting that the propulsion in a line perpendicular to the cell axis can occur with different timings. The pivoting speed decreased as the cell length increased, probably from the load generated by the friction. The torque required to achieve the actual pivoting increased with the cell length without saturation, reaching 54.7 pN nm at 4.3 μm in cell length. PMID:22001513

  7. Directed Binding of Gliding Bacterium, Mycoplasma mobile, Shown by Detachment Force and Bond Lifetime

    PubMed Central

    Tanaka, Akihiro; Nakane, Daisuke; Mizutani, Masaki; Nishizaka, Takayuki

    2016-01-01

    ABSTRACT Mycoplasma mobile, a fish-pathogenic bacterium, features a protrusion that enables it to glide smoothly on solid surfaces at a velocity of up to 4.5 µm s−1 in the direction of the protrusion. M. mobile glides by a repeated catch-pull-release of sialylated oligosaccharides fixed on a solid surface by hundreds of 50-nm flexible “legs” sticking out from the protrusion. This gliding mechanism may be explained by a possible directed binding of each leg with sialylated oligosaccharides, by which the leg can be detached more easily forward than backward. In the present study, we used a polystyrene bead held by optical tweezers to detach a starved cell at rest from a glass surface coated with sialylated oligosaccharides and concluded that the detachment force forward is 1.6- to 1.8-fold less than that backward, which may be linked to a catch bond-like behavior of the cell. These results suggest that this directed binding has a critical role in the gliding mechanism. PMID:27353751

  8. Analysis of energy sources for Mycoplasma penetrans gliding motility.

    PubMed

    Jurkovic, Dominika A; Hughes, Michael R; Balish, Mitchell F

    2013-01-01

    Mycoplasma penetrans, a potential human pathogen found mainly in HIV-infected individuals, uses a tip structure for both adherence and gliding motility. To improve our understanding of the molecular mechanism of M. penetrans gliding motility, we used chemical inhibitors of energy sources associated with motility of other organisms to determine which of these is used by M. penetrans and also tested whether gliding speed responded to temperature and pH. Mycoplasma penetrans gliding motility was not eliminated in the presence of a proton motive force inhibitor, a sodium motive force inhibitor, or an agent that depletes cellular ATP. At near-neutral pH, gliding speed increased as temperature increased. The absence of a clear chemical energy source for gliding motility and a positive correlation between speed and temperature suggest that energy derived from heat provides the major source of power for the gliding motor of M. penetrans.

  9. Mycoplasma genitalium mg200 and mg386 genes are involved in gliding motility but not in cytadherence.

    PubMed

    Pich, Oscar Q; Burgos, Raul; Ferrer-Navarro, Mario; Querol, Enrique; Piñol, Jaume

    2006-06-01

    Isolation and characterization of transposon-generated Mycoplasma genitalium gliding-deficient mutants has implicated mg200 and mg386 genes in gliding motility. The proposed role of these genes was confirmed by restoration of the gliding phenotype in deficient mutants through gene complementation with their respective mg386 or mg200 wild-type copies. mg200 and mg386 are the first reported gliding-associated mycoplasma genes not directly involved in cytadherence. Orthologues of MG200 and MG386 proteins are also found in the slow gliding mycoplasmas, Mycoplasma pneumoniae and Mycoplasma gallisepticum, suggesting the existence of a unique set of proteins involved in slow gliding motility. MG200 and MG386 proteins share common features, such as the presence of enriched in aromatic and glycine residues boxes and an acidic and proline-rich domain, suggesting that these motifs could play a significant role in gliding motility.

  10. A Major Determinant for Gliding Motility in Mycoplasma genitalium

    PubMed Central

    Martinelli, Luca; Lalli, Daniela; García-Morales, Luis; Ratera, Mercè; Querol, Enrique; Piñol, Jaume; Fita, Ignacio; Calisto, Bárbara M.

    2015-01-01

    Several mycoplasmas, such as the emergent human pathogen Mycoplasma genitalium, developed a complex polar structure, known as the terminal organelle (TO), responsible for a new type of cellular motility, which is involved in a variety of cell functions: cell division, adherence to host cells, and virulence. The TO cytoskeleton is organized as a multisubunit dynamic motor, including three main ultrastructures: the terminal button, the electrodense core, and the wheel complex. Here, we describe the interaction between MG200 and MG491, two of the main components of the TO wheel complex that connects the TO with the cell body and the cell membrane. The interaction between MG200 and MG491 has a KD in the 80 nm range, as determined by surface plasmon resonance. The interface between the two partners was confined to the “enriched in aromatic and glycine residues” (EAGR) box of MG200, previously described as a protein-protein interaction domain, and to a 25-residue-long peptide from the C-terminal region of MG491 by surface plasmon resonance and NMR spectroscopy studies. An atomic description of the MG200 EAGR box binding surface was also provided by solution NMR. An M. genitalium mutant lacking the MG491 segment corresponding to the peptide reveals specific alterations in cell motility and cell morphology indicating that the MG200-MG491 interaction plays a key role in the stability and functioning of the TO. PMID:25471372

  11. Integrated Information and Prospects for Gliding Mechanism of the Pathogenic Bacterium Mycoplasma pneumoniae

    PubMed Central

    Miyata, Makoto; Hamaguchi, Tasuku

    2016-01-01

    Mycoplasma pneumoniae forms a membrane protrusion at a cell pole and is known to adhere to solid surfaces, including animal cells, and can glide on these surfaces with a speed up to 1 μm per second. Notably, gliding appears to be involved in the infectious process in addition to providing the bacteria with a means of escaping the host's immune systems. However, the genome of M. pneumoniae does not encode any of the known genes found in other bacterial motility systems or any conventional motor proteins that are responsible for eukaryotic motility. Thus, further analysis of the mechanism underlying M. pneumoniae gliding is warranted. The gliding machinery formed as the membrane protrusion can be divided into the surface and internal structures. On the surface, P1 adhesin, a 170 kDa transmembrane protein forms an adhesin complex with other two proteins. The internal structure features a terminal button, paired plates, and a bowl (wheel) complex. In total, the organelle is composed of more than 15 proteins. By integrating the currently available information by genetics, microscopy, and structural analyses, we have suggested a working model for the architecture of the organelle. Furthermore, in this article, we suggest and discuss a possible mechanism of gliding based on the structural model, in which the force generated around the bowl complex transmits through the paired plates, reaching the adhesin complex, resulting in the repeated catch of sialylated oligosaccharides on the host surface by the adhesin complex. PMID:27446003

  12. Integrated Information and Prospects for Gliding Mechanism of the Pathogenic Bacterium Mycoplasma pneumoniae.

    PubMed

    Miyata, Makoto; Hamaguchi, Tasuku

    2016-01-01

    Mycoplasma pneumoniae forms a membrane protrusion at a cell pole and is known to adhere to solid surfaces, including animal cells, and can glide on these surfaces with a speed up to 1 μm per second. Notably, gliding appears to be involved in the infectious process in addition to providing the bacteria with a means of escaping the host's immune systems. However, the genome of M. pneumoniae does not encode any of the known genes found in other bacterial motility systems or any conventional motor proteins that are responsible for eukaryotic motility. Thus, further analysis of the mechanism underlying M. pneumoniae gliding is warranted. The gliding machinery formed as the membrane protrusion can be divided into the surface and internal structures. On the surface, P1 adhesin, a 170 kDa transmembrane protein forms an adhesin complex with other two proteins. The internal structure features a terminal button, paired plates, and a bowl (wheel) complex. In total, the organelle is composed of more than 15 proteins. By integrating the currently available information by genetics, microscopy, and structural analyses, we have suggested a working model for the architecture of the organelle. Furthermore, in this article, we suggest and discuss a possible mechanism of gliding based on the structural model, in which the force generated around the bowl complex transmits through the paired plates, reaching the adhesin complex, resulting in the repeated catch of sialylated oligosaccharides on the host surface by the adhesin complex.

  13. Structural Study of MPN387, an Essential Protein for Gliding Motility of a Human-Pathogenic Bacterium, Mycoplasma pneumoniae

    PubMed Central

    Kawakita, Yoshito; Kinoshita, Miki; Furukawa, Yukio; Tulum, Isil; Tahara, Yuhei O.; Katayama, Eisaku

    2016-01-01

    ABSTRACT Mycoplasma pneumoniae is a human pathogen that glides on host cell surfaces with repeated catch and release of sialylated oligosaccharides. At a pole, this organism forms a protrusion called the attachment organelle, which is composed of surface structures, including P1 adhesin and the internal core structure. The core structure can be divided into three parts, the terminal button, paired plates, and bowl complex, aligned in that order from the front end of the protrusion. To elucidate the gliding mechanism, we focused on MPN387, a component protein of the bowl complex which is essential for gliding but dispensable for cytadherence. The predicted amino acid sequence showed that the protein features a coiled-coil region spanning residue 72 to residue 290 of the total of 358 amino acids in the protein. Recombinant MPN387 proteins were isolated with and without an enhanced yellow fluorescent protein (EYFP) fusion tag and analyzed by gel filtration chromatography, circular dichroism spectroscopy, analytical ultracentrifugation, partial proteolysis, and rotary-shadowing electron microscopy. The results showed that MPN387 is a dumbbell-shaped homodimer that is about 42.7 nm in length and 9.1 nm in diameter and includes a 24.5-nm-long central parallel coiled-coil part. The molecular image was superimposed onto the electron micrograph based on the localizing position mapped by fluorescent protein tagging. A proposed role of this protein in the gliding mechanism is discussed. IMPORTANCE Human mycoplasma pneumonia is caused by a pathogenic bacterium, Mycoplasma pneumoniae. This tiny, 2-μm-long bacterium is suggested to infect humans by gliding on the surface of the trachea through binding to sialylated oligosaccharides. The mechanism underlying mycoplasmagliding motility” is not related to any other well-studied motility systems, such as bacterial flagella and eukaryotic motor proteins. Here, we isolated and analyzed the structure of a key protein which is

  14. Structural Study of MPN387, an Essential Protein for Gliding Motility of a Human-Pathogenic Bacterium, Mycoplasma pneumoniae.

    PubMed

    Kawakita, Yoshito; Kinoshita, Miki; Furukawa, Yukio; Tulum, Isil; Tahara, Yuhei O; Katayama, Eisaku; Namba, Keiichi; Miyata, Makoto

    2016-09-01

    Mycoplasma pneumoniae is a human pathogen that glides on host cell surfaces with repeated catch and release of sialylated oligosaccharides. At a pole, this organism forms a protrusion called the attachment organelle, which is composed of surface structures, including P1 adhesin and the internal core structure. The core structure can be divided into three parts, the terminal button, paired plates, and bowl complex, aligned in that order from the front end of the protrusion. To elucidate the gliding mechanism, we focused on MPN387, a component protein of the bowl complex which is essential for gliding but dispensable for cytadherence. The predicted amino acid sequence showed that the protein features a coiled-coil region spanning residue 72 to residue 290 of the total of 358 amino acids in the protein. Recombinant MPN387 proteins were isolated with and without an enhanced yellow fluorescent protein (EYFP) fusion tag and analyzed by gel filtration chromatography, circular dichroism spectroscopy, analytical ultracentrifugation, partial proteolysis, and rotary-shadowing electron microscopy. The results showed that MPN387 is a dumbbell-shaped homodimer that is about 42.7 nm in length and 9.1 nm in diameter and includes a 24.5-nm-long central parallel coiled-coil part. The molecular image was superimposed onto the electron micrograph based on the localizing position mapped by fluorescent protein tagging. A proposed role of this protein in the gliding mechanism is discussed. Human mycoplasma pneumonia is caused by a pathogenic bacterium, Mycoplasma pneumoniae This tiny, 2-μm-long bacterium is suggested to infect humans by gliding on the surface of the trachea through binding to sialylated oligosaccharides. The mechanism underlying mycoplasma "gliding motility" is not related to any other well-studied motility systems, such as bacterial flagella and eukaryotic motor proteins. Here, we isolated and analyzed the structure of a key protein which is directly involved in the

  15. P65 Truncation Impacts P30 Dynamics during Mycoplasma pneumoniae Gliding

    PubMed Central

    Hasselbring, Benjamin M.; Sheppard, Edward S.

    2012-01-01

    The cell wall-less prokaryote Mycoplasma pneumoniae is a major cause of community-acquired bronchitis and pneumonia in humans. Colonization is mediated largely by a differentiated terminal organelle, which is also the leading end in gliding motility. Cytadherence-associated proteins P30 and P65 appear to traffic concurrently to the distal end of developing terminal organelles. Here, truncation of P65 due to transposon insertion in the corresponding gene resulted in lower gliding velocity, reduced cytadherence, and decreased steady-state levels of several terminal organelle proteins, including P30. Utilizing fluorescent protein fusions, we followed terminal organelle development over time. New P30 foci appeared at nascent terminal organelles in P65 mutants, as in the wild type. However, with forward cell motility, P30 in the P65 mutants appeared to drag toward the trailing cell pole, where it was released, yielding a fluorescent trail to which truncated P65 colocalized. In contrast, P30 was only rarely observed at the trailing end of gliding wild-type cells. Complementation with the recombinant wild-type P65 allele by transposon delivery restored P65 levels and stabilized P30 localization to the terminal organelle. PMID:22544269

  16. Kinematic Analyses of the Thumb during Simulated Posteroanterior Glide Mobilization

    PubMed Central

    Su, Fong-Chin

    2016-01-01

    Objective Thumb problems are common in some health professionals such as physical therapists. The purpose of this case-control study is to investigate the influence of clinical experience and different mobilization techniques on the kinematics of the thumb. Methods Twenty-three participants without exposure to manual techniques (the Novice Group) and fifteen physical therapists with at least 3 years of orthopedic experience (the Experienced Group) participated. The kinematics of the thumb while performing 3 different simulated posteroanterior (PA) glide mobilization techniques on a load cell was monitored. These 3 techniques were: 1) unsupported, 2) with digital support and 3) with thumb interphalangeal joint supported by the index finger. The amount of forces exerted were 25% to 100% of maximum effort at 25% increments. The main effects of experience and technique on thumb kinematics were assessed. Results Both experience and technique had main effects on the flexion/extension angles of the thumb joints. Experienced participants assumed a more flexed position at the carpometacarpal (CMC) joint, and the novice participants performed with angles closer to the neutral position (F = 7.593, p = 0.010). Participants’ metacarpophalangeal (MCP) joints were in a more flexed position while performing PA glide with thumb interphalangeal (IP) joint supported by the index as compared to the other two techniques (p < .001). Conclusions Negative correlations were generally obtained between the sagittal plane angles of adjacent thumb joints during mobilization/manipulation. Therapists are recommended to treat patient with more stable PA glide mobilization techniques, such as PA glide with thumb interphalangeal joint supported by the index finger, to prevent potential mobilization-related thumb disorders. PMID:27583407

  17. Kinematic Analyses of the Thumb during Simulated Posteroanterior Glide Mobilization.

    PubMed

    Hu, Meng-Tzu; Hsu, Ar-Tyan; Su, Fong-Chin

    2016-01-01

    Thumb problems are common in some health professionals such as physical therapists. The purpose of this case-control study is to investigate the influence of clinical experience and different mobilization techniques on the kinematics of the thumb. Twenty-three participants without exposure to manual techniques (the Novice Group) and fifteen physical therapists with at least 3 years of orthopedic experience (the Experienced Group) participated. The kinematics of the thumb while performing 3 different simulated posteroanterior (PA) glide mobilization techniques on a load cell was monitored. These 3 techniques were: 1) unsupported, 2) with digital support and 3) with thumb interphalangeal joint supported by the index finger. The amount of forces exerted were 25% to 100% of maximum effort at 25% increments. The main effects of experience and technique on thumb kinematics were assessed. Both experience and technique had main effects on the flexion/extension angles of the thumb joints. Experienced participants assumed a more flexed position at the carpometacarpal (CMC) joint, and the novice participants performed with angles closer to the neutral position (F = 7.593, p = 0.010). Participants' metacarpophalangeal (MCP) joints were in a more flexed position while performing PA glide with thumb interphalangeal (IP) joint supported by the index as compared to the other two techniques (p < .001). Negative correlations were generally obtained between the sagittal plane angles of adjacent thumb joints during mobilization/manipulation. Therapists are recommended to treat patient with more stable PA glide mobilization techniques, such as PA glide with thumb interphalangeal joint supported by the index finger, to prevent potential mobilization-related thumb disorders.

  18. Role of Mycoplasma genitalium MG218 and MG317 cytoskeletal proteins in terminal organelle organization, gliding motility and cytadherence.

    PubMed

    Pich, Oscar Q; Burgos, Raul; Ferrer-Navarro, Mario; Querol, Enrique; Piñol, Jaume

    2008-10-01

    The terminal organelle is a differentiated structure that plays a key role in mycoplasma cytadherence and locomotion. For this reason, the analysis of Mycoplasma genitalium mutants displaying anomalous terminal organelles could improve our knowledge regarding the structural elements required for proper locomotion. In this study, we isolated several M. genitalium mutants having transposon insertions within the mg218 or mg317 genes, which encode the orthologues of Mycoplasma pneumoniae HMW2 and HMW3 cytoskeletal proteins, respectively. As expected, mg218(-) and mg317(-) mutants exhibit a reduced gliding motility, although their ability to attach to solid surfaces was not completely abolished. Interestingly, most of the mg218(-) mutants expressed N-terminal MG218 derivatives and showed the presence of short terminal organelles retaining many of the functions displayed by this structure in the wild-type strain, suggesting that the N-terminal region of this protein is an essential element in the architecture of the terminal organelle. Separately, the analysis of mg317(-) mutants indicates that MG317 protein is involved in the formation of the terminal button and contributes to anchoring the electron-dense core to the cell membrane. The results presented here clearly show that MG218 and MG317 proteins are implicated in the maintenance of gliding motility and cytadherence in M. genitalium.

  19. Periodicity in Attachment Organelle Revealed by Electron Cryotomography Suggests Conformational Changes in Gliding Mechanism of Mycoplasma pneumoniae

    PubMed Central

    Kawamoto, Akihiro; Matsuo, Lisa; Kato, Takayuki; Yamamoto, Hiroki

    2016-01-01

    ABSTRACT Mycoplasma pneumoniae, a pathogenic bacterium, glides on host surfaces using a unique mechanism. It forms an attachment organelle at a cell pole as a protrusion comprised of knoblike surface structures and an internal core. Here, we analyzed the three-dimensional structure of the organelle in detail by electron cryotomography. On the surface, knoblike particles formed a two-dimensional array, albeit with limited regularity. Analyses using a nonbinding mutant and an antibody showed that the knoblike particles correspond to a naplike structure that has been observed by negative-staining electron microscopy and is likely to be formed as a complex of P1 adhesin, the key protein for binding and gliding. The paired thin and thick plates feature a rigid hexagonal lattice and striations with highly variable repeat distances, respectively. The combination of variable and invariant structures in the internal core and the P1 adhesin array on the surface suggest a model in which axial extension and compression of the thick plate along a rigid thin plate is coupled with attachment to and detachment from the substrate during gliding. PMID:27073090

  20. Cell surface differentiation of Mycoplasma mobile visualized by surface protein localization.

    PubMed

    Kusumoto, Akiko; Seto, Shintaro; Jaffe, Jacob D; Miyata, Makoto

    2004-12-01

    Mycoplasma mobile has a flask-shaped cell morphology and glides toward its tapered end at a rate of 3-7 cell lengths per s (2.0-4.5 microm s(-1)) by an unknown mechanism. Gliding requires that the surface of the cell is in contact with a solid substrate, such as glass or plastic. In order to characterize the nature of the outer surface of M. mobile, monoclonal antibodies were raised against intact cells and screened for their ability to recognize surface proteins. Four antibodies were identified and their protein targets were determined. One antibody recognized the Gli349 protein, which is known to be involved in glass binding and gliding. This antibody was also able to displace attached M. mobile cells from glass, suggesting that Gli349 is the major adhesion protein in M. mobile. The other three antibodies recognized members of the Mvsp family of proteins, which are presumably the major surface antigens of M. mobile. Immunofluorescence studies were performed to localize these proteins on the surface of M. mobile cells. Gli349 localized to the proximal region of the tapered part of the cell (the 'neck'), while the various Mvsp family members showed several distinct patterns of subcellular localization. MvspN and MvspO localized to the distal end of the tapered part of the cell (the 'head'), MvspK localized to the main part of the cell (the 'body'), and MvspI localized to both the head and body but not the neck. This analysis shows that M. mobile surprisingly expresses multiple versions of its major surface antigen at once but differentiates its surface by differential localization of the various paralogues.

  1. In vivo ultrasound measurement of posterior femoral glide during hip joint mobilization in healthy college students.

    PubMed

    Loubert, Peter V; Zipple, J Tim; Klobucher, Michael J; Marquardt, Eric D; Opolka, Matthew J

    2013-08-01

    Descriptive study. To measure femoral translational glide in vivo during posterior hip joint mobilization and to interpret data in the context of the normal arthrokinematic glide necessary for hip flexion. Joint play, or translational glide available at a joint, is largely influenced by the geometry of the articular surfaces. The high degree of congruence between the articular surfaces at the hip and the substantial arc of concavity of the acetabulum suggests that the amount of translational glide available at the hip should be very small. Twenty subjects received manual posteriorly directed hip mobilization at a force equal to 50% of their body weight, while concurrent ultrasound imaging of the joint was performed. Images were captured before and during application of the target mobilization force. Femoroacetabular distance for each image was measured, and the average of the 3 greatest differences between corresponding before/during mobilization values represented the translational glide produced. The amplitude of arthrokinematic glide (tangential glide) was calculated using the measured femoral head radius and hip flexion passive range of motion for each subject. The average posterior femoral translational glide was 2.0 mm (range, 0.8-4.2 mm). The average calculated tangential glide required for hip flexion passive range of motion was 53.8 mm (range, 43.2-64.8 mm). The average translational glide as a percentage of tangential glide was 3.8% (range, 1.5%-7.9%). Translational glides at the hip are small, particularly in the context of the amplitude of glide necessary for normal hip flexion range of motion.

  2. Molecular shape and binding force of Mycoplasma mobile's leg protein Gli349 revealed by an AFM study

    SciTech Connect

    Lesoil, Charles; Nonaka, Takahiro; Sekiguchi, Hiroshi; Osada, Toshiya; Miyata, Makoto; Afrin, Rehana; Ikai, Atsushi

    2010-01-15

    Recent studies of the gliding bacteria Mycoplasma mobile have identified a family of proteins called the Gli family which was considered to be involved in this novel and yet fairly unknown motility system. The 349 kDa protein called Gli349 was successfully isolated and purified from the bacteria, and electron microscopy imaging and antibody experiments led to the hypothesis that it acts as the 'leg' of M. mobile, responsible for attachment to the substrate as well as for gliding motility. However, more precise evidence of the molecular shape and function of this protein was required to asses this theory any further. In this study, an atomic force microscope (AFM) was used both as an imaging and a force measurement device to provide new information about Gli349 and its role in gliding motility. AFM images of the protein were obtained revealing a complex structure with both rigid and flexible parts, consistent with previous electron micrographs of the protein. Single-molecular force spectroscopy experiments were also performed, revealing that Gli349 is able to specifically bind to sialyllactose molecules and withstand unbinding forces around 70 pN. These findings strongly support the idea that Gli349 is the 'leg' protein of M. mobile, responsible for binding and also most probably force generation during gliding motility.

  3. Molecular shape and binding force of Mycoplasma mobile's leg protein Gli349 revealed by an AFM study.

    PubMed

    Lesoil, Charles; Nonaka, Takahiro; Sekiguchi, Hiroshi; Osada, Toshiya; Miyata, Makoto; Afrin, Rehana; Ikai, Atsushi

    2010-01-15

    Recent studies of the gliding bacteria Mycoplasma mobile have identified a family of proteins called the Gli family which was considered to be involved in this novel and yet fairly unknown motility system. The 349kDa protein called Gli349 was successfully isolated and purified from the bacteria, and electron microscopy imaging and antibody experiments led to the hypothesis that it acts as the "leg" of M. mobile, responsible for attachment to the substrate as well as for gliding motility. However, more precise evidence of the molecular shape and function of this protein was required to asses this theory any further. In this study, an atomic force microscope (AFM) was used both as an imaging and a force measurement device to provide new information about Gli349 and its role in gliding motility. AFM images of the protein were obtained revealing a complex structure with both rigid and flexible parts, consistent with previous electron micrographs of the protein. Single-molecular force spectroscopy experiments were also performed, revealing that Gli349 is able to specifically bind to sialyllactose molecules and withstand unbinding forces around 70pN. These findings strongly support the idea that Gli349 is the "leg" protein of M. mobile, responsible for binding and also most probably force generation during gliding motility. Copyright 2009 Elsevier Inc. All rights reserved.

  4. Proteins P24 and P41 function in the regulation of terminal-organelle development and gliding motility in Mycoplasma pneumoniae.

    PubMed

    Hasselbring, Benjamin M; Krause, Duncan C

    2007-10-01

    Mycoplasma pneumoniae is a major cause of bronchitis and atypical pneumonia in humans. This cell wall-less bacterium has a complex terminal organelle that functions in cytadherence and gliding motility. The gliding mechanism is unknown but is coordinated with terminal-organelle development during cell division. Disruption of M. pneumoniae open reading frame MPN311 results in loss of protein P41 and downstream gene product P24. P41 localizes to the base of the terminal organelle and is required to anchor the terminal organelle to the cell body, but during cell division, MPN311 insertion mutants also fail to properly regulate nascent terminal-organelle development spatially or gliding activity temporally. We measured gliding velocity and frequency and used fluorescent protein fusions and time-lapse imaging to assess the roles of P41 and P24 individually in terminal-organelle development and gliding function. P41 was necessary for normal gliding velocity and proper spatial positioning of new terminal organelles, while P24 was required for gliding frequency and new terminal-organelle formation at wild-type rates. However, P41 was essential for P24 function, and in the absence of P41, P24 exhibited a dynamic localization pattern. Finally, protein P28 requires P41 for stability, but analysis of a P28(-) mutant established that the MPN311 mutant phenotype was not a function of loss of P28.

  5. "Mycoplasmal antigen modulation," a novel surface variation suggested for a lipoprotein specifically localized on Mycoplasma mobile.

    PubMed

    Wu, Heng Ning; Kawaguchi, Chie; Nakane, Daisuke; Miyata, Makoto

    2012-05-01

    Mycoplasma mobile, a pathogen of freshwater fish, glides easily across surfaces, colonizes on the fish gill, and causes necrosis. The cell surface is differentiated into three parts: the head, neck, and body. Mobile variable surface proteins (Mvsps) localizing at each of these parts may be involved in surface variation including phase variation and antigenic variation, although no proof exists. In this study, we examined this possibility by focusing on MvspI, the largest Mvsp. Immunofluorescence microscopy showed that MvspI is expressed on the surfaces of all cells. When anti-MvspI antibody was added at concentrations over 0.8 nM, MvspI was observed to decrease over time. After 72 h of cultivation with the antibody, the fluorescence intensity and amount of MvspI decreased up to 13 and 39%, respectively, compared to those of cells grown without antibody. These changes were reversed by the removal of the antibody. Such effects were not observed when another antibody targeting other Mvsps was used, suggesting that the decrease is specific to the relationship between MvspI and the antibody. Cell growth was also inhibited by the antibody, but the decrease in MvspI could not be explained by the selective growth of MvspI-negative variants or by the inhibition of growth with other conditions. The decrease in MvspI caused by the antibody binding may suggest a novel type of surface variation, designated here as "mycoplasmal antigen modulation."

  6. Toward single molecule detection of staphylococcal enterotoxin B: mobile sandwich immunoassay on gliding microtubules.

    PubMed

    Soto, Carissa M; Martin, Brett D; Sapsford, Kim E; Blum, Amy Szuchmacher; Ratna, Banahalli R

    2008-07-15

    An immunoassay based on gliding microtubules (MTs) is described for the detection of staphylococcal enterotoxin B. Detection is performed in a sandwich immunoassay format. Gliding microtubules carry the antigen-specific "capture" antibody, and bound analyte is detected using a fluorescent viral scaffold as the tracer. A detailed modification scheme for the MTs postpolymerization is described along with corresponding quantification by fluorescence spectroscopy. The resultant antibody-MTs maintain their morphology and gliding capabilities. We report a limit of detection down to 0.5 ng/mL during active transport in a 30 min assay time and down to 1 ng/mL on static surfaces. This study demonstrates the kinesin/MT-mediated capture, transport, and detection of the biowarfare agent SEB in a microfluidic format.

  7. A major determinant for gliding motility in Mycoplasma genitalium: the interaction between the terminal organelle proteins MG200 and MG491.

    PubMed

    Martinelli, Luca; Lalli, Daniela; García-Morales, Luis; Ratera, Mercè; Querol, Enrique; Piñol, Jaume; Fita, Ignacio; Calisto, Bárbara M

    2015-01-16

    Several mycoplasmas, such as the emergent human pathogen Mycoplasma genitalium, developed a complex polar structure, known as the terminal organelle (TO), responsible for a new type of cellular motility, which is involved in a variety of cell functions: cell division, adherence to host cells, and virulence. The TO cytoskeleton is organized as a multisubunit dynamic motor, including three main ultrastructures: the terminal button, the electrodense core, and the wheel complex. Here, we describe the interaction between MG200 and MG491, two of the main components of the TO wheel complex that connects the TO with the cell body and the cell membrane. The interaction between MG200 and MG491 has a KD in the 80 nm range, as determined by surface plasmon resonance. The interface between the two partners was confined to the "enriched in aromatic and glycine residues" (EAGR) box of MG200, previously described as a protein-protein interaction domain, and to a 25-residue-long peptide from the C-terminal region of MG491 by surface plasmon resonance and NMR spectroscopy studies. An atomic description of the MG200 EAGR box binding surface was also provided by solution NMR. An M. genitalium mutant lacking the MG491 segment corresponding to the peptide reveals specific alterations in cell motility and cell morphology indicating that the MG200-MG491 interaction plays a key role in the stability and functioning of the TO.

  8. Changes in kinetic, kinematic, and temporal parameters of walking in people with limited ankle dorsiflexion: pre-post application of modified mobilization with movement using talus glide taping.

    PubMed

    Yoon, Ji-yeon; Hwang, Young-in; An, Duk-hyun; Oh, Jae-seop

    2014-06-01

    The purpose of this study was to investigate the changes in passive ankle dorsiflexion range of motion (ROM), maximum plantar force, force-time integral, and time to heel off during walking between pre- and postapplication of modified mobilization with movement (MWM) using talus glide taping in people with limited ankle dorsiflexion. Eighteen feet with limited ankle dorsiflexion in 13 people were examined. Participants performed 3 different walking tasks in the following order: walking before and immediately after applying the modified MWM using talus glide taping and walking after 5-minute walking with the modified MWM using talus glide taping. A floor-mat pressure measurement system (HR-mat) was used to measure maximum plantar force, force-time integral, and time to heel off; and passive ankle dorsiflexion ROM was measured using a standard goniometer. The significance of differences was assessed using repeated one-way analysis of variance. Passive ankle dorsiflexion ROM and time to heel off were significantly increased after 5-minute walking with the modified MWM using talus glide taping compared with walking before and immediately after applying the tape. Significantly increased maximum plantar force and force-time integral on the hindfoot and significantly decreased force-time integral on the forefoot during walking after 5-minute walking were observed with the modified MWM using talus glide taping compared with before applying the tape. No significant difference between before and immediately after applying the tape was observed in any variable. Our results suggest that walking an additional 5-minute with the modified MWM using talus glide taping increased passive ankle dorsiflexion ROM and time to heel off and improved dynamic plantar loading during walking. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  9. Comparison of mulligan sustained natural apophyseal glides and maitland mobilizations for treatment of cervicogenic dizziness: a randomized controlled trial.

    PubMed

    Reid, Susan A; Rivett, Darren A; Katekar, Michael G; Callister, Robin

    2014-04-01

    There is short-term evidence for treatment of cervicogenic dizziness with Mulligan sustained natural apophyseal glides (SNAGs) but no evidence for treatment with Maitland mobilizations. The purpose of this study was to compare the effectiveness of SNAGs and Maitland mobilizations for cervicogenic dizziness. A double-blind, parallel-arm randomized controlled trial was conducted. The study was conducted at a university in Newcastle, Australia. Eighty-six people with cervicogenic dizziness were the study participants. Included participants were randomly allocated to receive 1 of 3 interventions: Mulligan SNAGs (including self-administered SNAGs), Maitland mobilizations plus range-of-motion exercises, or placebo. The primary outcome measure was intensity of dizziness. Other outcome measures were: frequency of dizziness, the Dizziness Handicap Inventory (DHI), intensity of pain, and global perceived effect (GPE). Both manual therapy groups had reduced dizziness intensity and frequency posttreatment and at 12 weeks compared with baseline. There was no change in the placebo group. Both manual therapy groups had less dizziness intensity posttreatment (SNAGs: mean difference=-20.7, 95% confidence interval [95% CI]=-33.6, -7.7; mobilizations: mean difference=-15.2, 95% CI=-27.9, -2.4) and at 12 weeks (SNAGs: mean difference=-18.4, 95% CI=-31.3, -5.4; mobilizations: mean difference=-14.4, 95% CI=-27.4, -1.5) compared with the placebo group. Compared with the placebo group, both the SNAG and Maitland mobilization groups had less frequency of dizziness at 12 weeks. There were no differences between the 2 manual therapy interventions for these dizziness measures. For DHI and pain, all 3 groups improved posttreatment and at 12 weeks. Both manual therapy groups reported a higher GPE compared with the placebo group. There were no treatment-related adverse effects lasting longer than 24 hours. The therapist performing the interventions was not blind to group allocation. Both SNAGs

  10. EMG activity of selected rotator cuff musculature during grade III distraction and posterior glide glenohumeral mobilization: results of a pilot trial comparing painful and non-painful shoulders

    PubMed Central

    Swanson, Brian T.; Holst, Brian; Infante, John; Poenitzsch, James; Ortiz, Alexis

    2016-01-01

    Objectives The objectives of this pilot study were to investigate rotator cuff activity that may be present during grade III distraction and posterior glide mobilization of the glenohumeral (GH) joint, as well as to examine any differences in response between painful and non-painful shoulders utilizing these techniques. Methods EMG data were collected using Delsys EMGworks® software and Trigno® mini-wireless electrodes for the supraspinatus, infraspinatus and upper trapezius musculature during grade III GH distraction and posterior glide mobilization. A total of 20 shoulders (10 painful, 10 non-painful) were recruited from a sample of convenience. Submaximal voluntary dynamic contraction against gravity was used as reference for each of the three selected muscles. Participants underwent two trials of each mobilization, and the mean results for each group were assessed using descriptive statistics (mean, standard deviation) and effect size. Results Both the painful and non-painful groups exhibited considerable levels of rotator cuff activity during each test parameter, with the painful group consistently generating higher supraspinatus and infraspinatus RMS and peak force activity. Analysis of the peak combined rotator cuff activity during distraction (d = 0.58) and posterior glides (d = 0.64) suggests moderate-to-high practical significance of the results. Discussion GH distraction and posterior glide mobilizations have traditionally been thought of as passive treatment procedures. The results of this pilot study indicate that the supraspinatus and infraspinatus are significantly active during these techniques. Findings suggest that during these techniques, the total infra/supraspinatus EMG activity approaches the level produced while raising the arm against gravity. Level of evidence: 2b PMID:27252577

  11. Strain on the repaired supraspinatus tendon during manual traction and translational glide mobilization on the glenohumeral joint: a cadaveric biomechanics study.

    PubMed

    Muraki, Takayuki; Aoki, Mitsuhiro; Uchiyama, Eiichi; Miyasaka, Tomoya; Murakami, Gen; Miyamoto, Shigenori

    2007-08-01

    There has been no report on the mechanical effects of joint mobilization on rotator cuffs. The purpose of this study was to determine whether it is safe to use grade 3 joint mobilization techniques after rotator cuff repair. Nine fresh frozen cadaveric shoulders were used in this study. The strains on the artificially repaired supraspinatus tendon during joint mobilization were measured at 0 degrees and 30 degrees of shoulder abduction and were compared with those at the maximal stretching position and relaxing position. Additionally, gap distances were measured during this experiment. The strain at 30 degrees of abduction of the repaired tendon during each joint mobilization was significantly smaller than that at 0 degrees abduction (P<0.05). At 30 degrees of abduction, the strain during joint mobilization was not statistically different from that of the shoulder in the relaxing position, except during the inferior glide technique. Gap distances were 0mm at 30 degrees , while the distances were 1.06-1.46 mm at 0 degrees. Our findings suggest that joint mobilization techniques, except inferior glide, can be performed safely without significantly straining the repaired tendon at 30 degrees of abduction, if rotator cuff repair is performed at 0 degrees of abduction.

  12. Molecular Structure of Isolated MvspI, a Variable Surface Protein of the Fish Pathogen Mycoplasma mobile

    PubMed Central

    Adan-Kubo, Jun; Yoshii, Shu-hei; Kono, Hidetoshi

    2012-01-01

    Mycoplasma mobile is a parasitic bacterium that causes necrosis in the gills of freshwater fishes. This study examines the molecular structure of its variable surface protein, MvspI, whose open reading frame encodes 2,002 amino acids. MvspI was isolated from mycoplasma cells by a biochemical procedure to 92% homogeneity. Gel filtration and analytical ultracentrifugation suggested that this protein is a cylinder-shaped monomer with axes of 66 and 2.7 nm. Rotary shadowing transmission electron microscopy of MvspI showed that the molecule is composed of two rods 30 and 45 nm long; the latter rod occasionally features a bulge. Immuno-electron microscopy and epitope mapping showed that the bulge end of the molecular image corresponds to the C terminus of the amino acid sequence. Partial digestion by various proteases suggested that the N-terminal part, comprised of 697 amino acids, is flexible. Analysis of the predicted amino acid sequence showed that the molecule features a lipoprotein and 16 repeats of about 90 residues; 15 positions exist between residues 88 and 1479, and the other position is between residues 1725 and 1807. The amino acid sequence of MvspI was mapped onto a molecular image obtained by electron microscopy. The present study is the first to elucidate the molecular shape of a variable surface protein of mycoplasma. PMID:22447898

  13. Cervical Lateral Glide Neural Mobilization Is Effective in Treating Cervicobrachial Pain: A Randomized Waiting List Controlled Clinical Trial.

    PubMed

    Rodríguez-Sanz, David; Calvo-Lobo, César; Unda-Solano, Francisco; Sanz-Corbalán, Irene; Romero-Morales, Carlos; López-López, Daniel

    2017-03-13

     Cervicobrachial pain (CP) is a high-incidence and prevalent condition. Cervical lateral glide (CLG) is a firstline treatment of CP. There is a current lack of enough high-quality randomized controlled double-blind clinical trials that measure the effectiveness of neural tissue mobilization techniques such as the CLG and its specific effect over CP.  The aim of the present study was to assess the effect of CLG neural mobilization in treating subjects who suffer from CP, compared with the complete absence of treatment.  This investigation was a single-center, blinded, parallel randomized controlled clinical trial (RCT).  One hundred forty-seven individuals were screened in a medical center from July to November 2015. Fifty-eight participants were diagnosed with CP.  Participants were recruited and randomly assigned into two groups of 29 subjects. The intervention group received CLG treatment, and the control group (CG) was assigned to a six-week waiting list to receive treatment. Randomization was carried out by concealed computer software randomized printed cards. The primary outcome was pain intensity, reported through the Numeric Rating Scale for Pain (NRSP). Secondary outcomes were physical function involving the affected upper limb using the Quick DASH scale and ipsilateral cervical rotation (ICR) using a CROM device. Assessments were made at baseline and one hour after treatment.  The CLG group NRSP mean value was significantly ( P  < 0.0001) superior to those obtained by the CG. Subjects treated with CLG reported an average NRSP decrease of 2.16 points (35%). CROM device and Quick DASH outcome values also reported significant ( P < 0.0001) improvements only in the CLG group. Cohen's d showed a very large effect of the CLG intervention at subject discharge.  Due to the lack of dipper subgroup analysis and additional reproductions of the applied protocol, the authors considered the generalization of the study results to be impossible.

  14. The effects of posterior talar glide with dorsiflexion of the ankle on mobility, muscle strength and balance in stroke patients: a randomised controlled trial

    PubMed Central

    Lee, Jin; Kim, Ju-O; Lee, Byoung-Hee

    2017-01-01

    [Purpose] The purpose of this study was to examine the effectiveness of posterior talar glide (PTG) with dorsiflexion of the ankle on stroke patients ankle mobility, muscle strength, and balance ability. [Subjects and Methods] Thirty-four subjects were randomly assigned to either a PTG with dorsiflexion group (PTG; n=17), or a weight-bearing with placebo PTG group (control; n=17). Subjects in the PTG group performed PTG with dorsiflexion, designed to improve ankle mobility, muscle strength and balance ability with proprioceptive control of the ankle, for 10 glides of 5 sets/day, 5 days/week, for 4 weeks. [Results] The experimental group showed significant improvement on the Ankle Dorsiflexion Range of Motion assessment, Ankle Dorsiflexor Manual Muscle Test, Functional Reach Test, Time Up and Go test, and Functional Gait Assessment compared to the control group. However, regarding Ankle Plantarflexion Range of Motion assessment and the Ankle Plantarflexor Manual Muscle Test, no significant differences were found between the two groups. [Conclusion] The results of this study show that PTG with dorsiflexion can improve ankle mobility, muscle strength and balance ability in patients recovering from stroke. This exercise may prove useful in clinical rehabilitation. Further research on the long-term effectiveness of PTG on gait ability is suggested. PMID:28356629

  15. Performance analysis of jump-gliding locomotion for miniature robotics.

    PubMed

    Vidyasagar, A; Zufferey, Jean-Christohphe; Floreano, Dario; Kovač, M

    2015-03-26

    Recent work suggests that jumping locomotion in combination with a gliding phase can be used as an effective mobility principle in robotics. Compared to pure jumping without a gliding phase, the potential benefits of hybrid jump-gliding locomotion includes the ability to extend the distance travelled and reduce the potentially damaging impact forces upon landing. This publication evaluates the performance of jump-gliding locomotion and provides models for the analysis of the relevant dynamics of flight. It also defines a jump-gliding envelope that encompasses the range that can be achieved with jump-gliding robots and that can be used to evaluate the performance and improvement potential of jump-gliding robots. We present first a planar dynamic model and then a simplified closed form model, which allow for quantification of the distance travelled and the impact energy on landing. In order to validate the prediction of these models, we validate the model with experiments using a novel jump-gliding robot, named the 'EPFL jump-glider'. It has a mass of 16.5 g and is able to perform jumps from elevated positions, perform steered gliding flight, land safely and traverse on the ground by repetitive jumping. The experiments indicate that the developed jump-gliding model fits very well with the measured flight data using the EPFL jump-glider, confirming the benefits of jump-gliding locomotion to mobile robotics. The jump-glide envelope considerations indicate that the EPFL jump-glider, when traversing from a 2 m height, reaches 74.3% of optimal jump-gliding distance compared to pure jumping without a gliding phase which only reaches 33.4% of the optimal jump-gliding distance. Methods of further improving flight performance based on the models and inspiration from biological systems are presented providing mechanical design pathways to future jump-gliding robot designs.

  16. Mycoplasma viruses.

    PubMed

    Maniloff, J

    1988-01-01

    Unlike bacterial viruses that infect cells bounded by a cell wall, mycoplasma viruses have evolved to enter and propagate in mycoplasma cells bounded only by a single lipid-protein cell membrane. In addition, mycoplasmas have the smallest amount of genetic information of any known cells, so their complexity is constrained by a limited genetic coding capacity. As a consequence of these host cell differences, mycoplasma viruses have been found to have a variety of structures and replication strategies which are different from those of the bacterial viruses. This article is a critical review of mycoplasma viruses infecting the genera Acholeplasma, Spiroplasma, and Mycoplasma; included are data on classification, morphology and structure, biological and physical properties, chemical composition, and productive and lysogenic replication cycles.

  17. Dynamics of glide avalanches and snow gliding

    NASA Astrophysics Data System (ADS)

    Ancey, Christophe; Bain, Vincent

    2015-09-01

    In recent years, due to warmer snow cover, there has been a significant increase in the number of cases of damage caused by gliding snowpacks and glide avalanches. On most occasions, these have been full-depth, wet-snow avalanches, and this led some people to express their surprise: how could low-speed masses of wet snow exert sufficiently high levels of pressure to severely damage engineered structures designed to carry heavy loads? This paper reviews the current state of knowledge about the formation of glide avalanches and the forces exerted on simple structures by a gliding mass of snow. One particular difficulty in reviewing the existing literature on gliding snow and on force calculations is that much of the theoretical and phenomenological analyses were presented in technical reports that date back to the earliest developments of avalanche science in the 1930s. Returning to these primary sources and attempting to put them into a contemporary perspective are vital. A detailed, modern analysis of them shows that the order of magnitude of the forces exerted by gliding snow can indeed be estimated correctly. The precise physical mechanisms remain elusive, however. We comment on the existing approaches in light of the most recent findings about related topics, including the physics of granular and plastic flows, and from field surveys of snow and avalanches (as well as glaciers and debris flows). Methods of calculating the forces exerted by glide avalanches are compared quantitatively on the basis of two case studies. This paper shows that if snow depth and density are known, then certain approaches can indeed predict the forces exerted on simple obstacles in the event of glide avalanches or gliding snow cover.

  18. Longitudinal Gliding of the Median Nerve in the Carpal Tunnel: Ultrasound Cadaveric Evaluation of Conventional and Novel Concepts of Nerve Mobilization.

    PubMed

    Meng, Stefan; Reissig, Lukas F; Beikircher, Reinhard; Tzou, Chieh-Han John; Grisold, Wolfgang; Weninger, Wolfgang J

    2015-12-01

    To evaluate median nerve excursion during conventional nerve gliding exercises and newly developed exercises, primarily comprising abduction and adduction of the fingers. Descriptive study. Anatomical dissection facility. Random sample of upper extremities of fresh whole-body human cadavers (N=18). Cadavers with neuromuscular diseases in the medical record or anatomic variations were excluded. Conventional and new nerve gliding exercises. Distances between markers applied into the nerve and markers in the periosteum were visualized with ultrasound and measured. Comparisons of nerve excursions between different exercises were performed. Conventional exercises led to substantial nerve gliding proximal to the carpal tunnel and between the head of the pronator teres (12 and 13.8mm, respectively), but it led to far less in the carpal tunnel (6.6mm). With our novel exercises, we achieved nerve gliding in the carpal tunnel of 13.8mm. No substantial marker movement could be detected during lateral flexion of the cervical spine. Although conventional nerve gliding exercises only lead to minimal nerve excursions in the carpal tunnel, our novel exercises with the abduction and adduction of the fingers result in substantial longitudinal gliding throughout the arm. Clinical trials will have to deliver the clinical evidence. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. Motility of Mycoplasma pneumoniae.

    PubMed Central

    Radestock, U; Bredt, W

    1977-01-01

    Cell of Mycoplasma pneumoniae FH gliding on a glass surface in liquid medium were examined by microscopic observation and quantitatively by microcinematography (30 frames per min). Comparisons were made only within the individual experiments. The cells moved in an irregular pattern with numerous narrow bends and circles. They never changed their leading end. The average speed (without pauses) was relatively constant between o.2 and 0.5 mum/s. The maximum speed was about 1.5 to 2.0 mum/s. The movements were interrupted by resting periods of different lengths and frequency. Temperature, viscosity, pH, and the presence of yeast extract in the medium influenced the motility significantly; changes in glucose, calcium ions, and serum content were less effective. The movements were affected by iodoacetate, p-mercuribenzoate, and mitomycin C at inhibitory or subinhibitory concentrations. Sodium fluoride, sodium cyanide, dinitrophenol, chloramphenicol, puromycin, cholchicin, and cytochalasin B at minimal inhibitory concentrations did not affect motility. The movements were effectively inhibited by anti-M. pneumoniae antiserum. Studies with absorbed antiserum suggested that the surface components involved in motility are heat labile. The gliding of M. pneumoniae cells required an intact energy metabolism and the proteins involved seemed to have a low turnover. Images PMID:14925

  20. New gliding mammaliaforms from the Jurassic.

    PubMed

    Meng, Qing-Jin; Grossnickle, David M; Liu, Di; Zhang, Yu-Guang; Neander, April I; Ji, Qiang; Luo, Zhe-Xi

    2017-08-17

    Stem mammaliaforms are Mesozoic forerunners to mammals, and they offer critical evidence for the anatomical evolution and ecological diversification during the earliest mammalian history. Two new eleutherodonts from the Late Jurassic period have skin membranes and skeletal features that are adapted for gliding. Characteristics of their digits provide evidence of roosting behaviour, as in dermopterans and bats, and their feet have a calcaneal calcar to support the uropagatium as in bats. The new volant taxa are phylogenetically nested with arboreal eleutherodonts. Together, they show an evolutionary experimentation similar to the iterative evolutions of gliders within arboreal groups of marsupial and placental mammals. However, gliding eleutherodonts possess rigid interclavicle-clavicle structures, convergent to the avian furculum, and they retain shoulder girdle plesiomorphies of mammaliaforms and monotremes. Forelimb mobility required by gliding occurs at the acromion-clavicle and glenohumeral joints, is different from and convergent to the shoulder mobility at the pivotal clavicle-sternal joint in marsupial and placental gliders.

  1. New gliding mammaliaforms from the Jurassic

    NASA Astrophysics Data System (ADS)

    Meng, Qing-Jin; Grossnickle, David M.; Liu, Di; Zhang, Yu-Guang; Neander, April I.; Ji, Qiang; Luo, Zhe-Xi

    2017-08-01

    Stem mammaliaforms are Mesozoic forerunners to mammals, and they offer critical evidence for the anatomical evolution and ecological diversification during the earliest mammalian history. Two new eleutherodonts from the Late Jurassic period have skin membranes and skeletal features that are adapted for gliding. Characteristics of their digits provide evidence of roosting behaviour, as in dermopterans and bats, and their feet have a calcaneal calcar to support the uropagatium as in bats. The new volant taxa are phylogenetically nested with arboreal eleutherodonts. Together, they show an evolutionary experimentation similar to the iterative evolutions of gliders within arboreal groups of marsupial and placental mammals. However, gliding eleutherodonts possess rigid interclavicle-clavicle structures, convergent to the avian furculum, and they retain shoulder girdle plesiomorphies of mammaliaforms and monotremes. Forelimb mobility required by gliding occurs at the acromion-clavicle and glenohumeral joints, is different from and convergent to the shoulder mobility at the pivotal clavicle-sternal joint in marsupial and placental gliders.

  2. The bacterial gliding machinery

    NASA Astrophysics Data System (ADS)

    Shrivastava, Abhishek

    Cells of Flavobacterium johnsoniae, a rod-shaped bacterium, glide over surfaces with speeds reaching up to 2 micrometer's. Gliding is powered by a protonmotive force. The adhesin SprB forms filaments about 160 nm long that move on the cell-surface along a looped track. Interaction of SprB filaments with a surface produces gliding. We tethered F. johnsoniae cells to glass by adding anti-SprB antibody. Tethered cells spun about fixed points, rotating at speeds of about 1 Hz. The torques required to sustain such speeds were large, comparable to those generated by the flagellar rotary motor. Using a flow cell apparatus, we changed load on the gliding motor by adding the viscous agent Ficoll to tethered cells. We found that a gliding motor runs at constant speed rather than constant torque. We attached gold nanoparticles to the SprB filament and tracked its motion. We fluorescently tagged a bacterial Type IX secretion system (T9SS) protein and imaged its dynamics. Fluorescently tagged T9SS protein localized near the point of tether, indicating that T9SS localizes with the gliding motor. Based on our results, we propose a model to explain bacterial gliding.

  3. How myxobacteria glide

    NASA Astrophysics Data System (ADS)

    Wolgemuth, Charles; Hoiczyk, Egbert; Oster, George; Kaiser, Dale

    2002-03-01

    Many bacteria, including myxobacteria and cyanobacteria, move by gliding. Although gliding always describes a slow surface-associated translocation in the direction of the cell's long axis, it can result from two distinct mechanisms: social (S) motility and adventurous (A) motility. The force for S-motility is generated by type IV pili but the mechanism driving A-motility has remained a mystery. We propose a model based on recent EM and light microscopic data that A-motility is generated by the secretion and hydration of slime, a polyelectrolyte gel. We derive a physical model for gel hydration and show that it produces sufficient force to drive gliding motility in bacteria. As well, we also provide further experimental evidence that slime extrusion is the proulsive mechanism for A-type motility.

  4. First identification of proteins involved in motility of Mycoplasma gallisepticum.

    PubMed

    Indikova, Ivana; Vronka, Martin; Szostak, Michael P

    2014-10-17

    Mycoplasma gallisepticum, the most pathogenic mycoplasma in poultry, is able to glide over solid surfaces. Although this gliding motility was first observed in 1968, no specific protein has yet been shown to be involved in gliding. We examined M. gallisepticum strains and clonal variants for motility and found that the cytadherence proteins GapA and CrmA were required for gliding. Loss of GapA or CrmA resulted in the loss of motility and hemadsorption and led to drastic changes in the characteristic flask-shape of the cells. To identify further genes involved in motility, a transposon mutant library of M. gallisepticum was generated and screened for motility-deficient mutants, using a screening assay based on colony morphology. Motility-deficient mutants had transposon insertions in gapA and the neighbouring downstream gene crmA. In addition, insertions were seen in gene mgc2, immediately upstream of gapA, in two motility-deficient mutants. In contrast to the GapA/CrmA mutants, the mgc2 motility mutants still possessed the ability to hemadsorb. Complementation of these mutants with a mgc2-hexahistidine fusion gene restored the motile phenotype. This is the first report assigning specific M. gallisepticum proteins to involvement in gliding motility.

  5. Hang-gliding accidents.

    PubMed Central

    Margreiter, R; Lugger, L J

    1978-01-01

    Seventy-five known hang-gliding accidents causing injury to the pilot occurred in the Tyrol during 1973-6. Most occurred in May, June, or September and between 11 am and 3 pm, when unfavourable thermic conditions are most likely. Thirty-four accidents happened during launching, 13 during flight, and 28 during landing, and most were caused by human errors--especially deficient launching technique; incorrect estimation of wind conditions, altitude, and speed; and choice of unfavourable launching and landing sites. Eight pilots were moderately injured, 60 severely (multiply in 24 cases), and seven fatally; fractures of the spine and arms predominated. Six of the 21 skull injuries were fatal. The risk of hang-gliding seems unjustifiably high, and safety precautions and regulations should be adopted to ensure certain standards of training and equipment and to limit flying to favourable sites and times. Images p401-a PMID:624028

  6. On Dislocation Glide in Planetary Interiors

    NASA Astrophysics Data System (ADS)

    Cordier, P.; Carrez, P.; Gouriet, K.; Kraych, A.; Ritterbex, S.

    2015-12-01

    The dynamics of hot planets depends strongly on how heat is transported to their surfaces through large scale convection flows. This is ultimately controlled by the rheology of high-pressure phases under extreme conditions. Whenever solid rocks are concerned, plastic flow results from the propagation of crystal defects (point defects, dislocations, grain boundaries). In this presentation we focus on the role of pressure on dislocation glide which is usually the most efficient strain-producing mechanism. Dislocation glide is assessed through multiscale numerical modeling. First, dislocations are modeled at the atomic scale based on first-principles calculations to incorporate the influence of pressure. Then the mobility law of dislocation at finite temperature is modeled by describing thermally-activated mechanisms for dislocation glide based on the kink-pair model. Then the flow stress at the grain scale is deduced either from application of the Orowan equation or by dislocation dynamics modeling. This approach is applied to wadsleyite, ringwoodite, bridgmanite and post-perovskite. Mechanical properties are either calculated at laboratory strain-rates to be compared with experiments when available or at mantle strain-rate to assess their efficiency under natural conditions.

  7. [Pathogenic factors of mycoplasma].

    PubMed

    Shimizu, Takashi

    2015-01-01

    Mycoplasmas are smallest organisms capable of self-replication and cause various diseases in human. Especially, Mycoplasma pneumoniae is known as an etiological agent of pneumonia. From 2010 to 2012, epidemics of M. pneumoniae infections were reported worldwide (e.g., in France, Israel, and Japan). In the diseases caused by mycoplasmas, strong inflammatory responses induced by mycoplasmas have been thought to be important. However, mycoplasmas lack of cell wall and do not possess inflammation-inducing endotoxin such as lipopolysaccharide (LPS). We purified inflammation-inducing factors from pathogenic mycoplasmas and identified that they were lipoproteins. Lipoproteins derived from mycoplasmas induced inflammatory responses through Toll-like receptor (TLR) 2. In addition, we demonstrated that cytadherent property of M. pneumoniae played an important role in induction of inflammatory responses. Cytadherent property of M. pneumoniae induced inflammatory responses through TLR2 independent pathway. TLR4, inflammasomes, and autophagy were involved in this TLR2 independent induction of inflammatory responses.

  8. Feline hemotropic mycoplasmas.

    PubMed

    Sykes, Jane E

    2010-11-01

    Three species of hemotropic mycoplasmas are known to infect cats worldwide, Mycoplasma haemofelis, "Candidatus Mycoplasma turicensis" and "Candidatus Mycoplasma haemominutum." These organisms were previously known as Haemobartonella felis, but are now known to be mycoplasmas. Assays based on polymerase chain reaction technology are the most sensitive and specific diagnostic tests available for these organisms. M haemofelis is the most pathogenic species, and causes hemolytic anemia in immunocompetent cats. Other differential diagnoses for hemolytic anemia should be considered in cats testing positive for "Candidatus Mycoplasma turicensis" and "Candidatus Mycoplasma haemominutum," because the presence of these organisms is not always associated with anemia. Blood from infected cats should be handled with care because of the potential zoonotic nature of hemoplasma infections. The treatment of choice for cats with clinical disease is doxycycline.

  9. Hydrodynamic glide efficiency in swimming.

    PubMed

    Naemi, Roozbeh; Easson, William J; Sanders, Ross H

    2010-07-01

    The glide is a major part of starts, turns and the stroke cycle in breaststroke. Glide performance, indicated by the average velocity, can be improved by increasing the glide efficiency, that is, the ability of the body to minimise deceleration. This paper reviews the factors that affect glide efficiency. In the first part of the review the sources of resistive force are reviewed including surface friction (skin drag), pressure (form) drag and resistance due to making waves (wave drag). The effect of body surface characteristics on the skin drag, the effect of the depth of the swimmer on wave drag, and the effects of posture and alignment, body size and shape on the form drag are reviewed. The effects of these variables on the added mass, that is, the mass of water entrained with the body are explained. The 'glide factor' as a measure of glide efficiency that takes into account the combined effect of the resistive force and the added mass is described. In the second part methods of quantifying the resistive force are reviewed. Finally, the 'hydro-kinematic method' of measuring glide efficiency is evaluated.

  10. The Physics of Hang Gliding

    NASA Astrophysics Data System (ADS)

    Hewett, Lionel D.

    2008-03-01

    Dr. Hewett has received both national and international awards from the hang gliding community for his contributions to the safety of towing hang gliders. These contributions were a consequence of his applying his knowledge of physics to the sport of hang gliding. This lecture illustrates how these and other applications of the fundamental principles of physics have influenced the historical evolutions of hang gliding and paragliding from the earliest flights of Otto Lilienthal in 1891 through the more recent record breaking flights of more than 430 miles from Zapata Texas.

  11. Dissipative shocks behind bacteria gliding.

    PubMed

    Virga, Epifanio G

    2014-11-28

    Gliding is a means of locomotion on rigid substrates used by a number of bacteria, including myxobacteria and cyanobacteria. One of the hypotheses advanced to explain this motility mechanism hinges on the role played by the slime filaments continuously extruded from gliding bacteria. This paper solves, in full, a non-linear mechanical theory that treats as dissipative shocks both the point where the extruded slime filament comes into contact with the substrate, called the filament's foot, and the pore on the bacterium outer surface from where the filament is ejected. I prove that kinematic compatibility for shock propagation requires that the bacterium uniform gliding velocity (relative to the substrate) and the slime ejecting velocity (relative to the bacterium) must be equal, a coincidence that seems to have already been observed. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. Effect of triggering and entrapment on tendon gliding properties following digital flexor tendon laceration: in vitro study on turkey tendon.

    PubMed

    Kennedy, J A; Dias, J J

    2014-09-01

    The optimal management of partial flexor tendon laceration is controversial and remains a clinical challenge. Abnormal tendon gliding (triggering and entrapment) was assessed at the A2 pulley in 40 turkey tendons in three groups: intact, partially divided (palmar or lateral), and trimmed. Testing was of gliding resistance and friction coefficient at 30° and 70° of flexion, loaded with 2 and 4 N. We observed for triggering and entrapment. The changes in gliding properties were compared and analysed using Wilcoxon matched pair testing. A significant difference was found in the change in gliding properties of intact to lacerated and lacerated to trimmed tendons and between tendons that glided normally compared with those exhibiting triggering or entrapment. This suggests that palmar and lateral lacerations which, through clinical examination and visualization, are found to glide normally should be treated with early mobilization. However, partial lacerations that exhibit triggering or entrapment should be trimmed. © The Author(s) 2013.

  13. The Korean Prevocalic Palatal Glide: A Comparison with the Russian Glide and Palatalization.

    PubMed

    Suh, Yunju; Hwang, Jiwon

    2016-01-01

    Phonetic studies of the Korean prevocalic glides have often suggested that they are shorter in duration than those of languages like English, and lack a prolonged steady state. In addition, the formant frequencies of the Korean labiovelar glide are reported to be greatly influenced by the following vowel. In this study the Korean prevocalic palatal glide is investigated vis-à-vis the two phonologically similar configurations of another language - the glide /j/ and the secondary palatalization of Russian, with regard to the inherent duration of the glide component, F2 trajectory, vowel-to-glide coarticulation and glide-to-vowel coarticulation. It is revealed that the Korean palatal glide is closer to the Russian palatalization in duration and F2 trajectory, indicating a lack of steady state, and to the Russian segmental glide in the vowel-to-glide coarticulation degree. When the glide-to-vowel coarticulation is considered, the Korean palatal glide is distinguished from both Russian categories. The results suggest that both the Korean palatal glide and the Russian palatalization involve significant articulatory overlap, the former with the vowel and the latter with the consonant. Phonological implications of such a difference in coarticulation pattern are discussed, as well as the comparison between the Korean labiovelar and palatal glides.

  14. Mycoplasmas: Brain invaders?

    PubMed

    Rosales, Rubén S; Puleio, Roberto; Loria, Guido R; Catania, Salvatore; Nicholas, Robin A J

    2017-08-01

    Mycoplasmas of humans and animals are usually associated with respiratory, autoimmune, genital and joint diseases. Human mycoplasmas have also been known to affect the brain. Severe central nervous system (CNS) diseases, such as encephalitis, have been linked to Mycoplasma pneumoniae and ureaplasma infections. Less well known is the sheep and goat pathogen, Mycoplasma agalactiae, which has been found in large quantities in the brain where it may be responsible for non-purulent encephalitis as well as ataxia in young animals. Experimental intra-mammary infections of sheep with this mycoplasma have resulted in histopathological changes in the CNS. The cattle pathogen, M. bovis, has been reported occasionally in the brains of calves and adult cattle showing a range of histopathological lesions including abscesses and fibrinous meningitis. Two avian pathogens, M. gallisepticum and M. synoviae have been isolated from the brains of poultry showing meningeal vasculitis and encephalitis. There have been no reported detections of two other avian pathogens, M. meleagridis or M. iowae in the CNS. Over the last few decades, mycoplasmas have been isolated from the brains of sea mammals dying in large numbers in the North Sea although it was concluded that their role may be secondary to underlying viral disease. Finally, evidence has been advanced that certain Spiroplasma species may have a role in the development of the transmissible spongiform encephalopathies (TSE). Invasion of the brain by mycoplasmas may be as a result of direct entry following damage to the inner ear as seen with M. bovis or across the blood brain barrier by mechanisms as yet uncertain. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. [Sensory illusions in hang-gliding].

    PubMed

    Bousquet, F; Bizeau, A; Resche-Rigon, P; Taillemite, J P; De Rotalier

    1997-01-01

    Sensory illusions in hang-gliding and para-gliding. Hang-gliding and para-gliding are at the moment booming sports. Sensory illusions are physiological phenomena sharing the wrong perception of the pilote's real position in space. These phenomena are very familiar to aeroplane pilotes, they can also be noticed on certain conditions with hang-gliding pilotes. There are many and various sensory illusions, but only illusions of vestibular origin will be dealt with in this article. Vestibular physiology is reminded with the working principle of a semicircular canal. Physiology and laws of physics explain several sensory illusions, especially when the pilote loses his visual landmarks: flying through a cloud, coriolis effect. Also some specific stages of hang-gliding foster those phenomena: spiraling downwards, self-rotation, following an asymetric closing of the parachute, spin on oneself. Therefore a previous briefing for the pilotes seems necessary.

  16. Bacteria that glide with helical tracks

    PubMed Central

    Nan, Beiyan; McBride, Mark J.; Chen, Jing; Zusman, David R.; Oster, George

    2014-01-01

    Many bacteria glide smoothly on surfaces, but with no discernable propulsive organelles on their surface. Recent experiments with Myxococcus xanthus and Flavobacterium johnsoniae show that both distantly related bacterial species glide utilizing proteins that move in helical tracks, albeit with significantly different motility mechanisms. Both species utilize proton motive force for movement. However, the motors that power gliding in M. xanthus have been identified, while the F. johnsoniae motors remain to be discovered. PMID:24556443

  17. Distribution and diversity of mycoplasma plasmids: lessons from cryptic genetic elements

    PubMed Central

    2012-01-01

    Background The evolution of mycoplasmas from a common ancestor with Firmicutes has been characterized not only by genome down-sizing but also by horizontal gene transfer between mycoplasma species sharing a common host. The mechanisms of these gene transfers remain unclear because our knowledge of the mycoplasma mobile genetic elements is limited. In particular, only a few plasmids have been described within the Mycoplasma genus. Results We have shown that several species of ruminant mycoplasmas carry plasmids that are members of a large family of elements and replicate via a rolling-circle mechanism. All plasmids were isolated from species that either belonged or were closely related to the Mycoplasma mycoides cluster; none was from the Mycoplasma bovis-Mycoplasma agalactiae group. Twenty one plasmids were completely sequenced, named and compared with each other and with the five mycoplasma plasmids previously reported. All plasmids share similar size and genetic organization, and present a mosaic structure. A peculiar case is that of the plasmid pMyBK1 from M. yeatsii; it is larger in size and is predicted to be mobilizable. Its origin of replication and replication protein were identified. In addition, pMyBK1 derivatives were shown to replicate in various species of the M. mycoides cluster, and therefore hold considerable promise for developing gene vectors. The phylogenetic analysis of these plasmids confirms the uniqueness of pMyBK1 and indicates that the other mycoplasma plasmids cluster together, apart from the related replicons found in phytoplasmas and in species of the clade Firmicutes. Conclusions Our results unraveled a totally new picture of mycoplasma plasmids. Although they probably play a limited role in the gene exchanges that participate in mycoplasma evolution, they are abundant in some species. Evidence for the occurrence of frequent genetic recombination strongly suggests they are transmitted between species sharing a common host or niche. PMID

  18. Glide performance and aerodynamics of non-equilibrium glides in northern flying squirrels (Glaucomys sabrinus)

    PubMed Central

    Bahlman, Joseph W.; Swartz, Sharon M.; Riskin, Daniel K.; Breuer, Kenneth S.

    2013-01-01

    Gliding is an efficient form of travel found in every major group of terrestrial vertebrates. Gliding is often modelled in equilibrium, where aerodynamic forces exactly balance body weight resulting in constant velocity. Although the equilibrium model is relevant for long-distance gliding, such as soaring by birds, it may not be realistic for shorter distances between trees. To understand the aerodynamics of inter-tree gliding, we used direct observation and mathematical modelling. We used videography (60–125 fps) to track and reconstruct the three-dimensional trajectories of northern flying squirrels (Glaucomys sabrinus) in nature. From their trajectories, we calculated velocities, aerodynamic forces and force coefficients. We determined that flying squirrels do not glide at equilibrium, and instead demonstrate continuously changing velocities, forces and force coefficients, and generate more lift than needed to balance body weight. We compared observed glide performance with mathematical simulations that use constant force coefficients, a characteristic of equilibrium glides. Simulations with varying force coefficients, such as those of live squirrels, demonstrated better whole-glide performance compared with the theoretical equilibrium state. Using results from both the observed glides and the simulation, we describe the mechanics and execution of inter-tree glides, and then discuss how gliding behaviour may relate to the evolution of flapping flight. PMID:23256188

  19. Glide performance and aerodynamics of non-equilibrium glides in northern flying squirrels (Glaucomys sabrinus).

    PubMed

    Bahlman, Joseph W; Swartz, Sharon M; Riskin, Daniel K; Breuer, Kenneth S

    2013-03-06

    Gliding is an efficient form of travel found in every major group of terrestrial vertebrates. Gliding is often modelled in equilibrium, where aerodynamic forces exactly balance body weight resulting in constant velocity. Although the equilibrium model is relevant for long-distance gliding, such as soaring by birds, it may not be realistic for shorter distances between trees. To understand the aerodynamics of inter-tree gliding, we used direct observation and mathematical modelling. We used videography (60-125 fps) to track and reconstruct the three-dimensional trajectories of northern flying squirrels (Glaucomys sabrinus) in nature. From their trajectories, we calculated velocities, aerodynamic forces and force coefficients. We determined that flying squirrels do not glide at equilibrium, and instead demonstrate continuously changing velocities, forces and force coefficients, and generate more lift than needed to balance body weight. We compared observed glide performance with mathematical simulations that use constant force coefficients, a characteristic of equilibrium glides. Simulations with varying force coefficients, such as those of live squirrels, demonstrated better whole-glide performance compared with the theoretical equilibrium state. Using results from both the observed glides and the simulation, we describe the mechanics and execution of inter-tree glides, and then discuss how gliding behaviour may relate to the evolution of flapping flight.

  20. New model of flap-gliding flight.

    PubMed

    Sachs, Gottfried

    2015-07-21

    A new modelling approach is presented for describing flap-gliding flight in birds and the associated mechanical energy cost of travelling. The new approach is based on the difference in the drag characteristics between flapping and non-flapping due to the drag increase caused by flapping. Thus, the possibility of a gliding flight phase, as it exists in flap-gliding flight, yields a performance advantage resulting from the decrease in the drag when compared with continuous flapping flight. Introducing an appropriate non-dimensionalization for the mathematical relations describing flap-gliding flight, results and findings of generally valid nature are derived. It is shown that there is an energy saving of flap-gliding flight in the entire speed range compared to continuous flapping flight. The energy saving reaches the highest level in the lower speed region. The travelling speed of flap-gliding flight is composed of the weighted average of the differing speeds in the flapping and gliding phases. Furthermore, the maximum range performance achievable with flap-gliding flight and the associated optimal travelling speed are determined. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Use of polymerase chain reactions to detect Mycoplasma gallisepticum, Mycoplasma imitans, Mycoplasma iowae, Mycoplasma meleagridis and Mycoplasma synoviae in birds of prey.

    PubMed

    Lierz, M; Hagen, N; Lueschow, D; Hafez, H M

    2008-10-01

    Certain Mycoplasma spp. are pathogens of poultry, but little is known of the role of mycoplasmas in disease of birds of prey. Species-specific polymerase chain reactions (PCRs) for the detection of the poultry pathogens Mycoplasma gallisepticum, Mycoplasma imitans, Mycoplasma iowae, Mycoplasma meleagridis and Mycoplasma synoviae were therefore evaluated for use in birds of prey. The specificities of the PCR methods were established using avian and other mycoplasmas and also selected walled bacteria. The sensitivities of the different PCR assays varied between 100 fg and 10 pg DNA. Fifty-three tracheal swabs from healthy captive and free-ranging birds of prey were then investigated using these PCRs, and in no case was an amplicon obtained for M. gallisepticum/M. imitans, M. iowae or M. synoviae. Species-specific primers for M. meleagridis amplified a product from eight birds of prey but restriction enzyme analysis as well as sequencing of PCR products demonstrated these results to be false positives. Alignment studies of the sequenced products with the 16S rRNA gene sequence of various Mycoplasma species in GenBank demonstrated an identity of 91% to M. meleagridis but of 98% to Mycoplasma buteonis or Mycoplasma gallopavonis. Isolation and attempted identification of these mycoplasmas suggested it may be a previously unrecognized species.

  2. Mycoplasma bovis research update

    USDA-ARS?s Scientific Manuscript database

    Mycoplasma bovis in bison is a newly emerging and potentially devastating threat to the bison industry. This bacterium is increasingly being identified, both in the United States and Canada, as the cause of severe respiratory disease outbreaks with devastating consequences for the health of the ani...

  3. Mycoplasma infections of plants.

    PubMed

    Bove, J M

    1981-07-01

    Plants can be infected by two types of wall-less procaryotes, spiroplasmas and mycoplasma-like organisms (MLO), both located intracellularly in the phloem tissues of affected plants. Spiroplasmas have been cultured, characterized and shown to be true members of the class Mollicutes. MLO have not yet been cultured or characterized; they are thought to be mycoplasma-like on the basis of their ultrastructure as seen in situ, their sensitivity to tetracycline and resistance to penicillin. Mycoplasmas can also be found on the surface of plants. These extracellularly located organisms are members of the following genera: Spiroplasma. Mycoplasma and Acholeplasma. The presence of such surface mycoplasmas must not be overlooked when attempts to culture MLO from affected plants are undertaken. Sensitive serological techniques such as the enzyme-linked immunosorbent assay (ELISA) can successfully be used to compare the MLO located in the phloem of affected plants with those eventually cultured from the same plants. In California and Morocco periwinkles naturally infected with both Spiroplasma citri and MLO have been reported. With such doubly infected plants, the symptom expression has been that characteristic of the MLO disease (phyllody or stolbur), not that given by S. citri. Only S. citri can be cultured from such plants, but this does not indicate that S. citri is the causal agent of the disease expressed by the plant. In California many nonrutaceous plants have been found to be infected with S. citri. Stubborn affected citrus trees represent an important reservoir of S. citri, and Circulifer tenellus is an active leafhopper vector of S. citri. Hence, it is not surprising that in California MLO-infected fruit trees could also become infected with S. citri but it would not mean that S. citri is the causal agent of the disease. Criteria are discussed that are helpful in distinguishing between MLO infections and S. citri infections.

  4. [Dorsal gliding and functional spaces of the metacarpophalangeal transition].

    PubMed

    Bade, H; Schubert, M; Koebke, J

    1994-09-01

    Although the relevance of capillary and gliding spaces of the back of the hand and the finger located dorsal to the extensor aponeurosis in the metacarpo-phalangeal region between the layers of the subdermal connective tissue is often emphasized clinically in inflammatory and acute traumatic occurrences, hardly any information has been published concerning the morphology of these spaces. By means of plastic-injection techniques, varying configurations of capillary spaces in the distal region of the dorsum manus of cadavers were found. The deep connective tissue spaces located dorsal to the extensor aponeurosis were shown to have proximal connections to the dorsal tendon sheaths of the carpus, whereas superficial gliding spaces tended to vary in their expanse depending on the subcutaneous and epifascial septa. The deep as well as the superficial capillary gliding spaces are adapted as mobilizing and limiting structures for the movements of the metacarpo-phalangeal joints and the various mechanical stresses of the skin of the back of the hand. A high degree of exactness in the reconstruction of the marginal elements of such functional spaces appears to be of special importance with regard to a total restoration of the functional capability of the metacarpo-phalangeal joint region.

  5. Intestinal mycoplasma in Crohn's disease.

    PubMed

    Roediger, W E W

    2004-01-01

    Intestinal diversion with reconnection in active Crohn's disease (CD) indicates that luminal contents or bacteria contribute to the formation of CD lesions. Fluorescent staining for mycoplasma in freshly resected Crohn's tissue and electron microscopy reveal intracellular organisms akin to mycoplasma. Historically, tissue culture of CD has shown mycoplasma described as contaminants. Mycoplasma are surface epithelial parasites requiring exogenous cholesterol for membrane stability and cell entry. PCR of intestinal tissue has shown Mycoplasma pneumoniae to be detectable more significantly in CD. Oral M. iowae in experimental poultry localizes to the distal small bowel and colon. Hypothetically, lipopeptides of mycoplasmal membranes are proposed to cause chronicity and stronger immune responses than by other bacteria. 'Intestinal' mycoplasmas, from a number of observations, deserve consideration as organisms mediating inflammation of acute and chronic CD.

  6. Structures of the Toxoplasma gliding motility adhesin

    PubMed Central

    Song, Gaojie; Springer, Timothy A.

    2014-01-01

    Micronemal protein 2 (MIC2) is the key adhesin that supports gliding motility and host cell invasion by Toxoplasma gondii. With a von Willebrand factor A (VWA) domain and six thrombospondin repeat domains (TSR1–6) in its ectodomain, MIC2 connects to the parasite actomyosin system through its cytoplasmic tail. MIC2-associated protein (M2AP) binds noncovalently to the MIC2 ectodomain. MIC2 and M2AP are stored in micronemes as proforms. We find that the MIC2–M2AP ectodomain complex is a highly elongated 1:1 monomer with M2AP bound to the TSR6 domain. Crystal structures of N-terminal fragments containing the VWA and TSR1 domains for proMIC2 and MIC2 reveal a closed conformation of the VWA domain and how it associates with the TSR1 domain. A long, proline-rich, disulfide-bonded pigtail loop in TSR1 overlaps the VWA domain. Mannose α-C-linked to Trp-276 in TSR1 has an unusual 1C4 chair conformation. The MIC2 VWA domain includes a mobile α5-helix and a 22-residue disordered region containing two disulfide bonds in place of an α6-helix. A hydrophobic residue in the prodomain binds to a pocket adjacent to the α7-helix that pistons in opening of the VWA domain to a putative high-affinity state. PMID:24639528

  7. Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM)

    SciTech Connect

    Sato, Chikara; Manaka, Sachie; Nakane, Daisuke; Nishiyama, Hidetoshi; Suga, Mitsuo; Nishizaka, Takayuki; Miyata, Makoto; Maruyama, Yuusuke

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. Black-Right-Pointing-Pointer Characteristic protein localizations were visualized using immuno-labeling. Black-Right-Pointing-Pointer M. mobile attached to sialic acid on the SiN film surface within minutes. Black-Right-Pointing-Pointer Cells were observed at low concentrations. Black-Right-Pointing-Pointer ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3 {mu}m-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

  8. Gliding resistance and modifications of gliding surface of tendon: clinical perspectives.

    PubMed

    Amadio, Peter C

    2013-05-01

    The smooth gliding of the normal human digital flexor is maintained by synovial fluid lubrication and lubricants bound to the tendon surface. This system can be disrupted by degenerative conditions such as trigger finger, or by trauma. The resistance to tendon gliding after surgical repair of the lacerated digital flexor tendon relates to location of suture knots, exposure of suture materials, and type of surgical repair and materials. Restoration of a functioning gliding surface after injury can be helped by using low-friction, high-strength suture designs, therapy that enables gliding, and the addition of lubricants to the tendon surface.

  9. A Mesozoic gliding mammal from northeastern China.

    PubMed

    Meng, Jin; Hu, Yaoming; Wang, Yuanqing; Wang, Xiaolin; Li, Chuankui

    2006-12-14

    Gliding flight has independently evolved many times in vertebrates. Direct evidence of gliding is rare in fossil records and is unknown in mammals from the Mesozoic era. Here we report a new Mesozoic mammal from Inner Mongolia, China, that represents a previously unknown group characterized by a highly specialized insectivorous dentition and a sizable patagium (flying membrane) for gliding flight. The patagium is covered with dense hair and supported by an elongated tail and limbs; the latter also bear many features adapted for arboreal life. This discovery extends the earliest record of gliding flight for mammals to at least 70 million years earlier in geological history, and demonstrates that early mammals were diverse in their locomotor strategies and lifestyles; they had experimented with an aerial habit at about the same time as, if not earlier than, when birds endeavoured to exploit the sky.

  10. Comparison of Hypoalgesic Effects of Neural Stretching vs Neural Gliding: A Randomized Controlled Trial.

    PubMed

    Beltran-Alacreu, Hector; Jiménez-Sanz, Laura; Fernández Carnero, Josue; La Touche, Roy

    2015-01-01

    The purpose of this study was to evaluate the immediate mechanical hypoalgesic effect of neural mobilization in asymptomatic subjects. We also compared neural gliding vs neural stretching to see which produced greater hypoalgesic effects in asymptomatic subjects. Forty-five asymptomatic subjects (20 men and 25 women; mean ± SD age, 20.8 ± 2.83 years) were randomly allocated into 3 groups: the neural glide group, the neural stretch group, and the placebo group. Each subject received 1 treatment session. Outcome measures included bilateral pressure pain threshold measured at the trigeminal, cervical, and tibialis anterior points, assessed pre-treatment and immediately post-treatment by a blinded assessor. Three-way repeated-measures analysis of variance was used to evaluate changes in pressure pain threshold, with group (experimental or control) as the between-subjects variable and time (pre-, post-treatment) or side (dominant, nondominant) as the within-subjects variable. Group differences were identified between neural mobilization groups and the placebo group. Changes occurred in all of the pressure pain threshold measures for neural gliding, and in all but the trigeminal point for neural stretch. No changes in the pressure pain threshold measures occurred in the placebo group. This research provides new experimental evidence that neural mobilization produces an immediate widespread hypoalgesic effect vs placebo but neural gliding produces hypoalgesic effects in more body sites than neural stretching. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  11. A rotary motor drives Flavobacterium gliding.

    PubMed

    Shrivastava, Abhishek; Lele, Pushkar P; Berg, Howard C

    2015-02-02

    Cells of Flavobacterium johnsoniae, a rod-shaped bacterium devoid of pili or flagella, glide over glass at speeds of 2-4 μm/s [1]. Gliding is powered by a protonmotive force [2], but the machinery required for this motion is not known. Usually, cells move along straight paths, but sometimes they exhibit a reciprocal motion, attach near one pole and flip end over end, or rotate. This behavior is similar to that of a Cytophaga species described earlier [3]. Development of genetic tools for F. johnsoniae led to discovery of proteins involved in gliding [4]. These include the surface adhesin SprB that forms filaments about 160 nm long by 6 nm in diameter, which, when labeled with a fluorescent antibody [2] or a latex bead [5], are seen to move longitudinally down the length of a cell, occasionally shifting positions to the right or the left. Evidently, interaction of these filaments with a surface produces gliding. To learn more about the gliding motor, we sheared cells to reduce the number and size of SprB filaments and tethered cells to glass by adding anti-SprB antibody. Cells spun about fixed points, mostly counterclockwise, rotating at speeds of 1 Hz or more. The torques required to sustain such speeds were large, comparable to those generated by the flagellar rotary motor. However, we found that a gliding motor runs at constant speed rather than at constant torque. Now, there are three rotary motors powered by protonmotive force: the bacterial flagellar motor, the Fo ATP synthase, and the gliding motor.

  12. A rotary motor drives Flavobacterium gliding

    PubMed Central

    Shrivastava, Abhishek; Lele, Pushkar P.; Berg, Howard C.

    2015-01-01

    Summary Cells of Flavobacterium johnsoniae, a rod-shaped bacterium devoid of pili or flagella, glide over glass at speeds of 2–4 μm/s [1]. Gliding is powered by a protonmotive force [2], but the machinery required for this motion is not known. Usually, cells move along straight paths, but sometimes they exhibit a reciprocal motion, attach near one pole and flip end-over-end, or rotate. This behavior is similar to that of a Cytophaga species described earlier [3]. Development of genetic tools for F. johnsoniae led to discovery of proteins involved in gliding [4]. These include the surface adhesin SprB that forms filaments about 160 nm long by 6 nm in diameter, which, when labeled with a fluorescent antibody [2] or a latex bead [5], are seen to move longitudinally down the length of a cell, occasionally shifting positions to the right or the left. Evidently, interaction of these filaments with a surface produces gliding. To learn more about the gliding motor, we sheared cells to reduce the number and size of SprB filaments and tethered cells to glass by adding anti-SprB antibody. Cells spun about fixed points, mostly counterclockwise, rotating at speeds of 1 Hz or more. The torques required to sustain such speeds were large, comparable to those generated by the flagellar rotary motor. However, we found that a gliding motor runs at constant speed rather than constant torque. Now there are three rotary motors powered by protonmotive force: the bacterial flagellar motor, the Fo ATP synthase, and the gliding motor. PMID:25619763

  13. Animal model of Mycoplasma fermentans respiratory infection

    PubMed Central

    2013-01-01

    Background Mycoplasma fermentans has been associated with respiratory, genitourinary tract infections and rheumatoid diseases but its role as pathogen is controversial. The purpose of this study was to probe that Mycoplasma fermentans is able to produce respiratory tract infection and migrate to several organs on an experimental infection model in hamsters. One hundred and twenty six hamsters were divided in six groups (A-F) of 21 hamsters each. Animals of groups A, B, C were intratracheally injected with one of the mycoplasma strains: Mycoplasma fermentans P 140 (wild strain), Mycoplasma fermentans PG 18 (type strain) or Mycoplasma pneumoniae Eaton strain. Groups D, E, F were the negative, media, and sham controls. Fragments of trachea, lungs, kidney, heart, brain and spleen were cultured and used for the histopathological study. U frequency test was used to compare recovery of mycoplasmas from organs. Results Mycoplasmas were detected by culture and PCR. The three mycoplasma strains induced an interstitial pneumonia; they also migrated to several organs and persisted there for at least 50 days. Mycoplasma fermentans P 140 induced a more severe damage in lungs than Mycoplasma fermentans PG 18. Mycoplasma pneumoniae produced severe damage in lungs and renal damage. Conclusions Mycoplasma fermentans induced a respiratory tract infection and persisted in different organs for several weeks in hamsters. This finding may help to explain the ability of Mycoplasma fermentans to induce pneumonia and chronic infectious diseases in humans. PMID:23298636

  14. [The comparison of tests for qualitative evaluation of Ureaplasma parvum, Mycoplasma hominis: "Mycoplasma duo", "Ureaplasma microtest", "Mycoplasma microtest" and "AmpliSens-Florocenosis-mycoplasma-FL"].

    PubMed

    Rumiantseva, T A; Varlamova, A V; Gushchin, A E; Bezrukov, V M

    2014-08-01

    The genital mycoplasma is an opportunistic bacteria and its detection is to be implemented in qualitative format. The study was organized to compare reagents kits "Mycoplasma Duo", "Ureaplasma Microtest", "Mycoplasma microtest" and "AmpliSens-Florocenosis-Mycoplasma-FL". The study resulted in high indicators of diagnostic sensitivity and diagnostic specificity for all kits. At that, the lowest indicators were registered under application of "Mycoplasma Duo" kit. The study reveled correlation of qualitative values detected by using cultural analysis and polymerase chain reaction. The reproducibility of qualitative values of cultural method occurred significantly lower in comparison with "AmpliSens-Florocenosis-Mycoplasma-FL " kit.

  15. Polymer confinement and bacterial gliding motility

    NASA Astrophysics Data System (ADS)

    Jeon, J.; Dobrynin, A. V.

    2005-07-01

    Cyanobacteria and myxobacteria use slime secretion for gliding motility over surfaces. The slime is produced by the nozzle-like pores located on the bacteria surface. To understand the mechanism of gliding motion and its relation to slime polymerization, we have performed molecular dynamics simulations of a molecular nozzle with growing inside polymer chains. These simulations show that the compression of polymer chains inside the nozzle is a driving force for propulsion. There is a linear relationship between the average nozzle velocity and the chain polymerization rate with a proportionality coefficient dependent on the geometric characteristics of the nozzle such as its length and friction coefficient. This minimal model of the molecular engine was used to explain the gliding motion of bacteria over surfaces.

  16. Systematic Structural Analyses of Attachment Organelle in Mycoplasma pneumoniae.

    PubMed

    Nakane, Daisuke; Kenri, Tsuyoshi; Matsuo, Lisa; Miyata, Makoto

    2015-12-01

    Mycoplasma pneumoniae, a human pathogenic bacterium, glides on host cell surfaces by a unique and unknown mechanism. It forms an attachment organelle at a cell pole as a membrane protrusion composed of surface and internal structures, with a highly organized architecture. In the present study, we succeeded in isolating the internal structure of the organelle by sucrose-gradient centrifugation. The negative-staining electron microscopy clarified the details and dimensions of the internal structure, which is composed of terminal button, paired plates, and bowl complex from the end of cell front. Peptide mass fingerprinting of the structure suggested 25 novel components for the organelle, and 3 of them were suggested for their involvement in the structure through their subcellular localization determined by enhanced yellow fluorescent protein (EYFP) tagging. Thirteen component proteins including the previously reported ones were mapped on the organelle systematically for the first time, in nanometer order by EYFP tagging and immunoelectron microscopy. Two, three, and six specific proteins localized specifically to the terminal button, the paired plates, and the bowl, respectively and interestingly, HMW2 molecules were aligned parallel to form the plate. The integration of these results gave the whole image of the organelle and allowed us to discuss possible gliding mechanisms.

  17. Systematic Structural Analyses of Attachment Organelle in Mycoplasma pneumoniae

    PubMed Central

    Matsuo, Lisa; Miyata, Makoto

    2015-01-01

    Mycoplasma pneumoniae, a human pathogenic bacterium, glides on host cell surfaces by a unique and unknown mechanism. It forms an attachment organelle at a cell pole as a membrane protrusion composed of surface and internal structures, with a highly organized architecture. In the present study, we succeeded in isolating the internal structure of the organelle by sucrose-gradient centrifugation. The negative-staining electron microscopy clarified the details and dimensions of the internal structure, which is composed of terminal button, paired plates, and bowl complex from the end of cell front. Peptide mass fingerprinting of the structure suggested 25 novel components for the organelle, and 3 of them were suggested for their involvement in the structure through their subcellular localization determined by enhanced yellow fluorescent protein (EYFP) tagging. Thirteen component proteins including the previously reported ones were mapped on the organelle systematically for the first time, in nanometer order by EYFP tagging and immunoelectron microscopy. Two, three, and six specific proteins localized specifically to the terminal button, the paired plates, and the bowl, respectively and interestingly, HMW2 molecules were aligned parallel to form the plate. The integration of these results gave the whole image of the organelle and allowed us to discuss possible gliding mechanisms. PMID:26633540

  18. 14 CFR 171.267 - Glide path automatic monitor system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... to more than 0.075θ. (2) For glide paths in which the basic functions are provided by the use of a... element being monitored. (b) At glide path facilities where the selected nominal angular displacement...

  19. 14 CFR 171.267 - Glide path automatic monitor system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... to more than 0.075θ. (2) For glide paths in which the basic functions are provided by the use of a... element being monitored. (b) At glide path facilities where the selected nominal angular displacement...

  20. 14 CFR 171.267 - Glide path automatic monitor system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... to more than 0.075θ. (2) For glide paths in which the basic functions are provided by the use of a... element being monitored. (b) At glide path facilities where the selected nominal angular displacement...

  1. 14 CFR 171.267 - Glide path automatic monitor system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... to more than 0.075θ. (2) For glide paths in which the basic functions are provided by the use of a... element being monitored. (b) At glide path facilities where the selected nominal angular displacement...

  2. Mycoplasma polysaccharide protects against complement

    PubMed Central

    Bolland, Jeffrey R.; Simmons, Warren L.; Daubenspeck, James M.

    2012-01-01

    Although they lack a cell wall, mycoplasmas do possess a glycocalyx. The interactions between the glycocalyx, mycoplasmal surface proteins and host complement were explored using the murine pathogen Mycoplasma pulmonis as a model. It was previously shown that the length of the tandem repeat region of the surface lipoprotein Vsa is associated with susceptibility to complement-mediated killing. Cells producing a long Vsa containing about 40 repeats are resistant to complement, whereas strains that produce a short Vsa of five or fewer repeats are susceptible. We show here that the length of the Vsa protein modulates the affinity of the M. pulmonis EPS-I polysaccharide for the mycoplasma cell surface, with more EPS-I being associated with mycoplasmas producing a short Vsa protein. An examination of mutants that lack EPS-I revealed that planktonic mycoplasmas were highly susceptible to complement killing even when the Vsa protein was long, demonstrating that both EPS-I and Vsa length contribute to resistance. In contrast, the mycoplasmas were resistant to complement even in the absence of EPS-I when the cells were encased in a biofilm. PMID:22504437

  3. A practitioner's tool for assessing glide crack activity

    USGS Publications Warehouse

    Hendrikx, Jordy; Peitzsch, Erich H.; Fagre, Daniel B.

    2010-01-01

    Glide cracks can result in full-depth glide avalanche release. Avalanches from glide cracks are notoriously difficult to forecast, but are a reoccurring problem in a number of different avalanche forecasting programs across a range of snow climates. Despite this, there is no consensus for how to best manage, mitigate, or even observe glide cracks and the potential resultant avalanche activity. It is thought that an increase in the rate of snow gliding occurs prior to full-depth avalanche activity, so frequent measuring of glide crack movement provides an index of instability. Therefore, a comprehensive avalanche program with glide crack avalanche activity, should at the least, undertake some form of direct monitoring of glide crack movement. In this paper we present a simple, cheap and repeatable method to track glide crack activity using a series of stakes, reflectors and a laser rangefinder (LaserTech TruPulse360B) linked to a GPS (Trimble Geo XH). We tested the methodology in April 2010, on a glide crack above the Going to the Sun Road in Glacier National Park, Montana, USA. This study suggests a new method to better track the development and movement of glide cracks. It is hoped that by introducing a workable method to easily record glide crack movement, avalanche forecasters will improve their understanding of when, or if, avalanche activity will ensue. Our initial results suggest that these new observations, when combined with local micrometeorological data will result in improved process understanding and forecasting of these phenomena.

  4. Aerodynamic Characteristics and Glide-Back Performance of Langley Glide-Back Booster

    NASA Technical Reports Server (NTRS)

    Pamadi, Bandu N.; Covell, Peter F.; Tartabini, Paul V.; Murphy, Kelly J.

    2004-01-01

    NASA-Langley Research Center is conducting system level studies on an-house concept of a small launch vehicle to address NASA's needs for rapid deployment of small payloads to Low Earth Orbit. The vehicle concept is a three-stage system with a reusable first stage and expendable upper stages. The reusable first stage booster, which glides back to launch site after staging around Mach 3 is named the Langley Glide-Back Booster (LGBB). This paper discusses the aerodynamic characteristics of the LGBB from subsonic to supersonic speeds, development of the aerodynamic database and application of this database to evaluate the glide back performance of the LGBB. The aerodynamic database was assembled using a combination of wind tunnel test data and engineering level analysis. The glide back performance of the LGBB was evaluated using a trajectory optimization code and subject to constraints on angle of attack, dynamic pressure and normal acceleration.

  5. Investigation of gliding flight by flying fish

    NASA Astrophysics Data System (ADS)

    Park, Hyungmin; Jeon, Woo-Pyung; Choi, Haecheon

    2006-11-01

    The most successful flight capability of fish is observed in the flying fish. Furthermore, despite the difference between two medium (air and water), the flying fish is well evolved to have an excellent gliding performance as well as fast swimming capability. In this study, flying fish's morphological adaptation to gliding flight is experimentally investigated using dry-mounted darkedged-wing flying fish, Cypselurus Hiraii. Specifically, we examine the effects of the pectoral and pelvic fins on the aerodynamic performance considering (i) both pectoral and pelvic fins, (ii) pectoral fins only, and (iii) body only with both fins folded. Varying the attack angle, we measure the lift, drag and pitching moment at the free-stream velocity of 12m/s for each case. Case (i) has higher lift-to-drag ratio (i.e. longer gliding distance) and more enhanced longitudinal static stability than case (ii). However, the lift coefficient is smaller for case (i) than for case (ii), indicating that the pelvic fins are not so beneficial for wing loading. The gliding performance of flying fish is compared with those of other fliers and is found to be similar to those of insects such as the butterfly and fruitfly.

  6. Global dynamics of non-equilibrium gliding in animals.

    PubMed

    Yeaton, Isaac J; Socha, John J; Ross, Shane D

    2017-03-17

    Gliding flight-moving horizontally downward through the air without power-has evolved in a broad diversity of taxa and serves numerous ecologically relevant functions such as predator escape, expanding foraging locations, and finding mates, and has been suggested as an evolutionary pathway to powered flight. Historically, gliding has been conceptualized using the idealized conditions of equilibrium, in which the net aerodynamic force on the glider balances its weight. While this assumption is appealing for its simplicity, recent studies of glide trajectories have shown that equilibrium gliding is not the norm for most species. Furthermore, equilibrium theory neglects the aerodynamic differences between species, as well as how a glider can modify its glide path using control. To investigate non-equilibrium glide behavior, we developed a reduced-order model of gliding that accounts for self-similarity in the equations of motion, such that the lift and drag characteristics alone determine the glide trajectory. From analysis of velocity polar diagrams of horizontal and vertical velocity from several gliding species, we find that pitch angle, the angle between the horizontal and chord line, is a control parameter that can be exploited to modulate glide angle and glide speed. Varying pitch results in changing locations of equilibrium glide configurations in the velocity polar diagram that govern passive glide dynamics. Such analyses provide a new mechanism of interspecies comparison and tools to understand experimentally-measured kinematics data and theory. In addition, this analysis suggests that the lift and drag characteristics of aerial and aquatic autonomous gliders can be engineered to passively alter glide trajectories with minimal control effort.

  7. Mycoplasmas in diseases of humans.

    PubMed Central

    Embree, J E; Embil, J A

    1980-01-01

    The roles of Mycoplasma pneumoniae, M. hominis and Ureaplasma urealyticum in diseases of humans are currently under investigation. M. pneumoniae, which causes primary atypical pneumonia, is a well established pathogen of the respiratory tract. Complications of infection by this organism are also being recognized; they include disorders of the hematopoietic, cardiovascular, central nervous, musculoskeletal, cutaneous and gastrointestinal systems. The roles of the genital mycoplasmas M. hominis and U. urealyticum are controversial but may include infections of the genitourinary tract and in pregnancy as well as diseases of the newborn, such as neonatal pneumonia and meningitis. In this review atypical pneumonia due to M. pneumoniae is described and the role of mycoplasmas in other diseases is discussed. Images FIG. 1A FIG. 1B FIG. 2 PMID:6790148

  8. GLIDES – Efficient Energy Storage from ORNL

    SciTech Connect

    Momen, Ayyoub M.; Abu-Heiba, Ahmad; Odukomaiya, Wale; Akinina, Alla

    2016-03-01

    The research shown in this video features the GLIDES (Ground-Level Integrated Diverse Energy Storage) project, which has been under development at Oak Ridge National Laboratory (ORNL) since 2013. GLIDES can store energy via combined inputs of electricity and heat, and deliver dispatchable electricity. Supported by ORNL’s Laboratory Director’s Research and Development (LDRD) fund, this energy storage system is low-cost, and hybridizes compressed air and pumped-hydro approaches to allow for storage of intermittent renewable energy at high efficiency. A U.S. patent application for this novel energy storage concept has been submitted, and research findings suggest it has the potential to be a flexible, low-cost, scalable, high-efficiency option for energy storage, especially useful in residential and commercial buildings.

  9. On complex, curved trajectories in microtubule gliding

    NASA Astrophysics Data System (ADS)

    Gosselin, Pierre; Mohrbach, Hervé; Kulić, Igor M.; Ziebert, Falko

    2016-04-01

    We study the dynamics of microtubules in gliding assays. These biofilaments are typically considered as purely semiflexible, hence their trajectories under the action of motors covering the substrate have been regarded so far as straight, modulo fluctuations. However, this is not always the case experimentally, where microtubules are known to move on large scale circles or spirals, or even display quite regular wavy trajectories and more complex dynamics. Incorporating recent experimental evidence for a (small) preferred curvature as well as the microtubules' well established lattice twist into a dynamic model for microtubule gliding, we could reproduce both types of trajectories. Interestingly, as a function of the microtubules' length we found length intervals of stable rings alternating with regions where wavy and more complex dynamics prevails. Finally, both types of dynamics (rings and waves) can be rationalized by considering simple limits of the full model.

  10. Optimal Paths in Gliding Flight

    NASA Astrophysics Data System (ADS)

    Wolek, Artur

    Underwater gliders are robust and long endurance ocean sampling platforms that are increasingly being deployed in coastal regions. This new environment is characterized by shallow waters and significant currents that can challenge the mobility of these efficient (but traditionally slow moving) vehicles. This dissertation aims to improve the performance of shallow water underwater gliders through path planning. The path planning problem is formulated for a dynamic particle (or "kinematic car") model. The objective is to identify the path which satisfies specified boundary conditions and minimizes a particular cost. Several cost functions are considered. The problem is addressed using optimal control theory. The length scales of interest for path planning are within a few turn radii. First, an approach is developed for planning minimum-time paths, for a fixed speed glider, that are sub-optimal but are guaranteed to be feasible in the presence of unknown time-varying currents. Next the minimum-time problem for a glider with speed controls, that may vary between the stall speed and the maximum speed, is solved. Last, optimal paths that minimize change in depth (equivalently, maximize range) are investigated. Recognizing that path planning alone cannot overcome all of the challenges associated with significant currents and shallow waters, the design of a novel underwater glider with improved capabilities is explored. A glider with a pneumatic buoyancy engine (allowing large, rapid buoyancy changes) and a cylindrical moving mass mechanism (generating large pitch and roll moments) is designed, manufactured, and tested to demonstrate potential improvements in speed and maneuverability.

  11. Pathobiology of Mycoplasma suis.

    PubMed

    Hoelzle, Ludwig E; Zeder, Michael; Felder, Kathrin M; Hoelzle, Katharina

    2014-10-01

    Mycoplasma suis is an uncultivable bacterium lacking a cell wall that attaches to and may invade the red blood cells of pigs. M. suis infections occur worldwide and cause the pig industry serious economic losses due to the disease known as infectious anaemia of pigs or, historically, porcine eperythrozoonosis. Infectious anaemia of pigs is characterised predominantly by acute haemolytic or chronic anaemia, along with non-specific manifestations, such as growth retardation in feeder pigs and poor reproductive performance in sows. The fastidious nature of M. suis, as well as the lack of an in vitro cultivation system, has hampered the understanding of the biology and pathogenicity of this organism. Pathogenetic mechanisms of M. suis include direct destruction of red blood cells by adhesion, invasion, nutrient scavenging, immune-mediated lysis and eryptosis, as well as endothelial targeting. Recently published genome sequences, in combination with proteome analyses, have generated new insights into the pathogenicity of M. suis. The present review combines these data with the knowledge provided by experimental M. suis infections.

  12. Mycoplasma infections in small ruminants.

    PubMed

    Ruffin, D C

    2001-07-01

    Mycoplasmas have complex mechanisms of antigenic variation that allow them to evade the immune system. These organisms cause a variety of clinical syndromes that can have a significant economic effect on small ruminant production. The syndromes range from acute septicemia and death to chronic infection resulting in decreased production. Recent research findings have shed light on the means by which these organisms evade the host immune response and cause or contribute to the development of disease in the host. This article provides a review of the pathogenesis, clinical signs, and treatment options for common disease syndromes involving Mycoplasma spp. in small ruminants.

  13. Polymer confinement and bacterial gliding motility

    NASA Astrophysics Data System (ADS)

    Jeon, Junhwan; Dobrynin, Andrey

    2006-03-01

    Cyanobacteria and myxobacteria use slime secretion for gliding motility over surfaces. In cyanobacteria the slime is extruded from the nozzle-like pores of 14-16 nm outer diameter and approximately 7nm inner diameter located near the septa that separate the cells of a filament. The pores are inclined at an angle of 30-40 degrees relative to the cell axes, and are oppositely directed on both sides of the septum. Such pore orientation provides directionality for the slime secretion as well as cell motion. To understand the mechanism of gliding motion and its relation to slime polymerization, we have performed molecular dynamics simulations of a molecular nozzle with growing inside polymer chains. These simulations show that the compression of polymer chains inside the nozzle is a driving force for its propulsion. There is a linear relationship between the average nozzle velocity and the chain polymerization rate with a proportionality coefficient dependent on the geometric characteristics of the nozzle such as its length and friction coefficient. This minimal model of the molecular engine was used to explain the gliding motion of cyanobacteria and myxobacteria over surfaces.

  14. Optical diagnostics of a gliding arc.

    PubMed

    Sun, Z W; Zhu, J J; Li, Z S; Aldén, M; Leipold, F; Salewski, M; Kusano, Y

    2013-03-11

    Dynamic processes in a gliding arc plasma generated between two diverging electrodes in ambient air driven by 31.25 kHz AC voltage were investigated using spatially and temporally resolved optical techniques. The life cycles of the gliding arc were tracked in fast movies using a high-speed camera with framing rates of tens to hundreds of kHz, showing details of ignition, motion, pulsation, short-cutting, and extinction of the plasma column. The ignition of a new discharge occurs before the extinction of the previous discharge. The developed, moving plasma column often short-cuts its current path triggered by Townsend breakdown between the two legs of the gliding arc. The emission from the plasma column is shown to pulsate at a frequency of 62.5 kHz, i.e., twice the frequency of the AC power supply. Optical emission spectra of the plasma radiation show the presence of excited N2, NO and OH radicals generated in the plasma and the dependence of their relative intensities on both the distance relative to the electrodes and the phase of the driving AC power. Planar laser-induced fluorescence of the ground-state OH radicals shows high intensity outside the plasma column rather than in the center suggesting that ground-state OH is not formed in the plasma column but in its vicinity.

  15. Non-occurrence of Mycoplasma genitalium in clinical specimens.

    PubMed

    Samra, Z; Borin, M; Bukowsky, Y; Lipshitz, Y; Sompolinsky, D

    1988-02-01

    Five hundred and thirteen clinical specimens, mainly from patients with urogenital inflammations, were examined for Ureaplasma urealyticum and mycoplasmas, including cultures for Mycoplasma genitalium. The study yielded 95 isolates of Ureaplasma urealyticum, 37 isolates of Mycoplasma hominis and two isolates of Mycoplasma fermentans, but no growth of Mycoplasma genitalium was obtained. It was concluded that Mycoplasma genitalium is a relatively rare inhabitant of the human urogenital tract in Israel.

  16. Draft Genome Sequence of "Candidatus Mycoplasma haemobos," a Hemotropic Mycoplasma Identified in Cattle in Mexico.

    PubMed

    Martínez-Ocampo, Fernando; Rodríguez-Camarillo, Sergio D; Amaro-Estrada, Itzel; Quiroz-Castañeda, Rosa Estela

    2016-07-07

    We present here the draft genome sequence of the first "Candidatus Mycoplasma haemobos" strain found in cattle in Mexico. This hemotropic mycoplasma causes acute and chronic disease in animals. This genome is a starting point for studying the role of this mycoplasma in coinfections and synergistic mechanisms associated with the disease.

  17. Assessing the importance of terrain parameters on glide avalanche release

    USGS Publications Warehouse

    Peitzsch, Erich H.; Hendrikx, Jordy; Fagre, Daniel B.

    2014-01-01

    Glide snow avalanches are dangerous and difficult to predict. Despite recent research there is still a lack of understanding regarding the controls of glide avalanche release. Glide avalanches often occur in similar terrain or the same locations annually and observations suggest that topography may be critical. Thus, to gain an understanding of the terrain component of these types of avalanches we examined terrain parameters associated with glide avalanche release as well as areas of consistent glide crack formation but no subsequent avalanches. Glide avalanche occurrences visible from the Going-to-the-Sun Road corridor in Glacier National Park, Montana from 2003-2013 were investigated using an avalanche database derived of daily observations each year from April 1 to June 15. This yielded 192 glide avalanches in 53 distinct avalanche paths. Each avalanche occurrence was digitized in a GIS using satellite, oblique, and aerial imagery as reference. Topographical parameters such as area, slope, aspect, elevation and elevation were then derived for the entire dataset utilizing GIS tools and a 10m DEM. Land surface substrate and surface geology were derived from National Park Service Inventory and Monitoring maps and U.S. Geological Survey surface geology maps, respectively. Surface roughness and glide factor were calculated using a four level classification index. . Then, each avalanche occurrence was aggregated to general avalanche release zones and the frequencies were compared. For this study, glide avalanches released in elevations ranging from 1300 to 2700 m with a mean aspect of 98 degrees (east) and a mean slope angle of 38 degrees. The mean profile curvature for all glide avalanches was 0.15 and a plan curvature of -0.01, suggesting a fairly linear surface (i.e. neither convex nor concave). The glide avalanches occurred in mostly bedrock made up of dolomite and limestone slabs and talus deposits with very few occurring in alpine meadows. However, not all glide

  18. Activity of moxifloxacin against the urogenital mycoplasmas Ureaplasma spp., Mycoplasma hominis and Mycoplasma genitalium and Chlamydia trachomatis.

    PubMed

    Bébéar, C M; de Barbeyrac, B; Pereyre, S; Renaudin, H; Clerc, M; Bébéar, C

    2008-08-01

    The activity of moxifloxacin was compared with that of other antimicrobial agents against 54 strains of Ureaplasma spp., 54 strains of Mycoplasma hominis, 14 strains of Mycoplasma genitalium, and 44 strains of Chlamydia trachomatis. Moxifloxacin inhibited 90% of all isolates at a concentration mycoplasmas. Moxifloxacin killed the 30 mycoplasma isolates tested at a concentration

  19. Prevention and Detection of Mycoplasma Contamination in Cell Culture

    PubMed Central

    Nikfarjam, Laleh; Farzaneh, Parvaneh

    2012-01-01

    One of the main problems in cell culture is mycoplasma infection. It can extensively affect cell physiology and metabolism. As the applications of cell culture increase in research, industrial production and cell therapy, more concerns about mycoplasma contamination and detection will arise. This review will provide valuable information about: 1. the ways in which cells are contaminated and the frequency and source of mycoplasma species in cell culture; 2. the ways to prevent mycoplasma contamination in cell culture; 3. the importance of mycoplasma tests in cell culture; 4. different methods to identify mycoplasma contamination; 5. the consequences of mycoplasma contamination in cell culture and 6. available methods to eliminate mycoplasma contamination. Awareness about the sources of mycoplasma and pursuing aseptic techniques in cell culture along with reliable detection methods of mycoplasma contamination can provide an appropriate situation to prevent mycoplasma contamination in cell culture. PMID:23508237

  20. Aerodynamics of gliding flight in common swifts.

    PubMed

    Henningsson, P; Hedenström, A

    2011-02-01

    Gliding flight performance and wake topology of a common swift (Apus apus L.) were examined in a wind tunnel at speeds between 7 and 11 m s(-1). The tunnel was tilted to simulate descending flight at different sink speeds. The swift varied its wingspan, wing area and tail span over the speed range. Wingspan decreased linearly with speed, whereas tail span decreased in a nonlinear manner. For each airspeed, the minimum glide angle was found. The corresponding sink speeds showed a curvilinear relationship with airspeed, with a minimum sink speed at 8.1 m s(-1) and a speed of best glide at 9.4 m s(-1). Lift-to-drag ratio was calculated for each airspeed and tilt angle combinations and the maximum for each speed showed a curvilinear relationship with airspeed, with a maximum of 12.5 at an airspeed of 9.5 m s(-1). Wake was sampled in the transverse plane using stereo digital particle image velocimetry (DPIV). The main structures of the wake were a pair of trailing wingtip vortices and a pair of trailing tail vortices. Circulation of these was measured and a model was constructed that showed good weight support. Parasite drag was estimated from the wake defect measured in the wake behind the body. Parasite drag coefficient ranged from 0.30 to 0.22 over the range of airspeeds. Induced drag was calculated and used to estimate profile drag coefficient, which was found to be in the same range as that previously measured on a Harris' hawk.

  1. ILLUSTRATED GLOSSARY OF FRACTOGRAPHIC TERMS; SECTION 2: GLIDE PLANE DECOHESION, SERPENTINE GLIDE, RIPPLES, STRETCHING, MICROVOID COALESCENCE.

    DTIC Science & Technology

    discussed where they are known. Glide plane decohesion, as it has been used in the literature, is shown to be misleading, and a more descriptive term ...8217stretching’, is used in its place. The use of ’ductile cleavage’ to describe the same process should be discontinued. Several terms have evolved to

  2. Mycoplasma infection of ducks and geese.

    PubMed

    Stipkovits, L; Szathmary, S

    2012-11-01

    Production of ducks and geese in certain parts of the world is very important. Mycoplasma diseases cause significant losses to the duck and goose industry. This review summarizes the epidemiological, clinical, and pathomorphological characteristics of mycoplasma diseases of ducks and geese and the involvement of the various mycoplasma species in their pathogenesis. The role of mycoplasma infections in the development of clinical signs, pathological lesions, and mortality of challenged birds is demonstrated in challenge experiments. Transmission of mycoplasma in the ovary and eggs resulting in the reduction of egg production and an increase of embryo mortality has been shown in challenge experiments as well as in field studies. The susceptibility of many mycoplasma isolates of the most important mycoplasma species of duck and goose origin were tested and showed relatively high average minimum inhibitory concentrations of lincomycin, tilosin, oxytetracycline, chlortetracycline, and enrofloxacin but not for tiamulin. The successful treatment of mycoplasma infections with antibiotics in ducks and geese should be selected based on the minimum inhibitory concentration values against the mycoplasmas isolated from the flock.

  3. Relationships between glide efficiency and swimmers' size and shape characteristics.

    PubMed

    Naemi, Roozbeh; Psycharakis, Stelios G; McCabe, Carla; Connaboy, Chris; Sanders, Ross H

    2012-08-01

    Glide efficiency, the ability of a body to minimize deceleration over the glide, can change with variations in the body's size and shape. The purpose of this study was to investigate the relationships between glide efficiency and the size and shape characteristics of swimmers. Eight male and eight female swimmers performed a series of horizontal glides at a depth of 70 cm below the surface. Glide efficiency parameters were calculated for velocities ranging from 1.4 to 1.6 m/s for female swimmers (and at the Reynolds number of 3.5 million) and from 1.6 to 1.8 m/s for male swimmers (and at the Reynolds number of 4.5 million). Several morphological indices were calculated to account for the shape characteristics, with the use of a photogrammetric method. Relationships between the variables of interest were explored with correlations, while repeated-measures ANOVA was used to assess within-group differences between different velocities for each gender group. Glide efficiency of swimmers increased when velocity decreased. Some morphological indices and postural angles showed a significant correlation with glide efficiency. The glide coefficient was significantly correlated to the chest to waist taper index for both gender groups. For the male group, the glide coefficient correlated significantly to the fineness ratio of upper body, the chest to hip cross-section. For the female group the glide coefficient had a significant correlation with the waist to hip taper index. The findings suggested that gliding efficiency was more dependent on shape characteristics and appropriate postural angles rather than being dependent on size characteristics.

  4. Gliding motility and polarized slime secretion.

    PubMed

    Yu, Rosa; Kaiser, Dale

    2007-01-01

    Myxococcus leaves a trail of slime on agar as it moves. A filament of slime can be seen attached to the end of a cell, but it is seen only at one end at any particular moment. To identify genes essential for A motility, transposon insertion mutations with defective A motility were studied. Fifteen of the 33 mutants had totally lost A motility. All these mutant cells had filaments of slime emerging from both ends, indicating that bipolar secretion prevents A motility. The remaining 18 A motility mutants, also produced by gene knockout, secreted slime only from one pole, but they swarmed at a lower rate than A(+) and are called 'partial' gliding mutants, or pgl. For each pgl mutant, the reduction in swarm expansion rate was directly proportional to the reduction in the coefficient of elasticotaxis. The pgl mutants have a normal reversal frequency and normal gliding speed when they move. But their probability of movement per unit time is lower than pgl(+) cells. Many of the pgl mutants are produced by transposon insertions in glycosyltransferase genes. It is proposed that these glycosyltransferases carry out the synthesis of a repeat unit polysaccharide that constitutes the slime.

  5. How swifts control their glide performance with morphing wings.

    PubMed

    Lentink, D; Müller, U K; Stamhuis, E J; de Kat, R; van Gestel, W; Veldhuis, L L M; Henningsson, P; Hedenström, A; Videler, J J; van Leeuwen, J L

    2007-04-26

    Gliding birds continually change the shape and size of their wings, presumably to exploit the profound effect of wing morphology on aerodynamic performance. That birds should adjust wing sweep to suit glide speed has been predicted qualitatively by analytical glide models, which extrapolated the wing's performance envelope from aerodynamic theory. Here we describe the aerodynamic and structural performance of actual swift wings, as measured in a wind tunnel, and on this basis build a semi-empirical glide model. By measuring inside and outside swifts' behavioural envelope, we show that choosing the most suitable sweep can halve sink speed or triple turning rate. Extended wings are superior for slow glides and turns; swept wings are superior for fast glides and turns. This superiority is due to better aerodynamic performance-with the exception of fast turns. Swept wings are less effective at generating lift while turning at high speeds, but can bear the extreme loads. Finally, our glide model predicts that cost-effective gliding occurs at speeds of 8-10 m s(-1), whereas agility-related figures of merit peak at 15-25 m s(-1). In fact, swifts spend the night ('roost') in flight at 8-10 m s(-1) (ref. 11), thus our model can explain this choice for a resting behaviour. Morphing not only adjusts birds' wing performance to the task at hand, but could also control the flight of future aircraft.

  6. 14 CFR 171.265 - Glide path performance requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) The modulating tones must be 90 Hz and 150 Hz within 2.5 percent. (2) The total harmonic content of... angular displacement sensitivity must correspond to a DDM of 0.0875 at an angular displacement above and below the glide path of 0.12θ. The glide path angular displacement sensitivity must be adjusted and...

  7. 14 CFR 23.71 - Glide: Single-engine airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Glide: Single-engine airplanes. 23.71... Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles... with the engine inoperative, its propeller in the minimum drag position, and landing gear and wing...

  8. 14 CFR 23.71 - Glide: Single-engine airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Glide: Single-engine airplanes. 23.71... Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles... with the engine inoperative, its propeller in the minimum drag position, and landing gear and wing...

  9. 14 CFR 23.71 - Glide: Single-engine airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Glide: Single-engine airplanes. 23.71... Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles... with the engine inoperative, its propeller in the minimum drag position, and landing gear and wing...

  10. 14 CFR 23.71 - Glide: Single-engine airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Glide: Single-engine airplanes. 23.71 Section 23.71 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical...

  11. 14 CFR 23.71 - Glide: Single-engine airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Glide: Single-engine airplanes. 23.71... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.71 Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles...

  12. Molecular Biology and Pathogenicity of Mycoplasmas

    PubMed Central

    Razin, Shmuel; Yogev, David; Naot, Yehudith

    1998-01-01

    The recent sequencing of the entire genomes of Mycoplasma genitalium and M. pneumoniae has attracted considerable attention to the molecular biology of mycoplasmas, the smallest self-replicating organisms. It appears that we are now much closer to the goal of defining, in molecular terms, the entire machinery of a self-replicating cell. Comparative genomics based on comparison of the genomic makeup of mycoplasmal genomes with those of other bacteria, has opened new ways of looking at the evolutionary history of the mycoplasmas. There is now solid genetic support for the hypothesis that mycoplasmas have evolved as a branch of gram-positive bacteria by a process of reductive evolution. During this process, the mycoplasmas lost considerable portions of their ancestors’ chromosomes but retained the genes essential for life. Thus, the mycoplasmal genomes carry a high percentage of conserved genes, greatly facilitating gene annotation. The significant genome compaction that occurred in mycoplasmas was made possible by adopting a parasitic mode of life. The supply of nutrients from their hosts apparently enabled mycoplasmas to lose, during evolution, the genes for many assimilative processes. During their evolution and adaptation to a parasitic mode of life, the mycoplasmas have developed various genetic systems providing a highly plastic set of variable surface proteins to evade the host immune system. The uniqueness of the mycoplasmal systems is manifested by the presence of highly mutable modules combined with an ability to expand the antigenic repertoire by generating structural alternatives, all compressed into limited genomic sequences. In the absence of a cell wall and a periplasmic space, the majority of surface variable antigens in mycoplasmas are lipoproteins. Apart from providing specific antimycoplasmal defense, the host immune system is also involved in the development of pathogenic lesions and exacerbation of mycoplasma induced diseases. Mycoplasmas are

  13. Mycoplasmas, plants, insect vectors: a matrimonial triangle.

    PubMed

    Garnier, M; Foissac, X; Gaurivaud, P; Laigret, F; Renaudin, J; Saillard, C; Bové, J M

    2001-10-01

    Plant pathogenic mycoplasmas were discovered by electron microscopy, in 1967, long after the discovery and culture in 1898 of the first pathogenic mycoplasma of animal origin, Mycoplasma mycoides. Mycoplasmas are Eubacteria of the class Mollicutes, a group of organisms phylogenetically related to Gram-positive bacteria. Their more characteristic features reside in the small size of their genomes, the low guanine (G) plus cytosine (C) content of their genomic DNA and the lack of a cell wall. Plant pathogenic mycoplasmas are responsible for several hundred diseases and belong to two groups: the phytoplasmas and the spiroplasmas. The phytoplasmas (previously called MLOs, for mycoplasma like organisms) were discovered first; they are pleiomorphic, and have so far resisted in vitro cultivation. Phytoplasmas represent the largest group of plant pathogenic Mollicutes. Only three plant pathogenic spiroplasmas are known today. Spiroplasma citri, the agent of citrus stubborn was discovered and cultured in 1970 and shown to be helical and motile. S. kunkelii is the causal agent of corn stunt. S. phoeniceum, responsible for periwinkle yellows, was discovered in Syria. There are many other spiroplasmas associated with insects and ticks. Plant pathogenic mycoplasmas are restricted to the phloem sieve tubes in which circulates the photosynthetically-enriched sap, the food for many phloem-feeding insects (aphids, leafhoppers, psyllids, etc.). Interestingly, phytopathogenic mycoplasmas are very specifically transmitted by leafhoppers or psyllid species. In this paper, the most recent knowledge on phytopathogenic mycoplasmas in relation with their insect and plant habitats is presented as well as the experiments carried out to control plant mycoplasma diseases, by expression of mycoplasma-directed-antibodies in plants (plantibodies).

  14. Characteristics of Mycoplasma hominis adhesion.

    PubMed Central

    Olson, L D; Gilbert, A A

    1993-01-01

    Mycoplasma hominis, a human pathogen, has previously been observed to bind to sulfatide separated on thin-layer chromatograms. It has not been demonstrated, however, that the binding is not simply a nonspecific ionic interaction. The ability of a low-passage patient isolate of M. hominis to adhere to glycoconjugates other than sulfatide and the characteristics of its binding to sulfatide were studied. Mycoplasmas were found to bind strongly and specifically in a temperature- and dose-dependent manner to only sulfatide of all of the glycolipids and glycoproteins tested. The avidity and specificity of binding, as well as the ability to inhibit the interaction specifically, suggest that the receptors to which M. hominis binds, particularly in the human urogenital tract, from which it is frequently isolated, are primarily, if not solely, sulfated glycolipids. Images PMID:8491739

  15. Aerodynamic flight performance in flap-gliding birds and bats.

    PubMed

    Muijres, Florian T; Henningsson, Per; Stuiver, Melanie; Hedenström, Anders

    2012-08-07

    Many birds use a flight mode called undulating or flap-gliding flight, where they alternate between flapping and gliding phases, while only a few bats make use of such a flight mode. Among birds, flap-gliding is commonly used by medium to large species, where it is regarded to have a lower energetic cost than continuously flapping flight. Here, we introduce a novel model for estimating the energetic flight economy of flap-gliding animals, by determining the lift-to-drag ratio for flap-gliding based on empirical lift-to-drag ratio estimates for continuous flapping flight and for continuous gliding flight, respectively. We apply the model to flight performance data of the common swift (Apus apus) and of the lesser long-nosed bat (Leptonycteris yerbabuenae). The common swift is a typical flap-glider while-to the best of our knowledge-the lesser long-nosed bat does not use flap-gliding. The results show that, according to the model, the flap-gliding common swift saves up to 15% energy compared to a continuous flapping swift, and that this is primarily due to the exceptionally high lift-to-drag ratio in gliding flight relative to that in flapping flight for common swifts. The lesser long-nosed bat, on the other hand, seems not to be able to reduce energetic costs by flap-gliding. The difference in relative costs of flap-gliding flight between the common swift and the lesser long-nosed bat can be explained by differences in morphology, flight style and wake dynamics. The model presented here proves to be a valuable tool for estimating energetic flight economy in flap-gliding animals. The results show that flap-gliding flight that is naturally used by common swifts is indeed the most economic one of the two flight modes, while this is not the case for the non-flap-gliding lesser long-nosed bat. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 21 CFR 610.30 - Test for Mycoplasma.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Test for Mycoplasma. 610.30 Section 610.30 Food... GENERAL BIOLOGICAL PRODUCTS STANDARDS Mycoplasma § 610.30 Test for Mycoplasma. Except as provided... tested for the presence of Mycoplasma, as follows: Samples of the virus for this test shall be...

  17. 21 CFR 610.30 - Test for Mycoplasma.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Test for Mycoplasma. 610.30 Section 610.30 Food... GENERAL BIOLOGICAL PRODUCTS STANDARDS Mycoplasma § 610.30 Test for Mycoplasma. Except as provided... tested for the presence of Mycoplasma, as follows: Samples of the virus for this test shall be...

  18. Mycoplasma genitalium in Toronto, Ont

    PubMed Central

    Gesink, Dionne; Racey, C. Sarai; Seah, Christine; Zittermann, Sandra; Mitterni, Leo; Juzkiw, Jerry; Jamieson, Heather; Greer, Jane; Singh, Sudesh; Jensen, Jørgen Skov; Allen, Vanessa

    2016-01-01

    Objective To estimate the prevalence of Mycoplasma genitalium in Toronto, Ont; detect mutations associated with macrolide and fluoroquinolone resistance; and describe treatment outcomes. Design Prospective, cross-sectional study. Setting A sexual health clinic in Toronto. Participants A consecutive sample of men and women attending the sexual health clinic between September 1, 2013, and December 20, 2013. Interventions Participants underwent testing for M genitalium, along with standard sexually transmitted infection screening. All samples that had positive results for M genitalium were tested for mutations associated with resistance to macrolides and fluoroquinolones. Mycoplasma genitalium treatment was based on resistance profile and verified with a test of cure. Main outcome measures Positive results for M genitalium and antibiotic resistance. Results A total of 1193 men and women participated in the study. Overall, 4.5% of the 884 men and 3.2% of the 309 women had positive test results for M genitalium. Asymptomatic infection was common (52.0%). Macrolide resistance–mediating mutations were found in 58.0% of the M genitalium infections. No treatment failure was observed for azithromycin-treated cases. Treatment failure was suspected for 16.7% of cases treated with moxifloxacin. Conclusion Mycoplasma genitalium is present in Canada, with a prevalence comparable to chlamydia and gonorrhea, and has high macrolide and fluoroquinolone resistance. PMID:27331225

  19. Submasseteric abscess caused by Mycoplasma salivarium infection.

    PubMed

    Grisold, Andrea J; Hoenigl, Martin; Leitner, Eva; Jakse, Klaus; Feierl, Gebhard; Raggam, Reinhard B; Marth, Egon

    2008-11-01

    Mycoplasma salivarium preferentially resides in the human oral cavity. Unlike other Mycoplasma species, M. salivarium has not been regarded as a pathogen, although one case of M. salivarium-caused arthritis in a patient with hypogammaglobulinemia has been reported. We describe the first case of submasseteric abscess caused by M. salivarium.

  20. Bilateral optic papillitis following mycoplasma pneumoniae pneumonia.

    PubMed

    Milla, E; Zografos, L; Piguet, B

    1998-01-01

    Mycoplasma pneumoniae is an atypical bacterium that can cause a great variety of respiratory infections and be responsible for ocular involvement such as conjunctivitis, anterior uveitis and very rarely optic neuropathy. We report herein an additional case of bilateral optic disc swelling with profound visual loss following Mycoplasma pneumoniae pneumonia and review the world literature on the ocular manifestations associated with this pathogen.

  1. One test microbial diagnostic microarray for identification of Mycoplasma mycoides subsp. mycoides and other Mycoplasma species.

    PubMed

    Tonelli, A; Sacchini, F; Krasteva, I; Zilli, K; Scacchia, M; Beaurepaire, C; Nantel, A; Pini, A

    2012-11-01

    The present study describes the use of microarray technology for rapid identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. A microarray containing genetic sequences of 55 different bacterial species from Acholeplasma, Mycoplasma, Spiroplasma and Ureaplasma genera was constructed. Sequences to genes of interest were collected in FASTA format from NCBI. The collected sequences were processed with OligoPicker software. Oligonucleotides were then checked for their selectivity with BLAST searches in GenBank. The microarray was tested with ATCC/NCTC strains of Mycoplasma spp. of veterinary importance in ruminants including Mycoplasma belonging to the mycoides cluster as well as Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri field strains. The results showed that but one ATCC/NCTC reference strains hybridized with their species-specific sequences showed a profile/signature different and distinct from each other. The heat-map of the hybridization results for the nine genes interrogated for Mycoplasma mycoides subsp. mycoides demonstrated that the reference strain Mycoplasma mycoides subsp mycoides PG1 was positive for all of the gene sequences spotted on the microarray. CBPP field, vaccine and reference strains were all typed to be M. mycoides subsp. mycoides, and seven of the nine strains gave positive hybridization results for all of the nine genes. Two Italian strains were negative for some of the genes. Comparison with non-Mycoplasma mycoides subsp. mycoides reference strains showed some positive signals or considerable homology to Mycoplasma mycoides subsp. mycoides genes. As expected, some correlations were observed between the strictly genetically and antigenically correlated Mycoplasma mycoides subsp. mycoides and

  2. Eradication of Mycoplasma contaminations from cell cultures.

    PubMed

    Uphoff, Cord C; Drexler, Hans G

    2014-04-14

    Mycoplasma contaminations have a multitude of effects on cultured cell lines that may influence the results of experiments or pollute bioactive substances isolated from the eukaryotic cells. The elimination of mycoplasma contaminations from cell cultures with antibiotics has been proven to be a practical alternative to discarding and re-establishing important or irreplaceable cell lines. Different fluoroquinolones, tetracyclins, pleuromutilins, and macrolides shown to have strong anti-mycoplasma properties are employed for the decontamination. These antibiotics are applied as single treatments, as combination treatment of two antibiotics in parallel or successively, or in combination with a surface-active peptide to enhance the action of the antibiotic. The protocols in this unit allow eradication of mycoplasmas, prevention of the development of resistant mycoplasma strains, and potential cure of heavily contaminated and damaged cells. Consistent and permanent alterations to eukaryotic cells attributable to the treatment have not been demonstrated.

  3. Mycoplasma penetrans and Other Mycoplasmas in Urine of Human Immunodeficiency Virus-Positive Children

    PubMed Central

    Hussain, Althaf I.; Robson, William Lane M.; Kelley, Robin; Reid, Tanya; Gangemi, J. David

    1999-01-01

    Urine samples from children with human immunodeficiency virus (HIV) infection and healthy controls were examined for mycoplasmas by culture. Standard biochemical assays, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and PCR (16S and 16S-23S spacer rRNA region) were used for identification of isolates. Mycoplasmas were identified from 13 (87%) of 15 HIV-positive patients and 3 (20%) of 15 HIV-negative control patients. The frequency and type of mycoplasma varied with the severity of HIV infection. Mycoplasma penetrans, Mycoplasma pirum, Mycoplasma fermentans, and Mycoplasma genitalium were isolated from patients with severe immunodeficiency. Mycoplasma hominis and Ureaplasma urealyticum were isolated more frequently from children in the early stages of HIV infection and from HIV-negative patients. Mycoplasma penetrans was isolated from one (50%) of two patients in Centers for Disease Control and Prevention (CDC) group B and from five (55.5%) of nine pediatric patients with AIDS (CDC group C). This is the first report that indicates that “AIDS-associated” mycoplasmas are more common in HIV-infected children than in HIV-negative controls. PMID:10203515

  4. Electrical charging of skis gliding on snow.

    PubMed

    Colbeck, S C

    1995-01-01

    Ski charging was measured using giant-slalom style skis as gliding capacitors. The voltage measured across the plates was proportional to the charge on the base. While resting on dry snow or suspended in the air, the voltage was slowly reduced by the data logger itself. On wet snow the decay was much faster. While stationary on powder snow the ski developed a slightly negative voltage, showed a small, transient positive peak when motion began, rapidly dropped to negative values, and then assumed a quasi-steady climb to positive voltages. A great deal of noise was superimposed on the general features of the signal when skiing on hard or bumpy surfaces. Thus, the accumulation of charge to high levels was only possible with long runs in deep powder. The rate of charging increased with speed but was not affected by use of one "antistatic" wax, and another such wax actually increased the measured voltage over that of an unwaxed base.

  5. Floquet topological phases protected by time glide symmetry

    NASA Astrophysics Data System (ADS)

    Morimoto, Takahiro; Po, Hoi Chun; Vishwanath, Ashvin

    2017-05-01

    We study Floquet topological phases in periodically driven systems that are protected by "time glide symmetry", a combination of reflection and half time period translation. Time glide symmetry is an analog of glide symmetry with partial time translation replacing the partial space translation and, hence, is an intrinsically dynamical symmetry which may be engineered in periodically driven systems by exploiting the controllability of driving. We present lattice models of time glide symmetric Floquet topological insulators in two and three dimensions. The topological numbers characterizing those Floquet topological phases are derived from the half-period time-evolution operator along with time glide operator. Moreover, we classify Floquet topological phases protected by time glide symmetry in general dimensions using a Clifford algebra approach. The obtained classification table is similar to that for topological crystalline insulators protected by static reflection symmetry, but shows nontrivial entries in different combination of symmetries, which clarifies that time glide symmetric Floquet topological phases are a distinct set of topological phases from topological crystalline insulators. We also classify Floquet topological phases with "time screw symmetry", defined as a twofold spatial rotation accompanied by half-period time translation.

  6. Degradation of Verapamil hydrochloride in water by gliding arc discharge.

    PubMed

    Krishna, Syam; Maslani, Alan; Izdebski, Tomasz; Horakova, Marta; Klementova, Sarka; Spatenka, Petr

    2016-06-01

    This study investigated the influence of gliding arc plasma discharge on the degradation of Verapamil hydrochloride in water. The plasma discharge was characterized by means of optical emission spectroscopy. Spectra of various atomic and molecular species were observed. Aqueous solution of Verapamil hydrochloride was exposed to gliding arc discharge operated in continuous discharge at atmospheric pressure and room temperature. The identification of Verapamil, the degradation mechanisms of Verapamil and its transformation products were performed using liquid chromatography - mass spectrometry (HPLC-MS). Experimental results indicate that the atmospheric pressure gliding arc plasma treatment has noticeable effects on Verapamil with satisfactory degradation efficiency. Plausible mechanisms of the degradation were discussed.

  7. Co-infection with Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' in three cats from Brazil.

    PubMed

    de Morais, Helio A; Guimarães, Ana Marcia S; Vidotto, Odilon; Baumann, Aline; Biondo, Alexander W; Messick, Joanne B

    2007-12-01

    The two most common haemotropic Mycoplasma of cats, Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' have been identified using molecular techniques in all continents, except Antarctica. We report the first molecular characterization in South America of a dual infection with M haemofelis and 'Candidatus Mycoplasma haemominutum' in three domestic cats. The 16S ribosomal RNA gene was amplified in three anaemic cats in which haemoplasma organisms were seen attached to the erythrocytes in the peripheral blood smear. Bands of the expected size for M haemofelis and 'Candidatus Mycoplasma haemominutum' were observed in all three cats. The 393 bp segment of one of the amplicons had a similarity value of 100% to M haemofelis, whereas the other amplicon, a 192 bp segment, was 100% similar to 'Candidatus Mycoplasma haemominutum'. After diagnosis, two cats received blood transfusion and they were all treated with doxycycline. All three cats recovered uneventfully.

  8. Detection of Mycoplasma canadense and Mycoplasma californicum in dairy cattle from Argentina.

    PubMed

    Tamiozzo, Pablo J; Estanguet, Abel A; Maito, Julia; Tirante, Liliana; Pol, Martin; Giraudo, José A

    2014-01-01

    Different species of Mycoplasma can affect bovine cattle, causing several diseases. PCR sequencing and further analysis of the 16S-23S rRNA ITS region have shown a significant interspecies variability among Mollicutes. Sixteen suspected isolates of Mycoplasma spp. obtained from milk samples from dairy herds were amplified (16S-23S rRNA ITS region). Fourteen out of those 16 suspected Mycoplasma spp. isolates were PCR-positive. To confirm the identity of Mycoplasma bovis, these 14 isolates were tested by another species-specific PCR. Seven of the isolates rendered a positive result. The products of 16S-23S rRNA ITS PCR from one isolate that was identified as M. bovis and from two other isolates, identified as non- M. bovis were randomly selected, sequenced and analyzed. The three sequences (A, B and C) showed 100% similarity with M. bovis, Mycoplasma canadense and Mycoplasma californicum respectively.

  9. Sedimentation counting and morphology of Mycoplasma.

    PubMed

    Clark, H W

    1965-11-01

    Clark, Harold W. (The George Washington University School of Medicine, Washington, D.C.). Sedimentation counting and morphology of Mycoplasma. J. Bacteriol. 90:1373-1386. 1965.-The sedimentation technique for counting viral particles was applied to the quantitation and morphological identification of Mycoplasma in broth cultures. Mycoplasma, apparently in their native form, firmly adhered to the surface, when sedimented on glass cover slips or onto electron microscope grids. The sedimented cover slip preparations stained with crystal violet could be readily counted in the light microscope. The cultures sedimented onto electron microscope grids were readily counted at low magnification and provided excellent preparations for morphological examination at higher magnifications. It was found that air-dried Mycoplasma particles were enlarged considerably because of excessive flattening. Fixation of sedimented Mycoplasma particles in diluted OsO(4) prior to air drying yielded a more realistic morphology, with various sizes and shapes in the stages of the growth cycle exhibited. A new technique of differentially staining Mycoplasma colonies on agar plates was developed to facilitate the quantitation of viable colony-forming units for comparison with total counts. The use of plastic or Parafilm gaskets for dry mounting was developed to facilitate the handling and examination of the stained cover slip preparations. The results of this investigation indicated that the growth cycle of some Mycoplasma species includes a stage of hexadic fission with the cleavage of minimal reproductive units (less than 100 mmu) containing a limited deoxyribonucleic acid genetic coding molecule (approximately 4 x 10(6)).

  10. Optimized PCR-based detection of mycoplasma.

    PubMed

    Dobrovolny, Paige L; Bess, Dan

    2011-06-20

    The maintenance of contamination-free cell lines is essential to cell-based research. Among the biggest contaminant concerns are mycoplasma contamination. Although mycoplasma do not usually kill contaminated cells, they are difficult to detect and can cause a variety of effects on cultured cells, including altered metabolism, slowed proliferation and chromosomal aberrations. In short, mycoplasma contamination compromises the value of those cell lines in providing accurate data for life science research. The sources of mycoplasma contamination in the laboratory are very challenging to completely control. As certain mycoplasma species are found on human skin, they can be introduced through poor aseptic technique. Additionally, they can come from contaminated supplements such as fetal bovine serum, and most importantly from other contaminated cell cultures. Once mycoplasma contaminates a culture, it can quickly spread to contaminate other areas of the lab. Strict adherence to good laboratory practices such as good aseptic technique are key, and routine testing for mycoplasma is highly recommended for successful control of mycoplasma contamination. PCR-based detection of mycoplasma has become a very popular method for routine cell line maintenance. PCR-based detection methods are highly sensitive and can provide rapid results, which allows researchers to respond quickly to isolate and eliminate contamination once it is detected in comparison to the time required using microbiological techniques. The LookOut Mycoplasma PCR Detection Kit is highly sensitive, with a detection limit of only 2 genomes per μl. Taking advantage of the highly specific JumpStart Taq DNA Polymerase and a proprietary primer design, false positives are greatly reduced. The convenient 8-tube format, strips pre-coated with dNTPs, and associated primers helps increase the throughput to meet the needs of customers with larger collections of cell lines. Given the extreme sensitivity of the kit, great

  11. Substrate-induced gliding in a nematic liquid crystal layer

    NASA Astrophysics Data System (ADS)

    Mema, E.; Kondic, L.; Cummings, L. J.

    2015-12-01

    We consider the interaction between nematic liquid crystals (NLCs) and polymer substrates. Such substrates can interact with NLCs, exhibiting a phenomenon known as director gliding: the preferred orientation of the NLC molecules at the interface changes on time scales that are slow relative to the elastic relaxation time scale of the NLC. We present two models for gliding, inspired by experiments that investigate the interaction between the NLC and a polymer substrate. These models, though simple, lead to nontrivial results, including loss of bistability under gliding. Perhaps surprisingly, we find that externally imposed switching between the steady states of a bistable system may reverse the effect of gliding, preventing loss of bistability if switching is sufficiently frequent. Our findings may be of relevance to a variety of technological applications involving liquid crystal devices, and particularly to a new generation of flexible liquid crystal displays that implement polymeric substrates.

  12. Mobilization

    DTIC Science & Technology

    1987-01-01

    istic and romantic emotionalism that typifies this genre. Longino, James C., et al. “A Study of World War Procurement and Industrial Mobilization...States. Harrisburg, PA: Military Service Publishing Co., 1941. CARL 355.22 J72b. Written in rough prose , this World War II era document explains the

  13. Nonlinear stability and control of gliding vehicles

    NASA Astrophysics Data System (ADS)

    Bhatta, Pradeep

    In this thesis we use nonlinear systems analysis to study dynamics and design control solutions for vehicles subject to hydrodynamic or aerodynamic forcing. Application of energy-based methods for such vehicles is challenging due to the presence of energy-conserving lift and side forces. We study how the lift force determines the geometric structure of vehicle dynamics. A Hamiltonian formulation of the integrable phugoid-mode equations provides a Lyapunov function candidate, which is used throughout the thesis for deriving equilibrium stability results and designing stabilizing control laws. A strong motivation for our work is the emergence of underwater gliders as an important observation platform for oceanography. Underwater gliders rely on buoyancy regulation and internal mass redistribution for motion control. These vehicles are attractive because they are designed to operate autonomously and continuously for several weeks. The results presented in this thesis contribute toward the development of systematic control design procedures for extending the range of provably stable maneuvers of the underwater glider. As the first major contribution we derive conditions for nonlinear stability of longitudinal steady gliding motions using singular perturbation theory. Stability is proved using a composite Lyapunov function, composed of individual Lyapunov functions that prove stability of rotational and translational subsystem equilibria. We use the composite Lyapunov function to design control laws for stabilizing desired relative equilibria in different actuation configurations for the underwater glider. We propose an approximate trajectory tracking method for an aircraft model. Our method uses exponential stability results of controllable steady gliding motions, derived by interpreting the aircraft dynamics as an interconnected system of rotational and translational subsystems. We prove bounded position error for tracking prescribed, straight-line trajectories, and

  14. Acoustic emission at interaction of gliding deformation with point obstacles

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskii, V. V.; Panin, I. G.

    2017-08-01

    The mathematical model of dislocation glide movement is used to calculate the signal of acoustic emission that accompanies the defect overcoming in a crystal. The elastic stress in the emitted signal is estimated. It is established that the acoustic emission signal in the case of dislocation separation from a defect substantially exceeds the signal in the case of deceleration of a gliding dislocation on a defect. The shapes of these signals also differ.

  15. Illusory continuity without sufficient sound energy to fill a temporal gap: examples of crossing glide tones.

    PubMed

    Kuroda, Tsuyoshi; Nakajima, Yoshitaka; Eguchi, Shuntarou

    2012-10-01

    The gap transfer illusion is an auditory illusion where a temporal gap inserted in a longer glide tone is perceived as if it were in a crossing shorter glide tone. Psychophysical and phenomenological experiments were conducted to examine the effects of sound-pressure-level (SPL) differences between crossing glides on the occurrence of the gap transfer illusion. We found that the subjective continuity-discontinuity of the crossing glides changed as a function of the relative level of the shorter glide to the level of the longer glide. When the relative level was approximately between -9 and +2 dB, listeners perceived the longer glide as continuous and the shorter glide as discontinuous, that is, the gap transfer illusion took place. The glides were perceived veridically below this range, that is, gap transfer did not take place, whereas above this range the longer glide and the shorter glide were both perceived as continuous. The fact that the longer glide could be perceived as continuous even when the crossing shorter glide was 9 dB weaker indicates that the longer glide's subjective continuity cannot be explained within the conventional framework of auditory organization, which assumes reallocation of sound energy from the shorter to the longer glide. The implicated mechanisms are discussed in terms of the temporal configuration of onsets and terminations and the time-frequency distribution of sound energy.

  16. Soaring energetics and glide performance in a moving atmosphere

    PubMed Central

    Reynolds, Kate V.; Thomas, Adrian L. R.

    2016-01-01

    Here, we analyse the energetics, performance and optimization of flight in a moving atmosphere. We begin by deriving a succinct expression describing all of the mechanical energy flows associated with gliding, dynamic soaring and thermal soaring, which we use to explore the optimization of gliding in an arbitrary wind. We use this optimization to revisit the classical theory of the glide polar, which we expand upon in two significant ways. First, we compare the predictions of the glide polar for different species under the various published models. Second, we derive a glide optimization chart that maps every combination of headwind and updraft speed to the unique combination of airspeed and inertial sink rate at which the aerodynamic cost of transport is expected to be minimized. With these theoretical tools in hand, we test their predictions using empirical data collected from a captive steppe eagle (Aquila nipalensis) carrying an inertial measurement unit, global positioning system, barometer and pitot tube. We show that the bird adjusts airspeed in relation to headwind speed as expected if it were seeking to minimize its aerodynamic cost of transport, but find only weak evidence to suggest that it adjusts airspeed similarly in response to updrafts during straight and interthermal glides. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528788

  17. Glide back booster wind tunnel model testing

    NASA Astrophysics Data System (ADS)

    Pricop, M. V.; Cojocaru, M. G.; Stoica, C. I.; Niculescu, M. L.; Neculaescu, A. M.; Persinaru, A. G.; Boscoianu, M.

    2017-07-01

    Affordable space access requires partial or ideally full launch vehicle reuse, which is in line with clean environment requirement. Although the idea is old, the practical use is difficult, requiring very large technology investment for qualification. Rocket gliders like Space Shuttle have been successfullyoperated but the price and correspondingly the energy footprint were found not sustainable. For medium launchers, finally there is a very promising platform as Falcon 9. For very small launchers the situation is more complex, because the performance index (payload to start mass) is already small, versus medium and heavy launchers. For partial reusable micro launchers this index is even smaller. However the challenge has to be taken because it is likely that in a multiyear effort, technology is going to enable the performance recovery to make such a system economically and environmentally feasible. The current paper is devoted to a small unitary glide back booster which is foreseen to be assembled in a number of possible configurations. Although the level of analysis is not deep, the solution is analyzed from the aerodynamic point of view. A wind tunnel model is designed, with an active canard, to enablea more efficient wind tunnel campaign, as a national level premiere.

  18. A College Epidemic of Mycoplasma Pneumoniae.

    ERIC Educational Resources Information Center

    Ralston, David; Cochran, Burt

    1979-01-01

    The article reports on an outbreak of mycoplasma pneumoniae at the California Polytechnic State University including a historical background of the disease, clinical features, laboratory findings for treated patients, treatment, and clinical clues for diagnosis. (JMF)

  19. Mycoplasma penetrans bacteremia and primary antiphospholipid syndrome.

    PubMed Central

    Yáñez, A.; Cedillo, L.; Neyrolles, O.; Alonso, E.; Prévost, M. C.; Rojas, J.; Watson, H. L.; Blanchard, A.; Cassell, G. H.

    1999-01-01

    Mycoplasma penetrans, a rare bacterium so far only found in HIV-infected persons, was isolated in the blood and throat of a non-HIV-infected patient with primary antiphospholipid syndrome (whose etiology and pathogenesis are unknown). PMID:10081687

  20. Survey of plasmids in various mycoplasmas.

    PubMed Central

    Harasawa, R.; Barile, M. F.

    1983-01-01

    Thirty-three strains representing 15 distinct Mycoplasma, Acholeplasma, and Spiroplasma species were examined for the presence of plasmid DNA by agarose gel electrophoresis. The electrophoretic patterns of the DNAs of three strains, Mycoplasma sp. strain 747, Spiroplasma mirum strain SMCA, and M. hominis strain 1257, suggested the presence of a plasmid with molecular weights of approximately 70, 10, and 9 megadaltons, respectively. The functions of these plasmids are currently unknown. Images FIG. 1 PMID:6679154

  1. Detection and prevention of mycoplasma hominis infection

    DOEpatents

    DelVecchio, Vito G.; Gallia, Gary L.; McCleskey, Ferne K.

    1997-01-21

    The present invention is directed to a rapid and sensitive method for detecting Mycoplasma hominis using M. hominis-specific probes, oligonucleotides or antibodies. In particular a target sequence can be amplified by in vitro nucleic acid amplification techniques, detected by nucleic acid hybridization using the subject probes and oligonucleotides or detected by immunoassay using M. hominis-specific antibodies. M. hominis-specific nucleic acids which do not recognize or hybridize to genomic nucleic acid of other Mycoplasma species are also provided.

  2. Gliding flight in Chrysopelea: turning a snake into a wing.

    PubMed

    Socha, John J

    2011-12-01

    Although many cylindrical animals swim through water, flying snakes of the genus Chrysopelea are the only limbless animals that glide through air. Despite a lack of limbs, these snakes can actively launch by jumping, maintain a stable glide path without obvious control surfaces, maneuver, and safely land without injury. Jumping takeoffs employ vertically looped kinematics that seem to be different than any other behavior in limbless vertebrates, and their presence in a closely related genus suggests that gap-crossing may have been a behavioral precursor to the evolution of gliding in snakes. Change in shape of the body by dorsoventral flattening and high-amplitude aerial undulation comprise two key features of snakes' gliding behavior. As the snake becomes airborne, the body flattens sequentially from head to vent, forming a cross-sectional shape that is roughly triangular, with a flat surface and lateral "lips" that protrude ventrally on each side of the body; these may diminish toward the vent. This shape likely provides the snake with lift coefficients that peak at high angles of attack and gentle stall characteristics. A glide trajectory is initiated with the snake falling at a steep angle. As the snake rotates in the pitch axis, it forms a wide "S" shape and begins undulating in a complex three-dimensional pattern, with the body angled upward relative to the glide path. The head moves side-to-side, sending traveling waves posteriorly toward the tail, while the body (most prominently, the posterior end) oscillates in the vertical axis. These active movements while gliding are substantially different and more dynamic than those used by any other animal glider. As the snake gains forward speed, the glide path becomes less steep, reaching minimally recorded glide angles of 13°. In general, smaller snakes appear to be more proficient gliders. Chrysopelea paradisi can also maneuver and land either on the ground or on vegetation, but these locomotor behaviors have

  3. Mycoplasmas and Ureaplasmas as Neonatal Pathogens

    PubMed Central

    Waites, Ken B.; Katz, Brenda; Schelonka, Robert L.

    2005-01-01

    The genital mycoplasmas represent a complex and unique group of microorganisms that have been associated with a wide array of infectious diseases in adults and infants. The lack of conclusive knowledge regarding the pathogenic potential of Mycoplasma and Ureaplasma spp. in many conditions is due to a general unfamiliarity of physicians and microbiology laboratories with their fastidious growth requirements, leading to difficulty in their detection; their high prevalence in healthy persons; the poor design of research studies attempting to base association with disease on the mere presence of the organisms in the lower urogenital tract; the failure to consider multifactorial aspects of diseases; and considering these genital mycoplasmas only as a last resort. The situation is now changing because of a greater appreciation of the genital mycoplasmas as perinatal pathogens and improvements in laboratory detection, particularly with regard to the development of powerful molecular nucleic acid amplification tests. This review summarizes the epidemiology of genital mycoplasmas as causes of neonatal infections and premature birth; evidence linking ureaplasmas with bronchopulmonary dysplasia; recent changes in the taxonomy of the genus Ureaplasma; the neonatal host response to mycoplasma and ureaplasma infections; advances in laboratory detection, including molecular methods; and therapeutic considerations for treatment of systemic diseases. PMID:16223956

  4. Molecular detection of Mycoplasma wenyonii and 'Candidatus Mycoplasma haemobos' in cattle in Hokkaido, Japan.

    PubMed

    Tagawa, Michihito; Matsumoto, Kotaro; Inokuma, Hisashi

    2008-11-25

    Blood samples from 78 cattle were tested for hemoplasma infection using molecular methods. PCR and sequence analysis revealed that 17 cattle were infected with Mycoplasma wenyonii, while 13 were infected with 'Candidatus Mycoplasma haemobos'. Four animals were infected with both species. This is the first study to report hemoplasma species infection among cattle in Japan.

  5. Gliding Motility in Bacteria: Insights from Studies of Myxococcus xanthus

    PubMed Central

    Spormann, Alfred M.

    1999-01-01

    Gliding motility is observed in a large variety of phylogenetically unrelated bacteria. Gliding provides a means for microbes to travel in environments with a low water content, such as might be found in biofilms, microbial mats, and soil. Gliding is defined as the movement of a cell on a surface in the direction of the long axis of the cell. Because this definition is operational and not mechanistic, the underlying molecular motor(s) may be quite different in diverse microbes. In fact, studies on the gliding bacterium Myxococcus xanthus suggest that two independent gliding machineries, encoded by two multigene systems, operate in this microorganism. One machinery, which allows individual cells to glide on a surface, independent of whether the cells are moving alone or in groups, requires the function of the genes of the A-motility system. More than 37 A-motility genes are known to be required for this form of movement. Depending on an additional phenotype, these genes are divided into two subclasses, the agl and cgl genes. Videomicroscopic studies on gliding movement, as well as ultrastructural observations of two myxobacteria, suggest that the A-system motor may consist of multiple single motor elements that are arrayed along the entire cell body. Each motor element is proposed to be localized to the periplasmic space and to be anchored to the peptidoglycan layer. The force to glide which may be generated here is coupled to adhesion sites that move freely in the outer membrane. These adhesion sites provide a specific contact with the substratum. Based on single-cell observations, similar models have been proposed to operate in the unrelated gliding bacteria Flavobacterium johnsoniae (formerly Cytophaga johnsonae), Cytophaga strain U67, and Flexibacter polymorphus (a filamentous glider). Although this model has not been verified experimentally, M. xanthus seems to be the ideal organism with which to test it, given the genetic tools available. The second gliding

  6. Gliding motility in bacteria: insights from studies of Myxococcus xanthus.

    PubMed

    Spormann, A M

    1999-09-01

    Gliding motility is observed in a large variety of phylogenetically unrelated bacteria. Gliding provides a means for microbes to travel in environments with a low water content, such as might be found in biofilms, microbial mats, and soil. Gliding is defined as the movement of a cell on a surface in the direction of the long axis of the cell. Because this definition is operational and not mechanistic, the underlying molecular motor(s) may be quite different in diverse microbes. In fact, studies on the gliding bacterium Myxococcus xanthus suggest that two independent gliding machineries, encoded by two multigene systems, operate in this microorganism. One machinery, which allows individual cells to glide on a surface, independent of whether the cells are moving alone or in groups, requires the function of the genes of the A-motility system. More than 37 A-motility genes are known to be required for this form of movement. Depending on an additional phenotype, these genes are divided into two subclasses, the agl and cgl genes. Videomicroscopic studies on gliding movement, as well as ultrastructural observations of two myxobacteria, suggest that the A-system motor may consist of multiple single motor elements that are arrayed along the entire cell body. Each motor element is proposed to be localized to the periplasmic space and to be anchored to the peptidoglycan layer. The force to glide which may be generated here is coupled to adhesion sites that move freely in the outer membrane. These adhesion sites provide a specific contact with the substratum. Based on single-cell observations, similar models have been proposed to operate in the unrelated gliding bacteria Flavobacterium johnsoniae (formerly Cytophaga johnsonae), Cytophaga strain U67, and Flexibacter polymorphus (a filamentous glider). Although this model has not been verified experimentally, M. xanthus seems to be the ideal organism with which to test it, given the genetic tools available. The second gliding

  7. Genome Sequence of Mycoplasma hyorhinis Isolated from Cell Cultures

    PubMed Central

    Cibulski, Samuel Paulo; Siqueira, Franciele Maboni; Teixeira, Thais Fumaco; Mayer, Fabiana Quoos; Almeida, Luiz Gonzaga

    2016-01-01

    Mycoplasmas are major contaminants of mammalian cell cultures. Here, the complete genome sequence of Mycoplasma hyorhinis recovered from Madin-Darby bovine kidney (MDBK) cells is reported. PMID:27738034

  8. [Mycoplasma Pneumoniae-Induced Meningoencephalitis].

    PubMed

    Özel, C; Dafotakis, M; Nikoubashman, O; Litmathe, J; Matz, O; Schöne, U

    2015-07-01

    In clinical practice, secondary infections of the central nervous system (CNS) represent rare yet severe complications of their respective primary infections. In this case report, we describe a 22-year-old patient with a medical history of Asthma bronchiale, who developed significant neurological deficits after a respiratory infection. The neurological symptoms progressed despite antibiotic therapy with vancomycin, ampicillin and ceftriaxone. The patient's cerebrospinal fluid and a cranial magnetic resonance imaging (MRI) furnished evidence of acute meningoencephalitis. Microbiological assessment confirmed an acute mycoplasma pneumonia infection. Changing the patient's antibiotic regimen to minocycline and prednisolone led to significant clinical improvement. Pathomechanisms and therapeutic options to treat meningoencephalitis will be discussed in the following. © Georg Thieme Verlag KG Stuttgart · New York.

  9. A "hydrokinematic" method of measuring the glide efficiency of a human swimmer.

    PubMed

    Naemi, Roozbeh; Sanders, Ross H

    2008-12-01

    The aim of this study was to develop and test a method of quantifying the glide efficiency, defined as the ability of the body to maintain its velocity over time and to minimize deceleration through a rectilinear glide. The glide efficiency should be determined in a way that accounts for both the inertial and resistive characteristics of the gliding body as well as the instantaneous velocity. A displacement function (parametric curve) was obtained from the equation of motion of the body during a horizontal rectilinear glide. The values of the parameters in the displacement curve that provide the best fit to the displacement-time data of a body during a rectilinear horizontal glide represent the glide factor and the initial velocity of the particular glide interval. The glide factor is a measure of glide efficiency and indicates the ability of the body to minimize deceleration at each corresponding velocity. The glide efficiency depends on the hydrodynamic characteristic of the body, which is influenced by the body's shape as well as by the body's size. To distinguish the effects of size and shape on the glide efficiency, a size-related glide constant and a shape-related glide coefficient were determined as separate entities. The glide factor is the product of these two parameters. The goodness of fit statistics indicated that the representative displacement function found for each glide interval closely represents the real displacement data of a body in a rectilinear horizontal glide. The accuracy of the method was indicated by a relative standard error of calculation of less than 2.5%. Also the method was able to distinguish between subjects in their glide efficiency. It was found that the glide factor increased with decreasing velocity. The glide coefficient also increased with decreasing Reynolds number. The method is sufficiently accurate to distinguish between individual swimmers in terms of their glide efficiency. The separation of glide factor to a size

  10. Gliding flight in a jackdaw: a wind tunnel study.

    PubMed

    Rosén, M; Hedenström, A

    2001-03-01

    We examined the gliding flight performance of a jackdaw Corvus monedula in a wind tunnel. The jackdaw was able to glide steadily at speeds between 6 and 11 m s(-1). The bird changed its wingspan and wing area over this speed range, and we measured the so-called glide super-polar, which is the envelope of fixed-wing glide polars over a range of forward speeds and sinking speeds. The glide super-polar was an inverted U-shape with a minimum sinking speed (V(ms)) at 7.4 m s(-1) and a speed for best glide (V(bg)) at 8.3 m s(-)). At the minimum sinking speed, the associated vertical sinking speed was 0.62 m s(-1). The relationship between the ratio of lift to drag (L:D) and airspeed showed an inverted U-shape with a maximum of 12.6 at 8.5 m s(-1). Wingspan decreased linearly with speed over the whole speed range investigated. The tail was spread extensively at low and moderate speeds; at speeds between 6 and 9 m s(-1), the tail area decreased linearly with speed, and at speeds above 9 m s(-1) the tail was fully furled. Reynolds number calculated with the mean chord as the reference length ranged from 38 000 to 76 000 over the speed range 6-11 m s(-1). Comparisons of the jackdaw flight performance were made with existing theory of gliding flight. We also re-analysed data on span ratios with respect to speed in two other bird species previously studied in wind tunnels. These data indicate that an equation for calculating the span ratio, which minimises the sum of induced and profile drag, does not predict the actual span ratios observed in these birds. We derive an alternative equation on the basis of the observed span ratios for calculating wingspan and wing area with respect to forward speed in gliding birds from information about body mass, maximum wingspan, maximum wing area and maximum coefficient of lift. These alternative equations can be used in combination with any model of gliding flight where wing area and wingspan are considered to calculate sinking rate with

  11. 21 CFR 610.30 - Test for Mycoplasma.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Test for Mycoplasma. 610.30 Section 610.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS GENERAL BIOLOGICAL PRODUCTS STANDARDS Mycoplasma § 610.30 Test for Mycoplasma. Except as provided...

  12. 9 CFR 113.408 - Avian mycoplasma antigen.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ion concentration shall be determined with a pH meter which has been standardized with a pH buffer... with five Mycoplasma gallisepticum antiserums (chicken origin); Mycoplasma Meleagridis Antigen shall be examined for cross-agglutination with five Mycoplasma gallisepticum antiserums (turkey origin) and...

  13. 9 CFR 113.408 - Avian mycoplasma antigen.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ion concentration shall be determined with a pH meter which has been standardized with a pH buffer... with five Mycoplasma gallisepticum antiserums (chicken origin); Mycoplasma Meleagridis Antigen shall be examined for cross-agglutination with five Mycoplasma gallisepticum antiserums (turkey origin) and...

  14. GLobal Integrated Design Environment (GLIDE): A Concurrent Engineering Application

    NASA Technical Reports Server (NTRS)

    McGuire, Melissa L.; Kunkel, Matthew R.; Smith, David A.

    2010-01-01

    The GLobal Integrated Design Environment (GLIDE) is a client-server software application purpose-built to mitigate issues associated with real time data sharing in concurrent engineering environments and to facilitate discipline-to-discipline interaction between multiple engineers and researchers. GLIDE is implemented in multiple programming languages utilizing standardized web protocols to enable secure parameter data sharing between engineers and researchers across the Internet in closed and/or widely distributed working environments. A well defined, HyperText Transfer Protocol (HTTP) based Application Programming Interface (API) to the GLIDE client/server environment enables users to interact with GLIDE, and each other, within common and familiar tools. One such common tool, Microsoft Excel (Microsoft Corporation), paired with its add-in API for GLIDE, is discussed in this paper. The top-level examples given demonstrate how this interface improves the efficiency of the design process of a concurrent engineering study while reducing potential errors associated with manually sharing information between study participants.

  15. Draft Genome Sequence of “Candidatus Mycoplasma haemobos,” a Hemotropic Mycoplasma Identified in Cattle in Mexico

    PubMed Central

    Martínez-Ocampo, Fernando; Rodríguez-Camarillo, Sergio D.; Amaro-Estrada, Itzel

    2016-01-01

    We present here the draft genome sequence of the first “Candidatus Mycoplasma haemobos” strain found in cattle in Mexico. This hemotropic mycoplasma causes acute and chronic disease in animals. This genome is a starting point for studying the role of this mycoplasma in coinfections and synergistic mechanisms associated with the disease. PMID:27389272

  16. A gliding lizard from the Early Cretaceous of China.

    PubMed

    Li, Pi-Peng; Gao, Ke-Qin; Hou, Lian-Hai; Xu, Xing

    2007-03-27

    Gliding is an energetically efficient mode of locomotion that has evolved independently, and in different ways, in several tetrapod groups. Here, we report on an acrodontan lizard from the Early Cretaceous Jehol Group of China showing an array of morphological traits associated with gliding. It represents the only known occurrence of this specialization in a fossil lizard and provides evidence of an Early Cretaceous ecological diversification into an aerial niche by crown-group squamates. The lizard has a dorsal-rib-supported patagium, a structure independently evolved in the Late Triassic basal lepidosauromorph kuehneosaurs and the extant agamid lizard Draco, revealing a surprising case of convergent evolution among lepidosauromorphans. A patagial character combination of much longer bilaterally than anteroposteriorly, significantly thicker along the leading edge than along the trailing edge, tapered laterally to form a wing tip, and secondarily supported by an array of linear collagen fibers is not common in gliders and enriches our knowledge of gliding adaptations among tetrapods.

  17. Genes Found Essential in Other Mycoplasmas Are Dispensable in Mycoplasma bovis

    PubMed Central

    Sharma, Shukriti; Markham, Philip F.; Browning, Glenn F.

    2014-01-01

    Mycoplasmas are regarded to be useful models for studying the minimum genetic complement required for independent survival of an organism. Mycoplasma bovis is a globally distributed pathogen causing pneumonia, mastitis, arthritis, otitis media and reproductive tract disease, and genome sequences of three strains, the type strain PG45 and two strains isolated in China, have been published. In this study, several Tn4001 based transposon constructs were generated and used to create a M. bovis PG45 insertional mutant library. Direct genome sequencing of 319 independent insertions detected disruptions in 129 genes in M. bovis, 48 of which had homologues in Mycoplasma mycoides subspecies mycoides SC and 99 of which had homologues in Mycoplasma agalactiae. Sixteen genes found to be essential in previous studies on other mycoplasma species were found to be dispensable. Five of these genes have previously been predicted to be part of the core set of 153 essential genes in mycoplasmas. Thus this study has extended the list of non-essential genes of mycoplasmas from that previously generated by studies in other species. PMID:24897538

  18. Eosinophilic Fasciitis Associated with Mycoplasma arginini Infection

    PubMed Central

    Silló, Pálma; Pintér, Dóra; Ostorházi, Eszter; Mazán, Mercedes; Wikonkál, Norbert; Pónyai, Katinka; Volokhov, Dmitriy V.; Chizhikov, Vladimir E.; Szathmary, Susan; Stipkovits, Laszlo

    2012-01-01

    Eosinophilic fasciitis (EF) with generalized sclerodermiform skin lesions developed over a 19-month period in a previously healthy 23-year-old man. Although we confirmed EF by skin histology and laboratory tests, the recurrent fevers and the clinical observation of sclerotic prepuce with urethritis indicated further bacteriological analysis by conventional microbiological and DNA-based tests. Urethra cultures were positive for an arginine-hydrolyzing mycoplasma and Ureaplasma urealyticum. The patient also had serum IgM antibodies to Mycoplasma pneumoniae using enzyme-linked immunosorbent assay (ELISA)-based qualitative detection. Mycoplasma arginini was isolated from two independent venous blood serum samples and was identified by conventional microbiological tests and sequencing of the 16S rRNA and rpoB genes (GenBank sequence accession numbers HM179555 and HM179556, respectively). M. arginini genomic DNA also was detected by species-specific PCR in the skin lesion biopsy sample. Treatment with corticosteroids and long-term courses of selected antibiotics led to remission of skin symptoms and normalization of laboratory values. This report provides the first evidence of EF associated with mycoplasma infection and the second report of human infection with M. arginini and therefore suggests that this mycoplasma infection might have contributed to the pathogenesis of the disease. PMID:22189109

  19. Mycoplasma mastitis: causes, transmission, and control.

    PubMed

    Fox, Lawrence K

    2012-07-01

    Mycoplasma mastitis is an emerging mastitis pathogen. Herd prevalence has increased over the past decade, and this increase parallels the increase in average dairy herd size. It has been documented that the importation of cattle into a herd can result in new cases of Mycoplasma disease in general and Mycoplasma mastitis specifically. Thus, expanding herds are likely to have a greater incidence of this disease. Transmission of the agent can result from either contact with diseased animals or with colonized or asymptomatically infected cattle. Initial transmission might occur via nose-to-nose contact and result in an outbreak of Mycoplasma mastitis, or it might occur during the milking time. This would suggest that new, incoming animals should be quarantined before being comingled with original herd animals. Quarantining does not seem to be a biosecurity strategy often practiced in control of Mycoplasma mastitis and may not be warranted in herds with excellent milking time hygiene practices. The ability to monitor for the incipient stages of an outbreak, often done through bulk tank milk culturing, is recommended.

  20. A methodology for boost-glide transport technology planning

    NASA Technical Reports Server (NTRS)

    Repic, E. M.; Olson, G. A.; Milliken, R. J.

    1974-01-01

    A systematic procedure is presented by which the relative economic value of technology factors affecting design, configuration, and operation of boost-glide transport can be evaluated. Use of the methodology results in identification of first-order economic gains potentially achievable by projected advances in each of the definable, hypersonic technologies. Starting with a baseline vehicle, the formulas, procedures and forms which are integral parts of this methodology are developed. A demonstration of the methodology is presented for one specific boost-glide system.

  1. Ubiquity of quantum zero-point fluctuations in dislocation glide

    NASA Astrophysics Data System (ADS)

    Landeiro Dos Reis, Marie; Choudhury, Anshuman; Proville, Laurent

    2017-03-01

    Modeling the dislocation glide through atomic scale simulations in Al, Cu, and Ni and in solid solution alloys Al(Mg) and Cu(Ag), we show that in the course of the plastic deformation the variation of the crystal zero-point energy (ZPE) and the dislocation potential energy barriers are of opposite sign. The multiplicity of situations where we have observed the same trend allows us to conclude that quantum fluctuations, giving rise to the crystal ZPE, make easier the dislocation glide in most materials, even those constituted of atoms heavier than H and He.

  2. 14 CFR 29.71 - Helicopter angle of glide: Category B.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... glide must be determined in autorotation— (a) At the forward speed for minimum rate of descent as selected by the applicant; (b) At the forward speed for best glide angle; (c) At maximum weight; and (d) At...

  3. The descent of ant: field-measured performance of gliding ants.

    PubMed

    Munk, Yonatan; Yanoviak, Stephen P; Koehl, M A R; Dudley, Robert

    2015-05-01

    Gliding ants avoid predatory attacks and potentially mortal consequences of dislodgement from rainforest canopy substrates by directing their aerial descent towards nearby tree trunks. The ecologically relevant measure of performance for gliding ants is the ratio of net horizontal to vertical distance traveled over the course of a gliding trajectory, or glide index. To study variation in glide index, we measured three-dimensional trajectories of Cephalotes atratus ants gliding in natural rainforest habitats. We determined that righting phase duration, glide angle, and path directness all significantly influence variation in glide index. Unsuccessful landing attempts result in the ant bouncing off its target and being forced to make a second landing attempt. Our results indicate that ants are not passive gliders and that they exert active control over the aerodynamic forces they experience during their descent, despite their apparent lack of specialized control surfaces.

  4. Identification of cross-reactive antigens between Mycoplasma pulmonis and Mycoplasma arthritidis.

    PubMed Central

    Minion, F C; Brown, M B; Cassell, G H

    1984-01-01

    Serological cross-reactivity between Mycoplasma pulmonis and Mycoplasma arthritidis was investigated by enzyme-linked immunosorbent assay, immunoanalysis of electrophoretic blots, and protein A immunoprecipitation reactions. The results demonstrate that one-way cross-reactivity was present in both hyperimmunized and naturally infected rats and that the predominant cross-reactive antigens were M. pulmonis surface proteins. Distinct immunoblot patterns were demonstrated for M. pulmonis and M. arthritidis, allowing differentiation of the two species. The response to M. arthritidis antigens during natural infections differed greatly from that during hyperimmunization. Evidence suggested that nonprotein antigens were major determinants eliciting the antibody response to this mycoplasma. Images PMID:6690399

  5. Occurrence of mycoplasmas in semen samples of birds of prey.

    PubMed

    Lierz, M; Hafez, H M

    2008-10-01

    Mycoplasmas are well-known pathogens in a variety of animals. In poultry it is known that some species can be transmitted by semen and infect the uterus of females. As the prevalence of mycoplasmas in birds of prey is very high and artificial insemination is a commonly used technique for reproduction, the possibility of transmission Mycoplasma spp. by contaminated semen in birds of prey was investigated. Isolation of mycoplasmas was possible in five out of 32 (15.6%) semen samples of different bird of prey species. Two additional semen samples were positive for mycoplasma DNA using a Mycoplasma-genus-specific polymerase chain reaction. The isolation of mycoplasmas from a testicular sample indicates the testis as the possible source of contamination. Sequencing of large parts (>90%) of the 16S rRNA gene of the isolated mycoplasmas suggests that all isolates belong to the same species. Alignment of the sequenced products with the 16S rRNA gene of Mycoplasma species in GenBank demonstrated a similarity of 97% to Mycoplasma verecundum, but serological testing by immunobinding assay failed to identify it as such. It is recommended that the semen of donor birds of prey is examined for mycoplasmas before its use in artificial insemination.

  6. Time lapse photography as an approach to understanding glide avalanche activity

    USGS Publications Warehouse

    Hendrikx, Jordy; Peitzsch, Erich H.; Fagre, Daniel B.

    2012-01-01

    Avalanches resulting from glide cracks are notoriously difficult to forecast, but are a recurring problem for numerous avalanche forecasting programs. In some cases glide cracks are observed to open and then melt away in situ. In other cases, they open and then fail catastrophically as large, full-depth avalanches. Our understanding and management of these phenomena are currently limited. It is thought that an increase in the rate of snow gliding occurs prior to full-depth avalanche activity so frequent observation of glide crack movement can provide an index of instability. During spring 2011 in Glacier National Park, Montana, USA, we began an approach to track glide crack avalanche activity using a time-lapse camera focused on a southwest facing glide crack. This crack melted in-situ without failing as a glide avalanche, while other nearby glide cracks on north through southeast aspects failed. In spring 2012, a camera was aimed at a large and productive glide crack adjacent to the Going to the Sun Road. We captured three unique glide events in the field of view. Unfortunately, all of them either failed very quickly, or during periods of obscured view, so measurements of glide rate could not be obtained. However, we compared the hourly meteorological variables during the period of glide activity to the same variables prior to glide activity. The variables air temperature, relative humidity, air pressure, incoming and reflected long wave radiation, SWE, total precipitation, and snow depth were found to be statistically different for our cases examined. We propose that these are some of the potential precursors for glide avalanche activity, but do urge caution in their use, due to the simple approach and small data set size. It is hoped that by introducing a workable method to easily record glide crack movement, combined with ongoing analysis of the associated meteorological data, we will improve our understanding of when, or if, glide avalanche activity will ensue.

  7. The occurrence of mycoplasmas in selected wild North American waterfowl

    USGS Publications Warehouse

    Goldberg, D.R.; Samuel, M.D.; Thomas, C.B.; Sharp, P.; Krapu, G.L.; Robb, J.R.

    1995-01-01

    We determined the prevalence of mycoplasma infection in breeding mallard (Anas platyrhynchos) and canvasback (Aythya valisineria) hens and their broods from the central United States (1988 to 1990); and wintering American black duck (Anas rubripes) and mallard hens from the eastern United States (1990 to 1993). Mycoplasmas were isolated by culturing tracheal swabs from 656 live birds and tissue samples from 112 dead waterfowl. Nine (18%) of 51 mycoplasma isolates were identified as Mycoplasma anatis; M. anatis was recovered from four mallards, a black duck, and a gadwall (Anas strepera) duckling. Nineteen (37%) of 51 mycoplasma isolates were identified as Mycoplasma cloacale; these isolates were obtained from mallard, canvasback, and black duck adults, and from a mallard duckling. Additional unspeciated mycoplasmas were isolated from mallards, black ducks, and one canvasback.

  8. Pulse-field electrophoresis indicates full-length Mycoplasma chromosomes range widely in size.

    PubMed Central

    Neimark, H C; Lange, C S

    1990-01-01

    Full-size linear chromosomes were prepared from mycoplasmas by using gamma-irradiation to introduce one (on average) double-strand break in their circular chromosomes. Chromosome sizes were estimated by pulsed-field gel electrophoresis (PFGE) from the mobilities of these full-length molecules relative to DNA size references. Sizes estimated for Ureaplasma urealyticum T960 and 16 Mycoplasma species ranged from 684 kbp (M. hominis) to 1315 kbp (M. iowae). Using this sample, we found no correlation between the mobility of the full-size linear chromosomes and their G + C content. Sizes for A. laidlawii and A. hippikon were within the range expected from renaturation kinetics. PFGE size estimates are in good agreement with sizes determined by other methods, including electron microscopy, an ordered clone library, and summation of restriction fragments. Our estimates also agree with those from renaturation kinetics for both the largest and some of the smallest chromosomes, but in the intermediate size range, renaturation kinetics consistently provides lower values than PFGE or electron microscopy. Our PFGE estimates show that mycoplasma chromosomes span a continual range of sizes, with several intermediate values falling between the previously recognized large and small chromosome size clusters. Images PMID:2216718

  9. RESPIRATORY PATHWAYS IN THE MYCOPLASMA I.

    PubMed Central

    Smith, S. L.; Van Demark, P. J.; Fabricant, J.

    1963-01-01

    Smith, S. L. (Cornell University, Ithaca, N.Y.), P. J. Van Demark, and J. Fabricant. Respiratory pathways in the Mycoplasma. I. Lactate oxidation by Mycoplasma gallisepticum. J. Bacteriol. 86:893–897. 1963.—Resting cells of Mycoplasma gallisepticum 293 required the addition of nicotinamide adenine dinucleotide, thiamine pyrophosphate, and flavine mononucleotide for the maximal rate of sodium lactate oxidation. Inhibitor studies, as well as spectrophotometric and chemical assays, indicate that the pathway of electron transport to oxygen during lactate oxidation does not involve heme catalysts, and is mediated by flavin-linked enzyme systems. The presence of reduced nicotinamide adenine dinucleotide-specific lactic dehydrogenase, menadione reductase, ferricyanide reductase, and reduced nicotinamide adenine dinucleotide oxidase activities was detected in cell-free extracts. No cytochrome c reductase or reduced nicotinamide adenine dinucleotide peroxidase activity was detected in these extracts. PMID:14080798

  10. Dialysis Culture of T-Strain Mycoplasmas

    PubMed Central

    Masover, Gerald K.; Hayflick, Leonard

    1974-01-01

    Using dialyzing cultures of T-strain mycoplasmas, it was possible to make some observations relevant to the growth and metabolism of these organisms which would not be possible in nondialyzing cultures due to growth inhibition of the organisms by elevated pH and increased ammonium ion concentration in media containing urea. The rate of ammonia accumulation was found to be related to the initial urea concentration in the medium and could not be accounted for by any change in the multiplication rate of the organisms. More ammonia was generated than could be accounted for by the added urea alone, suggesting that an ammonia-producing activity other than urease may be present in T-strain mycoplasmas. Titers above 107 color change units per ml were achieved in dialysis cultures of a T-strain mycoplasma in the presence of urea, and such titers were maintained for approximately 60 h during dialysis culture in the absence of added urea. PMID:4595203

  11. EXPERIMENTAL INFECTION WITH MYCOPLASMA PNEUMONIAE (EATON'S AGENT)

    PubMed Central

    Dajani, Adnan S.; Clyde, Wallace A.; Denny, Floyd W.

    1965-01-01

    The pathogenesis of Mycoplasma pneumoniae infection was studied in the Syrian hamster with qualitative and quantitative culture methods and special histopathologic techniques. The animals were readily infected with the mycoplasma, which multiplied throughout the respiratory tract. Sensitivity of this experimental host to infection was indicated by the 50 per cent infective dose, which was 10 colony-forming units of the organism. Inoculation consistently resulted in the production of peribronchial pneumonitis which was induced by the mycoplasma. The organisms were visualized in a superficial location in the mucosa of involved bronchi, by means of indirect fluorescent antibody staining and by a modification of the Brown and Brenn technique. The data indicate applicability of the hamster to the study of problems concerned with M. pneumoniae disease which are impractical or impossible to resolve in the human host. PMID:14319403

  12. Insights into the pathogenesis of Mycoplasma pneumoniae

    PubMed Central

    He, Jun; Liu, Mihua; Ye, Zhufeng; Tan, Tianping; Liu, Xinghui; You, Xiaoxing; Zeng, Yanhua; Wu, Yimou

    2016-01-01

    Mycoplasma are the smallest prokaryotic microbes present in nature. These wall-less, malleable organisms can pass through cell filters, and grow and propagate under cell-free conditions in vitro. Of the pathogenic Mycoplasma Mycoplasma pneumoniae has been examined the most. In addition to primary atypical pneumonia and community-acquired pneumonia with predominantly respiratory symptoms, M. pneumoniae can also induce autoimmune hemolytic anemia and other diseases in the blood, cardiovascular system, gastrointestinal tract and skin, and can induce pericarditis, myocarditis, nephritis and meningitis. The pathogenesis of M. pneumoniae infection is complex and remains to be fully elucidated. The present review aimed to summarize several direct damage mechanisms, including adhesion damage, destruction of membrane fusion, nutrition depletion, invasive damage, toxic damage, inflammatory damage and immune damage. Further investigations are required for determining the detailed pathogenesis of M. pneumoniae. PMID:27667580

  13. Illusory Continuity without Sufficient Sound Energy to Fill a Temporal Gap: Examples of Crossing Glide Tones

    ERIC Educational Resources Information Center

    Kuroda, Tsuyoshi; Nakajima, Yoshitaka; Eguchi, Shuntarou

    2012-01-01

    The gap transfer illusion is an auditory illusion where a temporal gap inserted in a longer glide tone is perceived as if it were in a crossing shorter glide tone. Psychophysical and phenomenological experiments were conducted to examine the effects of sound-pressure-level (SPL) differences between crossing glides on the occurrence of the gap…

  14. 14 CFR 121.360 - Ground proximity warning-glide slope deviation alerting system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ground proximity warning-glide slope... Equipment Requirements § 121.360 Ground proximity warning-glide slope deviation alerting system. (a) No... turbine-powered airplane unless it is equipped with a ground proximity warning/glide slope...

  15. Illusory Continuity without Sufficient Sound Energy to Fill a Temporal Gap: Examples of Crossing Glide Tones

    ERIC Educational Resources Information Center

    Kuroda, Tsuyoshi; Nakajima, Yoshitaka; Eguchi, Shuntarou

    2012-01-01

    The gap transfer illusion is an auditory illusion where a temporal gap inserted in a longer glide tone is perceived as if it were in a crossing shorter glide tone. Psychophysical and phenomenological experiments were conducted to examine the effects of sound-pressure-level (SPL) differences between crossing glides on the occurrence of the gap…

  16. Sialidase Activity in Mycoplasma synoviae

    PubMed Central

    May, Meghan; Kleven, Stanley H.; Brown, Daniel R.

    2008-01-01

    SUMMARY Eleven strains of the avian pathogen Mycoplasma synoviae were evaluated for the presence of sialidase activity by using the fluorogenic substrate 2′-(4-methylumbelliferyl)-α-D-N-acetylneuraminic acid and the sialidase inhibitor 2-deoxy-2,3-didehydro-N-acetylneuraminic acid. The kinetics of in vitro growth in modified Frey’s medium were also assessed for each strain. Five strains had been isolated from clinically symptomatic chickens, and strains WVU1853T and K3344 have been demonstrated to be capable of reproducing disease in specific pathogen-free chickens. All strains exhibited sialidase activity, although the amount varied 65 fold (P < 0.0001) from 1.3 x 10−7 to 2.0 x 10−9 activity units/colony-forming unit among strains. Strains originally isolated from clinically symptomatic birds had more (P < 0.05) sialidase activity than strains from asymptomatic birds. Strain WVU1853T exhibited the most sialidase activity (P < 0.0001) and grew to the highest culture density (P < 0.0001) among strains, but across strains the rank correlation of growth rate with sialidase activity was not significant. Negligible activity was detected in conditioned culture supernatant fluid. This is the first report of sialidase activity in pathogenic strains of M. synoviae, which suggests a potential enzymatic basis for virulence of the organism. PMID:18251389

  17. Mycoplasma feriruminatoris sp. nov., a fast growing Mycoplasma species isolated from wild Caprinae.

    PubMed

    Jores, Joerg; Fischer, Anne; Sirand-Pugnet, Pascal; Thomann, Andreas; Liebler-Tenorio, Elisabeth M; Schnee, Christiane; Santana-Cruz, Ivette; Heller, Martin; Frey, Joachim

    2013-12-01

    Five Mycoplasma strains from wild Caprinae were analyzed: four from Alpine ibex (Capra ibex) which died at the Berlin Zoo between 1993 and 1994, one from a Rocky Mountain goat collected in the USA prior to 1987. These five strains represented a population different from the populations belonging to the 'Mycoplasma mycoides cluster' as tested using multi locus sequence typing, Matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis and DNA-DNA hybridization. Analysis of the 16S rRNA gene (rrs), genomic sequence based in silico as well as laboratory DNA-DNA hybridization, and the analysis of phenotypic traits in particular their exceptionally rapid growth all confirmed that they do not belong to any Mycoplasma species described to date. We therefore suggest these strains represent a novel species, for which we propose the name Mycoplasma feriruminatoris sp. nov. The type strain is G5847(T) (=DSM 26019(T)=NCTC 13622(T)) [corrected].

  18. Candidatus Mycoplasma haematoparvum and Mycoplasma haemocanis infections in dogs from the United States.

    PubMed

    Compton, S M; Maggi, R G; Breitschwerdt, E B

    2012-12-01

    Mycoplasma haemocanis (Mhc) and Candidatus Mycoplasma haematoparvum (CMhp) have been described in dogs. Historically, microscopic visualization of hemotropic Mycoplasma spp. has occurred most often in immunocompromised or splenectomized dogs. The aim of this study was to determine the Mhc and CMhp prevalences among dogs from the United States. Novel 16S rRNA and RNAseP gene PCR assays were used to amplify hemotropic Mycoplasma species DNA for GenBank sequence alignment. Among the study population, hemoplasma prevalence was 1.3% (7 out of 506), with Mhc and CMhp prevalences of 0.6% and 0.8%, respectively. Two of six CMhp-infected dogs were co-infected with a Bartonella sp., and a third dog was seroreactive to Bartonella henselae antigens. The prevalence of Mhc and CMhp in this study was low; potential blood donors should be screened; and dogs and people can be co-infected with hemoplasma and Bartonella spp.

  19. 14 CFR 171.267 - Glide path automatic monitor system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Glide path automatic monitor system. 171.267 Section 171.267 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Interim Standard Microwave...

  20. Gliding swifts attain laminar flow over rough wings.

    PubMed

    Lentink, David; de Kat, Roeland

    2014-01-01

    Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1-2% of chord length on the upper surface--10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the wing surface and minimize drag for extended glides. To understand why the swift does not rely on smooth wings, we used a stethoscope to map laminar flow over preserved wings in a low-turbulence wind tunnel. By combining laminar area, lift, and drag measurements, we show that average area of laminar flow on swift wings is 69% (n = 3; std 13%) of their total area during glides that maximize flight distance and duration--similar to high-performance sailplanes. Our aerodynamic analysis indicates that swifts attain laminar flow over their rough wings because their wing size is comparable to the distance the air travels (after a roughness-induced perturbation) before it transitions from laminar to turbulent. To interpret the function of swift wing roughness, we simulated its effect on smooth model wings using physical models. This manipulation shows that laminar flow is reduced and drag increased at high speeds. At the speeds at which swifts cruise, however, swift-like roughness prolongs laminar flow and reduces drag. This feature gives small birds with rudimentary wings an edge during the evolution of glide performance.

  1. Reprint of: Dynamics of discrete screw dislocations on glide directions

    NASA Astrophysics Data System (ADS)

    Alicandro, R.; De Luca, L.; Garroni, A.; Ponsiglione, M.

    2016-12-01

    We consider a simple discrete model for screw dislocations in crystals. Using a variational discrete scheme we study the motion of a configuration of dislocations toward low energy configurations. We deduce an effective fully overdamped dynamics that follows the maximal dissipation criterion introduced in Cermelli and Gurtin (1999) and predicts motion along the glide directions of the crystal.

  2. Kick, Glide, Pole! Cross-Country Skiing Fun (Part II)

    ERIC Educational Resources Information Center

    Duoos, Bridget A.

    2012-01-01

    Part I of Kick, Glide, Pole! Cross-Country Skiing Fun, which was published in last issue, discussed how to select cross-country ski equipment, dress for the activity and the biomechanics of the diagonal stride. Part II focuses on teaching the diagonal stride technique and begins with a progression of indoor activities. Incorporating this fun,…

  3. Gliding Swifts Attain Laminar Flow over Rough Wings

    PubMed Central

    Lentink, David; de Kat, Roeland

    2014-01-01

    Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1–2% of chord length on the upper surface—10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the wing surface and minimize drag for extended glides. To understand why the swift does not rely on smooth wings, we used a stethoscope to map laminar flow over preserved wings in a low-turbulence wind tunnel. By combining laminar area, lift, and drag measurements, we show that average area of laminar flow on swift wings is 69% (n = 3; std 13%) of their total area during glides that maximize flight distance and duration—similar to high-performance sailplanes. Our aerodynamic analysis indicates that swifts attain laminar flow over their rough wings because their wing size is comparable to the distance the air travels (after a roughness-induced perturbation) before it transitions from laminar to turbulent. To interpret the function of swift wing roughness, we simulated its effect on smooth model wings using physical models. This manipulation shows that laminar flow is reduced and drag increased at high speeds. At the speeds at which swifts cruise, however, swift-like roughness prolongs laminar flow and reduces drag. This feature gives small birds with rudimentary wings an edge during the evolution of glide performance. PMID:24964089

  4. The environment and materials for glide reentry vehicles

    NASA Technical Reports Server (NTRS)

    Deutsch, G. C.

    1973-01-01

    The environmental conditions to which a large glide reentry vehicle such as the space shuttle is subjected is discussed. A comparison is made with the state of the art for materials and structures to meet this environmental threat. The options that are available are stressed as are the areas where additional research and development is required.

  5. Dynamics of discrete screw dislocations on glide directions

    NASA Astrophysics Data System (ADS)

    Alicandro, R.; De Luca, L.; Garroni, A.; Ponsiglione, M.

    2016-07-01

    We consider a simple discrete model for screw dislocations in crystals. Using a variational discrete scheme we study the motion of a configuration of dislocations toward low energy configurations. We deduce an effective fully overdamped dynamics that follows the maximal dissipation criterion introduced in Cermelli and Gurtin (1999) and predicts motion along the glide directions of the crystal.

  6. Kick, Glide, Pole! Cross-Country Skiing Fun (Part II)

    ERIC Educational Resources Information Center

    Duoos, Bridget A.

    2012-01-01

    Part I of Kick, Glide, Pole! Cross-Country Skiing Fun, which was published in last issue, discussed how to select cross-country ski equipment, dress for the activity and the biomechanics of the diagonal stride. Part II focuses on teaching the diagonal stride technique and begins with a progression of indoor activities. Incorporating this fun,…

  7. Demonstration of neuraminidase activity in Mycoplasma neurolyticum and of neuraminidase proteins in three canine Mycoplasma species.

    PubMed

    Berčič, Rebeka Lucijana; Cizelj, Ivanka; Benčina, Mateja; Narat, Mojca; Bradbury, Janet M; Dovč, Peter; Benčina, Dušan

    2012-03-23

    Neuraminidases are virulence factors in many pathogenic microorganisms. They are present also in some Mycoplasma species that cause disease in birds, dogs and alligators. Thirty-seven Mycoplasma species have been examined previously for neuraminidase (sialidase) activity, whereas many of the species causing disease in man, ruminants, pigs, rodents and other animals have not. In this study neuraminidase enzymatic activity (NEAC) was examined in 45 previously untested Mycoplasma species, including those causing diseases in man, farm animals and laboratory animals. The only species in which NEAC was found was Mycoplasma neurolyticum, specifically, its type strain (Type A(T)) which is capable of inducing neurologic signs in inoculated young mice and rats. The NEAC of washed cells was relatively weak, but it differed even more than 10-fold among cells of cultures derived from individual colonies of M. neurolyticum. A weak NEAC was also detected in the supernatant of the M. neurolyticum broth culture. Canine Mycoplasma spp. with high sialidase activity reported previously, Mycoplasma canis, Mycoplasma cynos and Mycoplasma molare had 100-fold more NEAC than M. neurolyticum, but apparent differences in NEAC levels existed among strains of M. canis and of M. cynos. Zymograms using neuraminidase-specific chromogenic substrate were used to show proteins having NEAC. In M. canis (a field isolate Larissa and the type strain PG14(T)), M. cynos (isolate 896) and M. molare (type strain H542(T)) proteins with NEAC had molecular masses of ∼130kDa, 105kDa and 110kDa, respectively. Identification of these neuraminidases could provide the basis for their molecular characterization.

  8. Conditions for growing Mycoplasma canadense and Mycoplasma verecundum in a serum-free medium.

    PubMed

    Muñoz, G; Sotomayor, P

    1990-07-01

    Mycoplasma canadense and Mycoplasma verecundum were cultured in a serum-free medium containing bovine serum albumin, cholesterol, oleic acid, and palmitic acid in order to avoid the addition of horse serum. Growth was detected by measurement of A640 and by colony formation. The level of growth attained in this medium was less than that obtained in the horse serum-supplemented media, but colonies retained their distinctive morphology.

  9. Conditions for growing Mycoplasma canadense and Mycoplasma verecundum in a serum-free medium.

    PubMed Central

    Muñoz, G; Sotomayor, P

    1990-01-01

    Mycoplasma canadense and Mycoplasma verecundum were cultured in a serum-free medium containing bovine serum albumin, cholesterol, oleic acid, and palmitic acid in order to avoid the addition of horse serum. Growth was detected by measurement of A640 and by colony formation. The level of growth attained in this medium was less than that obtained in the horse serum-supplemented media, but colonies retained their distinctive morphology. Images PMID:2202260

  10. Identification of two pathogenic avian mycoplasmas as strains of Mycoplasma pullorum.

    PubMed

    Moalic, P Y; Kempf, I; Gesbert, F; Laigret, F

    1997-01-01

    Two mycoplasma strains were isolated from dead turkey embryos. Growth properties, biochemical and serological characteristics, and protein profiles indicated that these strains were closely related to Mycoplasma pullorum CKKT (T = type strain). This was confirmed by 16S rRNA sequence analysis, and the phylogenetic position of M. pullorum was established. Pathogenicity studies showed that the two strains, as well as M. pullorum CKKT, induced a statistically significant level of mortality after inoculation into chicken embryos.

  11. The enigma of eugregarine epicytic folds: where gliding motility originates?

    PubMed Central

    2013-01-01

    Background In the past decades, many studies focused on the cell motility of apicomplexan invasive stages as they represent a potential target for chemotherapeutic intervention. Gregarines (Conoidasida, Gregarinasina) are a heterogeneous group that parasitize invertebrates and urochordates, and are thought to be an early branching lineage of Apicomplexa. As characteristic of apicomplexan zoites, gregarines are covered by a complicated pellicle, consisting of the plasma membrane and the closely apposed inner membrane complex, which is associated with a number of cytoskeletal elements. The cell cortex of eugregarines, the epicyte, is more complicated than that of other apicomplexans, as it forms various superficial structures. Results The epicyte of the eugregarines, Gregarina cuneata, G. polymorpha and G. steini, analysed in the present study is organised in longitudinal folds covering the entire cell. In mature trophozoites and gamonts, each epicytic fold exhibits similar ectoplasmic structures and is built up from the plasma membrane, inner membrane complex, 12-nm filaments, rippled dense structures and basal lamina. In addition, rib-like myonemes and an ectoplasmic network are frequently observed. Under experimental conditions, eugregarines showed varied speeds and paths of simple linear gliding. In all three species, actin and myosin were associated with the pellicle, and this actomyosin complex appeared to be restricted to the lateral parts of the epicytic folds. Treatment of living gamonts with jasplakinolide and cytochalasin D confirmed that actin actively participates in gregarine gliding. Contributions to gliding of specific subcellular components are discussed. Conclusions Cell motility in gregarines and other apicomplexans share features in common, i.e. a three-layered pellicle, an actomyosin complex, and the polymerisation of actin during gliding. Although the general architecture and supramolecular organisation of the pellicle is not correlated with

  12. A phylogenetic analysis of the mycoplasmas: basis for their classification.

    PubMed Central

    Weisburg, W G; Tully, J G; Rose, D L; Petzel, J P; Oyaizu, H; Yang, D; Mandelco, L; Sechrest, J; Lawrence, T G; Van Etten, J

    1989-01-01

    Small-subunit rRNA sequences were determined for almost 50 species of mycoplasmas and their walled relatives, providing the basis for a phylogenetic systematic analysis of these organisms. Five groups of mycoplasmas per se were recognized (provisional names are given): the hominis group (which included species such as Mycoplasma hominis, Mycoplasma lipophilum, Mycoplasma pulmonis, and Mycoplasma neurolyticum), the pneumoniae group (which included species such as Mycoplasma pneumoniae and Mycoplasma muris), the spiroplasma group (which included species such as Mycoplasma mycoides, Spiroplasma citri, and Spiroplasma apis), the anaeroplasma group (which encompassed the anaeroplasmas and acholeplasmas), and a group known to contain only the isolated species Asteroleplasma anaerobium. In addition to these five mycoplasma groups, a sixth group of variously named gram-positive, walled organisms (which included lactobacilli, clostridia, and other organisms) was also included in the overall phylogenetic unit. In each of these six primary groups, subgroups were readily recognized and defined. Although the phylogenetic units identified by rRNA comparisons are difficult to recognize on the basis of mutually exclusive phenotypic characters alone, phenotypic justification can be given a posteriori for a number of them. PMID:2592342

  13. Chronic "Candidatus Mycoplasma turicensis" infection.

    PubMed

    Novacco, Marilisa; Boretti, Felicitas S; Wolf-Jäckel, Godelind A; Riond, Barbara; Meli, Marina L; Willi, Barbara; Lutz, Hans; Hofmann-Lehmann, Regina

    2011-04-20

    "Candidatus Mycoplasma turicensis" infects felids. The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood. The goals of the present study were to (1) induce reactivation of the infection in chronic carrier cats by attempted immunosuppression, (2) identify potential tissue sequestration using real-time TaqMan® PCR and (3) monitor the humoral immune response by DnaK enzyme-linked immunosorbent assay (ELISA). Ten specified pathogen-free cats that had ostensibly recovered from experimental "Candidatus M. turicensis" infection were used: five cats (group 1) received high dose methylprednisolone (attempted immunosuppression), while five cats served as untreated controls (group 2). Besides weekly blood samples, tissue samples were collected from bone marrow, kidney, liver and salivary glands at selected time points. The cats in group 1 had significantly lower lymphocyte counts and higher blood glucose levels after methylprednisolone administration than the controls. After methylprednisolone administration one blood and three tissue samples from cats in group 1 tested PCR-positive; before the administration, only one sample was positive. All other samples tested PCR-negative. All cats stayed seropositive; the antibody levels of the cats in group 1 showed a significant transient decrease after methylprednisolone administration. This is the first study to report the presence of "Candidatus M. turicensis" in tissues of chronically infected cats and the persistence of anti-feline hemoplasma antibodies in the absence of detectable bacteremia. Methylprednisolone administration did not lead to a significant reactivation of the infection. Our results enhance the knowledge of "Candidatus M. turicensis" infection pathogenesis and are clinically relevant to the prognosis of hemoplasma-infected cats.

  14. Cellular Microbiology of Mycoplasma canis

    PubMed Central

    Michaels, Dina L.; Leibowitz, Jeffrey A.; Azaiza, Mohammed T.; Shil, Pollob K.; Shama, Suzanne M.; Kutish, Gerald F.; Distelhorst, Steven L.; Balish, Mitchell F.; May, Meghan A.

    2016-01-01

    Mycoplasma canis can infect many mammalian hosts but is best known as a commensal or opportunistic pathogen of dogs. The unexpected presence of M. canis in brains of dogs with idiopathic meningoencephalitis prompted new in vitro studies to help fill the void of basic knowledge about the organism's candidate virulence factors, the host responses that it elicits, and its potential roles in pathogenesis. Secretion of reactive oxygen species and sialidase varied quantitatively (P < 0.01) among strains of M. canis isolated from canine brain tissue or mucosal surfaces. All strains colonized the surface of canine MDCK epithelial and DH82 histiocyte cells and murine C8-D1A astrocytes. Transit through MDCK and DH82 cells was demonstrated by gentamicin protection assays and three-dimensional immunofluorescence imaging. Strains further varied (P < 0.01) in the extents to which they influenced the secretion of tumor necrosis factor alpha (TNF-α) and the neuroendocrine regulatory peptide endothelin-1 by DH82 cells. Inoculation with M. canis also decreased major histocompatibility complex class II (MHC-II) antigen expression by DH82 cells (P < 0.01), while secretion of gamma interferon (IFN-γ), interleukin-6 (IL-6), interleukin-10 (IL-10), and complement factor H was unaffected. The basis for differences in the responses elicited by these strains was not obvious in their genome sequences. No acute cytopathic effects on any homogeneous cell line, or consistent patterns of M. canis polyvalent antigen distribution in canine meningoencephalitis case brain tissues, were apparent. Thus, while it is not likely a primary neuropathogen, M. canis has the capacity to influence meningoencephalitis through complex interactions within the multicellular and neurochemical in vivo milieu. PMID:27045036

  15. A Compendium for Mycoplasma pneumoniae

    PubMed Central

    Parrott, Gretchen L.; Kinjo, Takeshi; Fujita, Jiro

    2016-01-01

    Historically, atypical pneumonia was a term used to describe an unusual presentation of pneumonia. Currently, it is used to describe the multitude of symptoms juxtaposing the classic symptoms found in cases of pneumococcal pneumonia. Specifically, atypical pneumonia is a syndrome resulting from a relatively common group of pathogens including Chlamydophila sp., and Mycoplasma pneumoniae. The incidence of M. pneumoniae pneumonia in adults is less than the burden experienced by children. Transmission rates among families indicate children may act as a reservoir and maintain contagiousness over a long period of time ranging from months to years. In adults, M. pneumoniae typically produces a mild, “walking” pneumonia and is considered to be one of the causes of persistent cough in patients. M. pneumoniae has also been shown to trigger the exacerbation of other lung diseases. It has been repeatedly detected in patients with bronchitis, asthma, chronic obstructive pulmonary disorder, and cystic fibrosis. Recent advances in technology allow for the rapid diagnosis of M. pneumoniae through the use of polymerase chain reaction or rapid antigen tests. With this, more effort has been afforded to identify the causative etiologic agent in all cases of pneumonia. However, previous practices, including the overprescribing of macrolide treatment in China and Japan, have created increased incidence of macrolide-resistant M. pneumoniae. Reports from these countries indicate that >85% of M. pneumoniae pneumonia pediatric cases are macrolide-resistant. Despite its extensively studied past, the smallest bacterial species still inspires some of the largest questions. The developments in microbiology, diagnostic features and techniques, epidemiology, treatment and vaccines, and upper respiratory conditions associated with M. pneumoniae in adult populations are included within this review. PMID:27148202

  16. A Compendium for Mycoplasma pneumoniae.

    PubMed

    Parrott, Gretchen L; Kinjo, Takeshi; Fujita, Jiro

    2016-01-01

    Historically, atypical pneumonia was a term used to describe an unusual presentation of pneumonia. Currently, it is used to describe the multitude of symptoms juxtaposing the classic symptoms found in cases of pneumococcal pneumonia. Specifically, atypical pneumonia is a syndrome resulting from a relatively common group of pathogens including Chlamydophila sp., and Mycoplasma pneumoniae. The incidence of M. pneumoniae pneumonia in adults is less than the burden experienced by children. Transmission rates among families indicate children may act as a reservoir and maintain contagiousness over a long period of time ranging from months to years. In adults, M. pneumoniae typically produces a mild, "walking" pneumonia and is considered to be one of the causes of persistent cough in patients. M. pneumoniae has also been shown to trigger the exacerbation of other lung diseases. It has been repeatedly detected in patients with bronchitis, asthma, chronic obstructive pulmonary disorder, and cystic fibrosis. Recent advances in technology allow for the rapid diagnosis of M. pneumoniae through the use of polymerase chain reaction or rapid antigen tests. With this, more effort has been afforded to identify the causative etiologic agent in all cases of pneumonia. However, previous practices, including the overprescribing of macrolide treatment in China and Japan, have created increased incidence of macrolide-resistant M. pneumoniae. Reports from these countries indicate that >85% of M. pneumoniae pneumonia pediatric cases are macrolide-resistant. Despite its extensively studied past, the smallest bacterial species still inspires some of the largest questions. The developments in microbiology, diagnostic features and techniques, epidemiology, treatment and vaccines, and upper respiratory conditions associated with M. pneumoniae in adult populations are included within this review.

  17. Mycoplasma genitalium: An emergent sexually transmitted disease?

    PubMed

    Manhart, Lisa E

    2013-12-01

    This article summarizes the epidemiologic evidence linking Mycoplasma genitalium to sexually transmitted disease syndromes, including male urethritis, and female cervicitis, pelvic inflammatory disease, infertility, and adverse birth outcomes. It discusses the relationship of this bacterium to human immunodeficiency virus infection and reviews the available literature on the efficacy of standard antimicrobial therapies against M genitalium.

  18. Mycoplasma gallisepticum: Control by live attenuated vaccines

    USDA-ARS?s Scientific Manuscript database

    Commercially available attenuated strains of Mycoplasma gallisepticum (MG) are commonly used within the layer industry to control MG-induced mycoplasmosis. Among these are two live MG vaccines derived from the moderately pathogenic MG “chick F” strain. In the present study, the commercially availa...

  19. Mycoplasma Pneumoniae Infections of Adults and Children

    PubMed Central

    Cherry, James D.; Welliver, Robert C.

    1976-01-01

    Although the hallmark of Mycoplasma pneumoniae infection is pneumonia, the organism is also responsible for a protean array of other symptoms. With an increased awareness of the board clinical spectrum of M. pneumoniae disease and the ready availability of the cold agglutinin and M. pneumoniae complement-fixation tests, interested clinicians will note additional clinical-mycoplasmal associations in their patients. PMID:782043

  20. Mycoplasma wenyonii infection in dairy cows.

    PubMed

    2016-12-17

    Mycoplasma wenyonii infection in two dairy herdsHypomagnesaemia in suckler cowsLeptospiral milk drop in dairy cowsNon-resolving orf in six-month-old lambsHepatosis dietetica in a five-month-old giltThese are among matters discussed in the disease surveillance report for September 2016 from SAC Consulting: Veterinary Services (SAC C VS). British Veterinary Association.

  1. A comparison of glide force characteristics between 2 prefilled insulin lispro pens.

    PubMed

    Rees, Tina M; Lennartz, Amanda H; Ignaut, Debra A

    2015-03-01

    Glide force, average glide force, and glide force variability of the insulin lispro 200 units/mL pen (Eli Lilly and Company, Indianapolis, IN, USA) were compared to the Humalog KwikPen 100 units/mL pen (hereafter, KwikPen; Eli Lilly and Company, Indianapolis, IN, USA). Data were collected on 2 doses, 2 injection speeds, and 2 needle types. Insulin lispro 200 units/mL pen showed significantly lower maximum glide force, average glide force, and glide force variability than the KwikPen across all combinations of dose size, dose speed, and needle type. The lower glide force observed with the insulin lispro 200 units/mL pen offers another treatment option for patients with type 1 or type 2 diabetes who require greater than 20 units of mealtime insulin daily.

  2. The gliding speed of migrating birds: slow and safe or fast and risky?

    PubMed

    Horvitz, Nir; Sapir, Nir; Liechti, Felix; Avissar, Roni; Mahrer, Isaac; Nathan, Ran

    2014-06-01

    Aerodynamic theory postulates that gliding airspeed, a major flight performance component for soaring avian migrants, scales with bird size and wing morphology. We tested this prediction, and the role of gliding altitude and soaring conditions, using atmospheric simulations and radar tracks of 1346 birds from 12 species. Gliding airspeed did not scale with bird size and wing morphology, and unexpectedly converged to a narrow range. To explain this discrepancy, we propose that soaring-gliding birds adjust their gliding airspeed according to the risk of grounding or switching to costly flapping flight. Introducing the Risk Aversion Flight Index (RAFI, the ratio of actual to theoretical risk-averse gliding airspeed), we found that inter- and intraspecific variation in RAFI positively correlated with wing loading, and negatively correlated with convective thermal conditions and gliding altitude, respectively. We propose that risk-sensitive behaviour modulates the evolution (morphology) and ecology (response to environmental conditions) of bird soaring flight.

  3. Isolation and characterization of unusual Mycoplasma spp. from captive Eurasian Griffon (Gyps fulvus) in Sicily.

    PubMed

    Loria, G R; Ferrantelli, E; Giardina, G; Li Vecchi, L; Sparacino, L; Oliveri, F; McAuliffe, L; Nicholas, R A J

    2008-01-01

    Mycoplasmas have been isolated from birds of prey during clinical examinations, but their significance to the health of raptors is unclear. We report the isolation and characterization of four mycoplasmas found in the upper respiratory tract of four sick Eurasian Griffon (Gyps fulvus) that were housed in a Sicilian rehabilitation center at Ficuzza, near Palermo in Sicily, before reintroduction into the wild. These included Mycoplasma gallinarum, an unidentified mycoplasma highly similar to Mycoplasma glycophilum, and two unidentified mycoplasmas with similarities to Mycoplasma falconis and Mycoplasma gateae.

  4. Development of fluorescence expression tools to study host-mycoplasma interactions and validation in two distant mycoplasma clades.

    PubMed

    Bonnefois, Tiffany; Vernerey, Marie-Stéphanie; Rodrigues, Valérie; Totté, Philippe; Puech, Carinne; Ripoll, Chantal; Thiaucourt, François; Manso-Silván, Lucía

    2016-10-20

    Fluorescence expression tools for stable and innocuous whole mycoplasma cell labelling have been developed. A Tn4001-derivative mini-transposon affording unmarked, stable mutagenesis in mycoplasmas was modified to allow the constitutive, high-level expression of mCherry, mKO2 and mNeonGreen. These tools were used to introduce the respective fluorescent proteins as chromosomal tags in the phylogenetically distant species Mycoplasma mycoides subsp. mycoides and Mycoplasma bovis. The production, selection and characterisation of fluorescent clones were straightforward and resulted in the unprecedented observation of red and green fluorescent mycoplasma colonies in the two species, with no apparent cytotoxicity. Equivalent fluorescence expression levels were quantified by flow cytometry in both species, suggesting that these tools can be broadly applied in mycoplasmas. A macrophage infection assay was performed to assess the usefulness of mNeonGreen-expressing strains for monitoring mycoplasma infections, and notably cell invasion. The presence of fluorescent mycoplasmas inside live phagocytic cells was detected and quantified by flow cytometry and corroborated by confocal microscopy, which allowed the identification of individual mycoplasmas in the cytoplasm of infected cells. The fluorescence expression tools developed in this study are suitable for host-pathogen interaction studies and offer innumerable perspectives for the functional analysis of mycoplasmas both in vitro and in vivo.

  5. The relationship between 3-D kinematics and gliding performance in the southern flying squirrel, Glaucomys volans.

    PubMed

    Bishop, Kristin L

    2006-02-01

    Gliding is the simplest form of flight, yet relatively little is known about its mechanics in animals. The goal of this study was to describe the body position and performance of a gliding mammal and to identify correlates between kinematics and aerodynamic performance. To do this, I used a pair of high-speed digital cameras to record a portion of the middle of glides by southern flying squirrels, Glaucomys volans. The squirrels launched from a height of 4 m and landed on a vertical pole. Reflective markers were applied to anatomical landmarks and the 3-D coordinates of these points were computed to describe the kinematics of the glides. From these data I estimated the lift and drag generated during the glide, and correlated these variables with gliding performance as measured by glide angle, glide speed and stability. In the majority of the glide sequences the squirrels accelerated in the downward direction and accelerated horizontally forward as they moved through the calibrated volume in the middle of the glide trajectory, rather than exhibiting a steady glide in which the body weight is balanced by the resultant aerodynamic force. Compared to human engineered airfoils, the angles of attack used by the squirrels were unexpectedly high, ranging from 35.4 degrees to 53.5 degrees , far above the angle of attack at which an aircraft wing would typically stall. As expected based on aerodynamic theory, there was a negative correlation between angle of attack and lift coefficient, indicating that the wings are stalled, and a positive correlation between angle of attack and drag coefficient. Also as expected, there was a negative correlation between lift-to-drag ratio and angle of attack, as increasing angle of attack produced both less lift and more drag. Within glides, there was a strong correlation between nose-down pitching rotations and limb movements that tended to increase the angle of attack of the wing membrane, suggesting that the animals actively control

  6. Postoperative Mycoplasma hominis infections after neurosurgical intervention.

    PubMed

    Whitson, Wesley J; Ball, Perry A; Lollis, S Scott; Balkman, Jason D; Bauer, David F

    2014-08-01

    Mycoplasma hominis is a rare cause of infection after neurosurgical procedures. The Mycoplasma genus contains the smallest bacteria discovered to date. Mycoplasma are atypical bacteria that lack a cell wall, a feature that complicates both diagnosis and treatment. The Gram stain and some types of culture media fail to identify these organisms, and typical broad-spectrum antibiotic regimens are ineffective because they act on cell wall metabolism. Mycoplasma hominis commonly colonizes the genitourinary tract in a nonvirulent manner, but it has caused postoperative, postpartum, and posttraumatic infections in various organ systems. The authors present the case of a 17-year-old male with a postoperative intramedullary spinal cord abscess due to M. hominis and report the results of a literature review of M. hominis infections after neurosurgical procedures. Attention is given to time to diagnosis, risk factors for infection, ineffective antibiotic regimens, and final effective antibiotic regimens to provide pertinent information for the practicing neurosurgeon to diagnose and treat this rare occurrence. A PubMed search was performed to identify reports of M. hominis infections after neurosurgical procedures. Eleven cases of postneurosurgical M. hominis infection were found. No other cases of intramedullary spinal cord abscess were found. Initial antibiotic coverage was inadequate in all cases, and diagnosis was delayed in all cases. Multiple surgical interventions were often needed. Once appropriate antibiotics were started, patients typically experienced rapid resolution of their neurological symptoms. In 27% of cases, a suspicious genitourinary source other than urinary catheterization was identified. Postoperative M. hominis infections are rarely seen after neurosurgical procedures. They are typically responsive to appropriate antibiotic therapy. Mycoplasma infection may cause prolonged hospitalization and multiple returns to the operating room due to delay in

  7. Transcriptome changes in Mycoplasma hyopneumoniae during infection.

    PubMed

    Madsen, Melissa L; Puttamreddy, Supraja; Thacker, Eileen L; Carruthers, Michael D; Minion, F Chris

    2008-02-01

    Mycoplasma hyopneumoniae causes swine pneumonia and contributes significantly to the porcine respiratory disease complex. The mechanisms of pathogenesis are difficult to address, since there is a lack of genetic tools, but microarrays are available and can be used to study transcriptional changes that occur during disease as a way to identify important virulence-related genes. Mycoplasmas were collected from bronchial alveolar lavage samples and compared to broth-grown cells using microarrays. Bronchial alveolar lavage was performed on pigs 28 days postinfection, and mycoplasmas were isolated by differential centrifugation. Mycoplasma RNA-enriched preparations were then obtained from total RNA by subtracting eucaryotic ribosomal and messenger RNAs. Labeled cDNAs were generated with mycoplasma open reading frame-specific primers. Nine biological replicates were analyzed. During lung infection, our analysis indicated that 79 M. hyopneumoniae genes were differentially expressed (P < 0.01), at a false-discovery rate of <2.7%. Of the down-regulated genes, 28 of 46 (61%) lacked an assigned function, in comparison to 21 of 33 (63%) of up-regulated genes. Four down-regulated genes and two up-regulated genes encoded putative lipoproteins. secA (mhp295) (P = 0.003) and two glycerol transport permease genes (potA [mhp380; P = 0.006] and ugpA [mhp381; P = 0.003]) were up-regulated in vivo. Elongation factor EF-G (fusA [mhp083]) (P = 0.002), RNA polymerase beta chain (rpoC [mhp635]) (P = 0.003), adenylate kinase (adk [mhp208]) (P = 0.001), prolyl aminoacyl tRNA synthetase (proS [mhp397]) (P = 0.009), and cysteinyl-tRNA synthetase (cysS [mhp661]) (P < 0.001) were down-regulated in vivo.

  8. Antimicrobial susceptibilities of Mycoplasma isolated from bovine mastitis in Japan.

    PubMed

    Kawai, Kazuhiro; Higuchi, Hidetoshi; Iwano, Hidetomo; Iwakuma, Akihiro; Onda, Ken; Sato, Reiichiro; Hayashi, Tomohito; Nagahata, Hajime; Oshida, Toshio

    2014-01-01

    Mycoplasma spp. are highly contagious pathogens and intramammary Mycoplasma infection is a serious issue for the dairy industry. As there is no effective vaccine for Mycoplasma infection, control depends on good husbandry and chemo-antibiotic therapy. In this study, antimicrobial susceptibility of Mycoplasma strains recently isolated from cases of bovine mastitis in Japan was evaluated by minimum inhibitory concentration (MIC). All Mycoplasma bovis strains were sensitive to pirlimycin, danofloxacin and enrofloxacin, but not kanamycin, oxytetracycline, tilmicosin or tylosin. M. californicum and M. bovigenitalium strains were sensitive to pirlimycin, danofloxacin, enrofloxacin, oxytetracycline, tilmicosin and tylosin, but not to kanamycin. This is the first report to describe the MIC of major antimicrobial agents for Mycoplasma species isolated from bovine mastitis in Japan.

  9. Gliding motility powers invasion and egress in Apicomplexa.

    PubMed

    Frénal, Karine; Dubremetz, Jean-François; Lebrun, Maryse; Soldati-Favre, Dominique

    2017-09-04

    Protozoan parasites have developed elaborate motility systems that facilitate infection and dissemination. For example, amoebae use actin-rich membrane extensions called pseudopodia, whereas Kinetoplastida are propelled by microtubule-containing flagella. By contrast, the motile and invasive stages of the Apicomplexa - a phylum that contains the important human pathogens Plasmodium falciparum (which causes malaria) and Toxoplasma gondii (which causes toxoplasmosis) - have a unique machinery called the glideosome, which is composed of an actomyosin system that underlies the plasma membrane. The glideosome promotes substrate-dependent gliding motility, which powers migration across biological barriers, as well as active host cell entry and egress from infected cells. In this Review, we discuss the discovery of the principles that govern gliding motility, the characterization of the molecular machinery involved, and its impact on parasite invasion and egress from infected cells.

  10. Circular random motion in diatom gliding under isotropic conditions

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Medina, Braulio; Jiménez Guerra, Andrés; Peña Maldonado, Ana Iris; Covarrubias Rubio, Yadiralia; Viridiana García Meza, Jessica

    2014-12-01

    How cells migrate has been investigated primarily for the case of trajectories composed by joined straight segments. In contrast, little is known when cellular motion follows intrinsically curved paths. Here, we use time-lapse optical microscopy and automated trajectory tracking to investigate how individual cells of the diatom Nitzschia communis glide across surfaces under isotropic environmental conditions. We find a distinct kind of random motion, where trajectories are formed by circular arcs traveled at constant speed, alternated with random stoppages, direction reversals and changes in the orientation of the arcs. Analysis of experimental and computer-simulated trajectories show that the circular random motion of diatom gliding is not optimized for long-distance travel but rather for recurrent coverage of limited surface area. These results suggest that one main biological role for this type of diatom motility is to efficiently build the foundation of algal biofilms.

  11. Substrate induced gliding for a nematic liquid crystal layer

    NASA Astrophysics Data System (ADS)

    Mema, Ensela; Cummings, Linda; Kondic, Lou

    2015-03-01

    The interaction between nematic liquid crystals (NLC) and polymer substrates is of current industrial interest, due to a desire to manufacture a new generation of flexible Liquid Crystal Displays (LCDs) for use in portable electronic devices. Polymer substrates present challenges because they can interact with the NLC, exhibiting a phenomenon known as gliding: the preferred orientation of the NLC molecules at the interface changes over timescales of minutes to hours. We present two models for gliding, inspired by the physics and chemistry of the interaction between the NLC and polymer substrate. These models, though simple, lead to non-trivial results, including loss of bistability, a finding that may have implications for display devices. Supported by NSF Grant No. DMS-1211713.

  12. Investigation of Aerodynamic Capabilities of Flying Fish in Gliding Flight

    NASA Astrophysics Data System (ADS)

    Park, H.; Choi, H.

    In the present study, we experimentally investigate the aerodynamic capabilities of flying fish. We consider four different flying fish models, which are darkedged-wing flying fishes stuffed in actual gliding posture. Some morphological parameters of flying fish such as lateral dihedral angle of pectoral fins, incidence angles of pectoral and pelvic fins are considered to examine their effect on the aerodynamic performance. We directly measure the aerodynamic properties (lift, drag, and pitching moment) for different morphological parameters of flying fish models. For the present flying fish models, the maximum lift coefficient and lift-to-drag ratio are similar to those of medium-sized birds such as the vulture, nighthawk and petrel. The pectoral fins are found to enhance the lift-to-drag ratio and the longitudinal static stability of gliding flight. On the other hand, the lift coefficient and lift-to-drag ratio decrease with increasing lateral dihedral angle of pectoral fins.

  13. Gliding hexapods and the origins of insect aerial behaviour

    PubMed Central

    Yanoviak, Stephen P; Kaspari, Michael; Dudley, Robert

    2009-01-01

    Directed aerial descent (i.e. gliding and manoeuvring) may be an important stage in the evolution of winged flight. Although hypothesized to occur in ancestrally wingless insects, such behaviour is unexplored in extant basal hexapods, but has recently been described in arboreal ants. Here we show that tropical arboreal bristletails (Archaeognatha) direct their horizontal trajectories to tree trunks in approximately 90 per cent of falls. Experimental manipulation of the median caudal filament significantly reduced both success rate (per cent of individuals landing on a tree trunk) and performance (glide index) versus controls. The existence of aerial control in the ancestrally wingless bristletails, and its habitat association with an arboreal lifestyle, are consistent with the hypothesis of a terrestrial origin for winged flight in insects. PMID:19324632

  14. Coupled glide-climb diffusion-enhanced crystal plasticity

    NASA Astrophysics Data System (ADS)

    Geers, M. G. D.; Cottura, M.; Appolaire, B.; Busso, E. P.; Forest, S.; Villani, A.

    2014-10-01

    This paper presents a fully coupled glide-climb crystal plasticity model, whereby climb is controlled by the diffusion of vacancies. An extended strain gradient crystal plasticity model is therefore proposed, which incorporates the climbing of dislocations in the governing transport equations. A global-local approach is adopted to separate the scales and assess the influence of local diffusion on the global plasticity problem. The kinematics of the crystal plasticity model is enriched by incorporating the climb kinematics in the crystallographic split of the plastic strain rate tensor. The potential of the fully coupled theory is illustrated by means of two single slip examples that illustrate the interaction between glide and climb in either bypassing a precipitate or destroying a dislocation pile-up.

  15. Mimicking glide symmetry dispersion with coupled slot metasurfaces

    NASA Astrophysics Data System (ADS)

    Camacho, Miguel; Mitchell-Thomas, Rhiannon C.; Hibbins, Alastair P.; Sambles, J. Roy; Quevedo-Teruel, Oscar

    2017-09-01

    In this letter, we demonstrate that the dispersion properties associated with glide symmetry can be achieved in systems that only possess reflection symmetry by balancing the influence of two sublattices. We apply this approach to a pair of coupled slots cut into an infinite perfectly conducting plane. Each slot is notched on either edge, with the complete two-slot system having only mirror symmetry. By modifying the relative size of the notches on either side of the slots, we show that a linear dispersion relation with a degeneracy with non-zero group velocity at the Brillouin zone boundary can be achieved. These properties, until now, only found in systems with glide symmetry are numerically and experimentally validated. We also show that these results can be used for the design of ultra-wideband one-dimensional leaky wave antennas in coplanar waveguide technology.

  16. GLIDES – Efficient Energy Storage from ORNL

    ScienceCinema

    Momen, Ayyoub M.; Abu-Heiba, Ahmad; Odukomaiya, Wale; Akinina, Alla

    2016-07-12

    The research shown in this video features the GLIDES (Ground-Level Integrated Diverse Energy Storage) project, which has been under development at Oak Ridge National Laboratory (ORNL) since 2013. GLIDES can store energy via combined inputs of electricity and heat, and deliver dispatchable electricity. Supported by ORNL’s Laboratory Director’s Research and Development (LDRD) fund, this energy storage system is low-cost, and hybridizes compressed air and pumped-hydro approaches to allow for storage of intermittent renewable energy at high efficiency. A U.S. patent application for this novel energy storage concept has been submitted, and research findings suggest it has the potential to be a flexible, low-cost, scalable, high-efficiency option for energy storage, especially useful in residential and commercial buildings.

  17. [Sensorineural hearing impairment in combination with mycoplasma infection].

    PubMed

    Gurov, A V; Levina, Yu V; Rudenko, V V

    2015-01-01

    The objective of the present study was to elucidate the incidence of mycoplasma infection concomitant with sensorineural hearing impairment and its clinical manifestations with special reference to the methods for its diagnostics and treatment. The main method for the detection of mycoplasma infection is PCR in real time and the auxiliary one is the immunoenzymatic assay. The study revealed mycoplasma infection in 15 (13.9%) of the examined patients. The results of our investigations give evidence of the necessity to further study the clinical symptoms of mycoplasma infection associated with sensorineural hearing impairment and to search for the methods of the management of this condition.

  18. The biology of gliding in flying lizards (genus Draco) and their fossil and extant analogs.

    PubMed

    McGuire, Jimmy A; Dudley, Robert

    2011-12-01

    The flying lizards of the genus Draco are among the most remarkable and successful clades of gliding vertebrates. Here, we evaluate the evolution of gliding in Draco and other lizards, describe the suite of morphological innovations that characterize Draco, discuss the ecological context of gliding in this genus, describe functions of their patagial membranes that are not related to gliding, and summarize the interspecific allometry of the Draco gliding apparatus, as well as the corresponding consequences for their now empirically quantified gliding performance. Several fossil reptilian lineages had morphologies similar to that of modern Draco, with patagial membranes supported by elongated ribs or rib-like dermal structures. Using Draco's snout-vent length/mass relationships, we provide improved estimates of wing loading for three of these fossil gliders (Icarosaurus seifkeri, Kuehneosaurus sp., Coelurosauravus elivensis) and then estimate absolute gliding performance for each taxon by extrapolating from Draco's wing loading/glide performance relationship. We find that I. seifkeri likely represented the best nonflapping terrestrial vertebrate glider yet described, whereas the larger Kuehneosaurus and Coelurosauravus probably required high descent velocities to achieve sufficient lift for gliding, with commensurately greater height loss with each glide.

  19. Gliding motility and Por secretion system genes are widespread among members of the phylum bacteroidetes.

    PubMed

    McBride, Mark J; Zhu, Yongtao

    2013-01-01

    The phylum Bacteroidetes is large and diverse, with rapid gliding motility and the ability to digest macromolecules associated with many genera and species. Recently, a novel protein secretion system, the Por secretion system (PorSS), was identified in two members of the phylum, the gliding bacterium Flavobacterium johnsoniae and the nonmotile oral pathogen Porphyromonas gingivalis. The components of the PorSS are not similar in sequence to those of other well-studied bacterial secretion systems. The F. johnsoniae PorSS genes are a subset of the gliding motility genes, suggesting a role for the secretion system in motility. The F. johnsoniae PorSS is needed for assembly of the gliding motility apparatus and for secretion of a chitinase, and the P. gingivalis PorSS is involved in secretion of gingipain protease virulence factors. Comparative analysis of 37 genomes of members of the phylum Bacteroidetes revealed the widespread occurrence of gliding motility genes and PorSS genes. Genes associated with other bacterial protein secretion systems were less common. The results suggest that gliding motility is more common than previously reported. Microscopic observations confirmed that organisms previously described as nonmotile, including Croceibacter atlanticus, "Gramella forsetii," Paludibacter propionicigenes, Riemerella anatipestifer, and Robiginitalea biformata, exhibit gliding motility. Three genes (gldA, gldF, and gldG) that encode an apparent ATP-binding cassette transporter required for F. johnsoniae gliding were absent from two related gliding bacteria, suggesting that the transporter may not be central to gliding motility.

  20. Secretomes of Mycoplasma hyopneumoniae and Mycoplasma flocculare reveal differences associated to pathogenesis.

    PubMed

    Paes, Jéssica A; Lorenzatto, Karina R; de Moraes, Sofia N; Moura, Hercules; Barr, John R; Ferreira, Henrique B

    2017-02-10

    Mycoplasma hyopneumoniae and Mycoplasma flocculare cohabit the porcine respiratory tract. However, M. hyopneumoniae causes the porcine enzootic pneumonia, while M. flocculare is a commensal bacterium. Comparative analyses demonstrated high similarity between these species, which includes the sharing of all predicted virulence factors. Nevertheless, studies related to soluble secretomes of mycoplasmas were little known, although they are important for bacterial-host interactions. The aim of this study was to perform a comparative analysis between the soluble secreted proteins repertoires of the pathogenic Mycoplasma hyopneumoniae and its closely related commensal Mycoplasma flocculare. For that, bacteria were cultured in medium with reduced serum concentration and secreted proteins were identified by a LC-MS/MS proteomics approach. Altogether, 62 and 26 proteins were identified as secreted by M. hyopneumoniae and M. flocculare, respectively, being just seven proteins shared between these bacteria. In M. hyopneumoniae secretome, 15 proteins described as virulence factors were found; while four putative virulence factors were identified in M. flocculare secretome. For the first time, clear differences related to virulence were found between these species, helping to elucidate the pathogenic nature of M. hyopneumoniae to swine hosts.

  1. A gliding lizard from the Early Cretaceous of China

    PubMed Central

    Li, Pi-Peng; Gao, Ke-Qin; Hou, Lian-Hai; Xu, Xing

    2007-01-01

    Gliding is an energetically efficient mode of locomotion that has evolved independently, and in different ways, in several tetrapod groups. Here, we report on an acrodontan lizard from the Early Cretaceous Jehol Group of China showing an array of morphological traits associated with gliding. It represents the only known occurrence of this specialization in a fossil lizard and provides evidence of an Early Cretaceous ecological diversification into an aerial niche by crown-group squamates. The lizard has a dorsal-rib-supported patagium, a structure independently evolved in the Late Triassic basal lepidosauromorph kuehneosaurs and the extant agamid lizard Draco, revealing a surprising case of convergent evolution among lepidosauromorphans. A patagial character combination of much longer bilaterally than anteroposteriorly, significantly thicker along the leading edge than along the trailing edge, tapered laterally to form a wing tip, and secondarily supported by an array of linear collagen fibers is not common in gliders and enriches our knowledge of gliding adaptations among tetrapods. PMID:17376871

  2. Glide twinning and pseudotwinning in peristerite: twin morphology and propagation

    NASA Astrophysics Data System (ADS)

    Brown, William L.

    1989-07-01

    Optically visible Albite glide “twins” in a peristerite (˜An9Or1.6), identified from their tapering shape and relationship to grain boundaries, were studied by transmission electron microscopy. Near the tips in sections ⊥ a, the microstructure consists of small (˜400 nm long) lensshaped Albite twins centred exclusively on the oligoclase lamellae. The lenses extend partly outwards into the two adjacent low albite lamellae and induce strong inhomogeneous strain. Where the lenses are closer together, they form, depending on the sense of shear, nearly linear left or right-stepping en échelon arrays, with overlap of the strain fields. Slightly farther in from the tip, the twin domains coalesce to form continuous pinch-and-swell lamellae, being always thicker in the oligoclase. Because of Si,Al order, only elastic glide pseudotwins are possible in low albite. In oligoclase glide pseudotwins may be mechanically stable (metastable relative to Si,Al order) and may deviate only slightly from true twins. Pseudotwins develop first in the oligoclase, propagate dynamically by jumping across the intervening albite lamellae, extend lengthways and thicken sideways and finally coalesce. They are stabilized by diffusion-controlled inversion of Si,Al order giving rise to true twins described in a companion paper.

  3. Characteristics of Atmospheric Pressure Rotating Gliding Arc Plasmas

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Zhu, Fengsen; Tu, Xin; Bo, Zheng; Cen, Kefa; Li, Xiaodong

    2016-05-01

    In this work, a novel direct current (DC) atmospheric pressure rotating gliding arc (RGA) plasma reactor has been developed for plasma-assisted chemical reactions. The influence of the gas composition and the gas flow rate on the arc dynamic behaviour and the formation of reactive species in the N2 and air gliding arc plasmas has been investigated by means of electrical signals, high speed photography, and optical emission spectroscopic diagnostics. Compared to conventional gliding arc reactors with knife-shaped electrodes which generally require a high flow rate (e.g., 10-20 L/min) to maintain a long arc length and reasonable plasma discharge zone, in this RGA system, a lower gas flow rate (e.g., 2 L/min) can also generate a larger effective plasma reaction zone with a longer arc length for chemical reactions. Two different motion patterns can be clearly observed in the N2 and air RGA plasmas. The time-resolved arc voltage signals show that three different arc dynamic modes, the arc restrike mode, takeover mode, and combined modes, can be clearly identified in the RGA plasmas. The occurrence of different motion and arc dynamic modes is strongly dependent on the composition of the working gas and gas flow rate. supported by National Natural Science Foundation of China (No. 51576174), the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20120101110099) and the Fundamental Research Funds for the Central Universities (No. 2015FZA4011)

  4. Development of the Gliding Hole of the Dynamics Compression Plate

    NASA Astrophysics Data System (ADS)

    Salim, U. A.; Suyitno; Magetsari, R.; Mahardika, M.

    2017-02-01

    The gliding hole of the dynamics compression plate is designed to facilitate relative movement of pedicle screw during surgery application. The gliding hole shape is then geometrically complex. The gliding hole manufactured using machining processes used to employ ball-nose cutting tool. Then, production cost is expensive due to long production time. This study proposed to increase productivity of DCP products by introducing forming process (cold forming). The forming process used to involve any press tool devices. In the closed die forming press tool is designed with little allowance, then work-pieces is trapped in the mould after forming. Therefore, it is very important to determine hole geometry and dimensions of raw material in order to success on forming process. This study optimized the hole sizes with both geometry analytics and experiments. The success of the forming process was performed by increasing the holes size on the raw materials. The holes size need to be prepared is diameter of 5.5 mm with a length of 11.4 mm for the plate thickness 3 mm and diameter of 6 mm with a length of 12.5 mm for the plate thickness 4 mm.

  5. Leucyl-tRNA synthetase editing domain functions as a molecular rheostat to control codon ambiguity in Mycoplasma pathogens.

    PubMed

    Li, Li; Palencia, Andrés; Lukk, Tiit; Li, Zhi; Luthey-Schulten, Zaida A; Cusack, Stephen; Martinis, Susan A; Boniecki, Michal T

    2013-03-05

    Mycoplasma leucyl-tRNA synthetases (LeuRSs) have been identified in which the connective polypeptide 1 (CP1) amino acid editing domain that clears mischarged tRNAs are missing (Mycoplasma mobile) or highly degenerate (Mycoplasma synoviae). Thus, these enzymes rely on a clearance pathway called pretransfer editing, which hydrolyzes misactivated aminoacyl-adenylate intermediate via a nebulous mechanism that has been controversial for decades. Even as the sole fidelity pathway for clearing amino acid selection errors in the pathogenic M. mobile, pretransfer editing is not robust enough to completely block mischarging of tRNA(Leu), resulting in codon ambiguity and statistical proteins. A high-resolution X-ray crystal structure shows that M. mobile LeuRS structurally overlaps with other LeuRS cores. However, when CP1 domains from different aminoacyl-tRNA synthetases and origins were fused to this common LeuRS core, surprisingly, pretransfer editing was enhanced. It is hypothesized that the CP1 domain evolved as a molecular rheostat to balance multiple functions. These include distal control of specificity and enzyme activity in the ancient canonical core, as well as providing a separate hydrolytic active site for clearing mischarged tRNA.

  6. Synergism between upregulation of Rab7 and inhibition of autophagic degradation caused by mycoplasma facilitates intracellular mycoplasma infection.

    PubMed

    Hu, Xiaopeng; Yu, Jie; Zhou, Xiang; Li, Zhaoming; Xia, Yun; Luo, Zhiyong; Wu, Yaqun

    2014-03-01

    Following fusion of a mycoplasma with a host cell membrane, the inserted components of mycoplasma may then be transported through the endocytic pathway. However, the effects of mycoplasmas on the host cell endomembrane system are largely unknown. In this study, mycoplasma‑induced changes in the dynamics of endocytic and autophagic systems were investigated. Endocytosis and autophagy are two major processes involved in the survival of intracellular prokaryotic pathogens. It was found that, immediately following infection, mycoplasmas induce endocytosis in the host cell; however, in the long term the mycoplasmas suppress turnover of the components of the endocytic pathway. Immunofluorescence microscopy revealed that Rab7 and LC3‑II are recruited to the intracellular mycoplasma‑containing compartments. Western blot analysis and quantitative reverse transcription-polymerase chain reaction (qPCR) showed that mycoplasmas increase expression of Rab7 by upregulating transcription, but increase levels of LC3‑II and p62 by post‑translational regulation. Furthermore, it was demonstrated that mycoplasma infection causes inhibition of autophagic degradation of LC3‑II and p62. In addition, it was found that upregulation of Rab7 and inhibition of autophagic degradation synergistically contributes to intracellular mycoplasma accumulation. In conclusion, these findings suggest that mycoplasmas may manipulate host cell endosomal and autophagic systems in order to facilitate intracellular infection.

  7. [Refinement and study of the performance of a "Mycoplasma UG" kit for the research on urogenital Mycoplasmas].

    PubMed

    Melzi, A; Atieh, S; Benyahia, H

    1998-01-01

    The pathogenic role of genital Mycoplasmas is no more disputably. The diagnosis is based on the culture which may present some technical difficulties. The present study consist in a perfecting of a miniaturised system called "Mycoplasma UG" for the research, identification and titration of genital Mycoplasmas. The performance of the kit is studied with an important number of different types samples by comparison with the commercial kit "Mycoplasma Duo" and the classic reference method. The results obtained are satisfactory and constitute an important element in favour of a more advanced validation before the kit's trading.

  8. [Localization of the division protein FtsZ in mycoplasma cells Mycoplasma hominis].

    PubMed

    Vishniakov, I E; Borkhsenius, S N; Basovskiĭ, Iu I; Levitskiĭ, S A; Lazarev, V N; Snigirevskaia, E S; Komissarchik, Ia Iu

    2009-01-01

    Localization of the protein FtsZ in Mycoplasma hominis cells was determined. Ultra thin sections were treated by rabbit polyclonal antibodies against FtsZ M. hominis: a conjugate of protein A with colloidal gold particles was used instead of secondary antibodies. Considerable polymorphism of cells was seen on electron microscopy pictures of M. hominis cells, which is typical for mycoplasmas. Among a wide variety of cell shapes we distinguished dumbbell-shaped dividing cells, and the cells connected with each other with the aid of thin membrane tubules (former constrictions). Dominants distribution of the label in the constriction area of dividing M. hominis cells and in the area of the thin membrane tubules was observed. We revealed the cross septum in the mycoplasma cells for the first time, as well as the gold labeling of this structure. Furthermore, in some rounded and oval cells colloidal gold particles labeled the whole plasma membrane in ring-shaped manner. Probably, the label in these cases marks a submembrane contractile ring (Z-ring). The facts mentioned above confirm that FtsZ of M. hominis plays an active role in the mycoplasma cytokinesis. In a series of cases spiral-like distribution of gold particles was observed. Probably, FtsZ protofilaments in M. hominis cells can form spiral structures similar to Z-spirals of Bacillus subtilis and Escherichia coli. Its presence in mycoplasma cells may be considered as an important argument in favour of model of Z-ring assembling through reorganization of Z-spirals. FtsZ also may participate in maintenance of mycoplasma cell shape (membrane localization).

  9. Development of Mycoplasma hyopneumoniae Recombinant Vaccines.

    PubMed

    Marchioro, Silvana Beutinger; Simionatto, Simone; Dellagostin, Odir

    2016-01-01

    Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia (EP), a disease that affects swine production worldwide. Vaccination is the most cost-effective strategy for the control and prevention of the disease. Research using genome-based approach has the potential to elucidate the biology and pathogenesis of M. hyopneumoniae and contribute to the development of more effective vaccines. Here, we describe the protocol for developing M. hyopneumoniae recombinant vaccines using reverse vaccinology approaches.

  10. An epornitic of Mycoplasma gallisepticum in turkeys.

    PubMed

    Mason, S J; Maiers, J D

    1984-01-01

    A major epornitic of Mycoplasma gallisepticum occurred in the Monroe, North Carolina, area between January and June of 1983. The outbreak involved 304,000 turkeys of various ages, which were slaughtered in the eradication program at a cost of more than $550,000 to growers and poultry companies. An infected peafowl was the likely source of infection on the first farm. Traffic between farms by growers and company personnel was theorized to be the means of further spread.

  11. Mycoplasma bovis arthritis and pneumonia in calves.

    PubMed

    2017-03-18

    Mycoplasma bovis arthritis and pneumonia in six-month-old calvesSudden deaths in housed suckler cows due to hypomagnesaemiaBovine respiratory syncytial virus infection in two-year-old heifersBovine abortion associated with Parachlamydia speciesFibrinous pericarditis due to Aeromonas hydrophila in weaner pigsThese are among matters discussed in the disease surveillance report for December 2016 from SAC Consulting: Veterinary Services (SAC C VS). British Veterinary Association.

  12. Simultaneous Detection of Mycoplasma pneumoniae, Mycoplasma hominis and Mycoplasma arthritidis in Synovial Fluid of Patients with Rheumatoid Arthritis by Multiplex PCR.

    PubMed

    Ataee, Ramezan Ali; Golmohammadi, Reza; Alishiri, Gholam Hossein; Mirnejad, Reza; Najafi, Ali; Esmaeili, Davood; Jonaidi-Jafari, Nematollah

    2015-06-01

    It has been recognized that infectious agents, such as different bacteria and viruses, may play a role in the developing of rheumatoid arthritis (RA). Recently, the mycoplasma species has been implicated in the pathogenesis of RA. The aim of this study was to design a multiplex PCR for rapid and simultaneous detection of Mycoplasma pneumoniae, Mycoplasma hominis, and Mycoplasma arthritidis in the synovial fluid of patients with rheumatoid arthritis (RA). A total of 131 synovial fluid (SF) samples from patients with RA were assayed. Mycoplasma pneumoniae (ATCC: 29342), M. hominis (native strain), and the synthetic complete genome of M. arthritidis mitogen (MAM) superantigen were used as controls. All SF samples were subjected to DNA extraction separately and multiplex PCR was performed. The PCR products were confirmed by sequencing. The designed multiplex PCR was able to detect M. pneumoniae, M. hominis, and M. arthritidis in the SF of patients with RA with a frequency of 30 (22.9%), 23 (17.5%) and 13 (9.9%), respectively. In this study, the overall detection of the Mycoplasma species in RA patients was 53.4%; thus, we recommend the application of multiplex PCR assays when searching for a specific anti mycoplasma treatment for RA patients.

  13. Mycoplasma gallisepticum invades chicken erythrocytes during infection.

    PubMed

    Vogl, Gunther; Plaickner, Astrid; Szathmary, Susan; Stipkovits, László; Rosengarten, Renate; Szostak, Michael P

    2008-01-01

    Recently, it was demonstrated using in vitro assays that the avian pathogen Mycoplasma gallisepticum is able to invade nonphagocytic cells. It was also shown that this mycoplasma can survive and multiply intracellularly for at least 48 h and that this cell invasion capacity contributes to the systemic spread of M. gallisepticum from the respiratory tract to the inner organs. Using the gentamicin invasion assay and a differential immunofluorescence technique combined with confocal laser scanning microscopy, we were able to demonstrate in in vitro experiments that M. gallisepticum is also capable of invading sheep and chicken erythrocytes. The frequencies of invasion of three well-defined M. gallisepticum strains were examined over a period of 24 h, and a significant increase in invasiveness occurred after 8 h of infection. In addition, blood samples derived from chickens experimentally infected via the aerosol route with the virulent strain M. gallisepticum R(low) were analyzed. Surprisingly, M. gallisepticum R(low) was detected in the bloodstream of infected chickens by nested PCR, as well as by differential immunofluorescence and interference contrast microscopy that showed that mycoplasmas were not only on the surface but also inside chicken erythrocytes. This finding provides novel insight into the pathomechanism of M. gallisepticum and may have implications for the development of preventive strategies.

  14. Mycoplasma genitalium: from Chrysalis to Multicolored Butterfly

    PubMed Central

    Taylor-Robinson, David; Jensen, Jørgen Skov

    2011-01-01

    Summary: The history, replication, genetics, characteristics (both biological and physical), and factors involved in the pathogenesis of Mycoplasma genitalium are presented. The latter factors include adhesion, the influence of hormones, motility, possible toxin production, and immunological responses. The preferred site of colonization, together with current detection procedures, mainly by PCR technology, is discussed. The relationships between M. genitalium and various diseases are highlighted. These diseases include acute and chronic nongonococcal urethritis, balanoposthitis, chronic prostatitis, and acute epididymitis in men and urethritis, bacterial vaginosis, vaginitis, cervicitis, pelvic inflammatory disease, and reproductive disease in women. A causative relationship, or otherwise strong association, between several of these diseases and M. genitalium is apparent, and the extent of this, on a subjective basis, is presented; also provided is a comparison between M. genitalium and two other genital tract-orientated mollicutes, namely, Mycoplasma hominis, the first mycoplasma of human origin to be discovered, and Ureaplasma species. Also discussed is the relationship between M. genitalium and infertility and also arthritis in both men and women, as is infection in homosexual and immunodeficient patients. Decreased immunity, as in HIV infections, may enhance mycoplasmal detection and increase disease severity. Finally, aspects of the antimicrobial susceptibility and resistance of M. genitalium, together with the treatment and possible prevention of mycoplasmal disease, are discussed. PMID:21734246

  15. Characterization of Canine Mycoplasmas by Polyacrylamide Gel Electrophoresis and Immunodiffusion

    PubMed Central

    Armstrong, D.; Yu, B.

    1970-01-01

    Canine mycoplasmas which had been characterized by biological and serological methods were further studied by using polyacrylamide gel electrophoresis (PGE) and double diffusion in agar gel. The three dog mycoplasmas previously characterized, Mycoplasma canis, M. maculosum, and M. spumans showed distinctive patterns by PGE. Five additional representative isolates from dogs had been characterized serologically and biologically into three new groups, A, C, and D. An additional mycoplasma (group B) was indistinguishable from M. canis by growth inhibition and PGE but was more broadly reactive with field isolates serologically. The group A organisms were distinctive in pattern and similar to those studied by Razin and Rottem, tentatively designated M. edwardii. The group C organisms were represented by two isolates which were similar by fluorescent-antibody studies but different by growth inhibition tests. These two isolates were also different from each other by PGE. The group D serotypes were also distinctive by PGE from all other dog mycoplasmas tested. It was found, during these studies, that two different mycoplasmas showed different PGE patterns at different intervals during incubation. Immunodiffusion studies showed a relationship among all the canine mycoplasmas, and bands of nonidentity between the two group C mycoplasmas were demonstrated. Images PMID:4990761

  16. 21 CFR 866.3375 - Mycoplasma spp. serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... infection to mild or severe upper respiratory disease, ear infection, and bronchial pneumonia. (b.... The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Mycoplasma and provides epidemiological information on diseases caused by these microorganisms. Mycoplasma...

  17. 21 CFR 866.3375 - Mycoplasma spp. serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... infection to mild or severe upper respiratory disease, ear infection, and bronchial pneumonia. (b.... The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Mycoplasma and provides epidemiological information on diseases caused by these microorganisms. Mycoplasma...

  18. 21 CFR 866.3375 - Mycoplasma spp. serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... infection to mild or severe upper respiratory disease, ear infection, and bronchial pneumonia. (b.... The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Mycoplasma and provides epidemiological information on diseases caused by these microorganisms. Mycoplasma...

  19. 21 CFR 866.3375 - Mycoplasma spp. serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... infection to mild or severe upper respiratory disease, ear infection, and bronchial pneumonia. (b.... The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Mycoplasma and provides epidemiological information on diseases caused by these microorganisms. Mycoplasma...

  20. 21 CFR 866.3375 - Mycoplasma spp. serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... infection to mild or severe upper respiratory disease, ear infection, and bronchial pneumonia. (b.... The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Mycoplasma and provides epidemiological information on diseases caused by these microorganisms. Mycoplasma...

  1. Mycoplasma hominis, a Rare but True Cause of Infective Endocarditis.

    PubMed

    Gagneux-Brunon, Amandine; Grattard, Florence; Morel, Jerome; Suy, Florence; Fuzellier, Jean-François; Verhoeven, Paul; Cazorla, Celine; Guglielminotti, Claire; Fresard, Anne; Lucht, Frederic; Botelho-Nevers, Elisabeth

    2015-09-01

    Mycoplasma spp. are rarely recognized agents of infective endocarditis. We report a case of Mycoplasma hominis prosthetic valve endocarditis diagnosed by 16S ribosomal DNA (rDNA) PCR and culture of valves in a 74-year-old man. We reviewed the literature and found only 8 other cases reported.

  2. "Candidatus Mycoplasma haemomacaque" and Bartonella quintana bacteremia in cynomolgus monkeys.

    PubMed

    Maggi, Ricardo G; Mascarelli, Patricia E; Balakrishnan, Nandhakumar; Rohde, Cynthia M; Kelly, Catherine M; Ramaiah, Lila; Leach, Michael W; Breitschwerdt, Edward B

    2013-05-01

    Here, we report latent infections with Bartonella quintana and a hemotropic Mycoplasma sp. in a research colony of cynomolgus monkeys (Macaca fascicularis). Sequence alignments, evolutionary analysis, and signature nucleotide sequence motifs of the hemotropic Mycoplasma 16S rRNA and RNase P genes indicate the presence of a novel organism.

  3. Mycoplasma hominis, a Rare but True Cause of Infective Endocarditis

    PubMed Central

    Grattard, Florence; Morel, Jerome; Suy, Florence; Fuzellier, Jean-François; Verhoeven, Paul; Cazorla, Celine; Guglielminotti, Claire; Fresard, Anne; Lucht, Frederic; Botelho-Nevers, Elisabeth

    2015-01-01

    Mycoplasma spp. are rarely recognized agents of infective endocarditis. We report a case of Mycoplasma hominis prosthetic valve endocarditis diagnosed by 16S ribosomal DNA (rDNA) PCR and culture of valves in a 74-year-old man. We reviewed the literature and found only 8 other cases reported. PMID:26135868

  4. Competitor internal standards for quantitative detection of mycoplasma DNA.

    PubMed

    Sidhu, M K; Rashidbaigi, A; Testa, D; Liao, M J

    1995-05-01

    Homologous internal controls were used as competitor DNA in the polymerase chain reaction for the quantitative detection of mycoplasma DNA. PCR primer sets were designed on the basis of the most conserved nucleotide sequences of the 16S rRNA gene of mycoplasma species. Amplification of this gene was examined in five different mycoplasma species: Mycoplasma orale, M. hyorhinus, M. synoviae, M. gallisepticum and M. pneumoniae. To evaluate the primers, a number of different cell lines were assayed for the detection of mycoplasma infections. All positive cell lines showed a distinct product on agarose gels while uninfected cells showed no DNA amplification. Neither bacterial nor eukaryotic DNA produced any cross-reaction with the primers used, thus confirming their specificity. Internal control DNA to be used for quantitation was constructed by modifying the sizes of the wild-type amplified products and cloning them in plasmid vectors. These controls used the same primer binding sites as the wild-type and the amplified products were differentiated by a size difference. The detection limits for all the mycoplasma species by competitive quantitative PCR were estimated to range from 4 to 60 genome copies per assay as determined by ethidium bromide-stained agarose gels. These internal standards also serve as positive controls in PCR-based detection of mycoplasma DNA, and therefore accidental contamination of test samples with wild-type positive controls can be eliminated. The quantitative PCR method developed will be useful in monitoring the progression and significance of mycoplasma in the disease process.

  5. In vitro susceptibilities of Mycoplasma genitalium to antibiotics.

    PubMed Central

    Renaudin, H; Tully, J G; Bebear, C

    1992-01-01

    The susceptibilities of seven clinical isolates of Mycoplasma genitalium and three strains of Mycoplasma pneumoniae to a variety of antibiotics were examined by an agar dilution method. Macrolides, pristinamycin, and tetracyclines were very active against both species. Sparfloxacin was the most active quinolone tested. None of the 21 antibiotics tested had differential activity toward the two organisms. PMID:1503451

  6. [Role of mycoplasmas in urogenital tract infections and their complications].

    PubMed

    Kłosowska, Wioletta Marta; Zdrodowska-Stefanow, Bozena; Wilkowska-Trojniel, Marta

    2005-02-01

    In the literature from recent years it is stressed the significant epidemiological and clinical role of the sexually transmitted infections caused by so called "new generation" pathogens including mycoplasmas. The paper gives a review of the current literature concerning the epidemiology, clinical presentation, diagnosis and therapy of the infections of urogenital tract caused by mycoplasmas.

  7. 9 CFR 113.28 - Detection of mycoplasma contamination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Detection of mycoplasma contamination. 113.28 Section 113.28 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... mycoplasma medium. In the case of a cell line or a sample of primary cells, the inoculum shall consist of the...

  8. 9 CFR 113.28 - Detection of mycoplasma contamination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Detection of mycoplasma contamination. 113.28 Section 113.28 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... mycoplasma medium. In the case of a cell line or a sample of primary cells, the inoculum shall consist of the...

  9. Motor-substrate interactions in mycoplasma motility explains non-Arrhenius temperature dependence.

    PubMed

    Chen, Jing; Neu, John; Miyata, Makoto; Oster, George

    2009-12-02

    Mycoplasmas exhibit a novel, substrate-dependent gliding motility that is driven by approximately 400 "leg" proteins. The legs interact with the substrate and transmit the forces generated by an assembly of ATPase motors. The velocity of the cell increases linearly by nearly 10-fold over a narrow temperature range of 10-40 degrees C. This corresponds to an Arrhenius factor that decreases from approximately 45 k(B)T at 10 degrees C to approximately 10 k(B)T at 40 degrees C. On the other hand, load-velocity curves at different temperatures extrapolate to nearly the same stall force, suggesting a temperature-insensitive force-generation mechanism near stall. In this article, we propose a leg-substrate interaction mechanism that explains the intriguing temperature sensitivity of this motility. The large Arrhenius factor at low temperature comes about from the addition of many smaller energy barriers arising from many substrate-binding sites at the distal end of the leg protein. The Arrhenius dependence attenuates at high temperature due to two factors: 1), the reduced effective multiplicity of energy barriers intrinsic to the multiple-site binding mechanism; and 2), the temperature-sensitive weakly facilitated leg release that curtails the power stroke. The model suggests an explanation for the similar steep, sub-Arrhenius temperature-velocity curves observed in many molecular motors, such as kinesin and myosin, wherein the temperature behavior is dominated not by the catalytic biochemistry, but by the motor-substrate interaction.

  10. Structural characterization of the NAP; the major adhesion complex of the human pathogen Mycoplasma genitalium.

    PubMed

    Scheffer, Margot P; Gonzalez-Gonzalez, Luis; Seybert, Anja; Ratera, Mercè; Kunz, Michael; Valpuesta, José M; Fita, Ignacio; Querol, Enrique; Piñol, Jaume; Martín-Benito, Jaime; Frangakis, Achilleas S

    2017-09-01

    Mycoplasma genitalium, the causative agent of non-gonococcal urethritis and pelvic inflammatory disease in humans, is a small eubacterium that lacks a peptidoglycan cell wall. On the surface of its plasma membrane is the major surface adhesion complex, known as NAP that is essential for adhesion and gliding motility of the organism. Here, we have performed cryo-electron tomography of intact cells and detergent permeabilized M. genitalium cell aggregates, providing sub-tomogram averages of free and cell-attached NAPs respectively, revealing a tetrameric complex with two-fold rotational (C2) symmetry. Each NAP has two pairs of globular lobes (named α and β lobes), arranged as a dimer of heterodimers with each lobe connected by a stalk to the cell membrane. The β lobes are larger than the α lobes by 20%. Classification of NAPs showed that the complex can tilt with respect to the cell membrane. A protein complex containing exclusively the proteins P140 and P110, was purified from M. genitalium and was structurally characterized by negative-stain single particle EM reconstruction. The close structural similarity found between intact NAPs and the isolated P140/P110 complexes, shows that dimers of P140/P110 heterodimers are the only components of the extracellular region of intact NAPs in M. genitalium. © 2017 John Wiley & Sons Ltd.

  11. Alice in Wonderland syndrome associated with mycoplasma infection.

    PubMed

    Omata, Taku; Fujii, Katsunori; Kuroki, Haruo; Shimojo, Naoki

    2016-10-01

    Alice in Wonderland syndrome (AIWS) is a rare condition in which patients report distorted size perception of objects and their own bodies. Although specific causes and pathology have not been elucidated, an association between AIWS and infection has been suggested. To our knowledge, mycoplasma-induced AIWS has not been examined. A girl aged 7 years 11 months presented with fever (temperature, 40°C) and cough. Although the fever disappeared after approximately 10 days, she complained that her mother's face suddenly appeared smaller to her. Subsequently, she complained that objects intermittently appeared smaller than normal. Particle agglutination test indicated elevated serum antibodies against Mycoplasma pneumoniae. The patient was therefore diagnosed the patient with AIWS secondary to mycoplasma infection. Although mycoplasma infection is known to cause various central nervous system symptoms, this is the first report involving AIWS, suggesting that mycoplasma could affect visual function in children.

  12. Putative essential and core-essential genes in Mycoplasma genomes.

    PubMed

    Lin, Yan; Zhang, Randy Ren

    2011-01-01

    Mycoplasma, which was used to create the first "synthetic life", has been an important species in the emerging field, synthetic biology. However, essential genes, an important concept of synthetic biology, for both M. mycoides and M. capricolum, as well as 14 other Mycoplasma with available genomes, are still unknown. We have developed a gene essentiality prediction algorithm that incorporates information of biased gene strand distribution, homologous search and codon adaptation index. The algorithm, which achieved an accuracy of 80.8% and 78.9% in self-consistence and cross-validation tests, respectively, predicted 5880 essential genes in the 16 Mycoplasma genomes. The intersection set of essential genes in available Mycoplasma genomes consists of 153 core essential genes. The predicted essential genes (available from pDEG, tubic.tju.edu.cn/pdeg) and the proposed algorithm can be helpful for studying minimal Mycoplasma genomes as well as essential genes in other genomes.

  13. Putative essential and core-essential genes in Mycoplasma genomes

    PubMed Central

    Lin, Yan; Zhang, Randy Ren

    2011-01-01

    Mycoplasma, which was used to create the first “synthetic life”, has been an important species in the emerging field, synthetic biology. However, essential genes, an important concept of synthetic biology, for both M. mycoides and M. capricolum, as well as 14 other Mycoplasma with available genomes, are still unknown. We have developed a gene essentiality prediction algorithm that incorporates information of biased gene strand distribution, homologous search and codon adaptation index. The algorithm, which achieved an accuracy of 80.8% and 78.9% in self-consistence and cross-validation tests, respectively, predicted 5880 essential genes in the 16 Mycoplasma genomes. The intersection set of essential genes in available Mycoplasma genomes consists of 153 core essential genes. The predicted essential genes (available from pDEG, tubic.tju.edu.cn/pdeg) and the proposed algorithm can be helpful for studying minimal Mycoplasma genomes as well as essential genes in other genomes. PMID:22355572

  14. Significance of Genital Mycoplasmas in Pelvic Inflammatory Disease: Innocent Bystander!

    PubMed Central

    Harmanli, Ozgur H.; Nyirjesy, Paul; Reece, E. Albert

    1996-01-01

    Objective: Our objective was to determine the role of Mycoplasma hominis and Ureaplasma urealyticum in pelvic inflammatory disease (PID). Methods: The clinical and microbiologic variables in 114 patients with a clinical diagnosis of PID were compared prospectively according to the isolation of M. hominis and U. urealyticum from their endometrial cavities. Results: The groups were epidemiologically well matched. Clinical parameters such as temperature, leukocyte count, erythrocyte count, and C-reactive protein on admission and length of hospital stay were similar in the patients, regardless of their mycoplasma status. A significant percentage of the patients either continued or started to harbor genital mycoplasmas after the resolution of PID without any significant clinical sequelae. Conclusions: The presence of genital mycoplasmas does not change the clinical presentation and course of PID. Both M. hominis and U. urealyticum can persist or colonize the endometrium after complete recovery from PID. Therefore, the genital mycoplasmas do not seem to have a dominant pathogenic role in PID. PMID:18476105

  15. Use of Real-Time PCR To Detect and Quantify Mycoplasma haemofelis and “Candidatus Mycoplasma haemominutum” DNA

    PubMed Central

    Tasker, Séverine; Helps, Chris R.; Day, Michael J.; Gruffydd-Jones, Tim J.; Harbour, Dave A.

    2003-01-01

    A real-time PCR assay using Taqman probes was developed to detect and quantify Mycoplasma haemofelis and “Candidatus Mycoplasma haemominutum” in feline blood samples. The assay was rapid and sensitive and was successfully used to monitor the in vivo kinetics of cats experimentally infected with each species. PMID:12517888

  16. Hemotropic mycoplasmas in little brown bats (Myotis lucifugus).

    PubMed

    Mascarelli, Patricia E; Keel, Michael K; Yabsley, Michael; Last, Lisa A; Breitschwerdt, Edward B; Maggi, Ricardo G

    2014-03-24

    Hemotropic mycoplasmas are epicellular erythrocytic bacteria that can cause infectious anemia in some mammalian species. Worldwide, hemotropic mycoplasmas are emerging or re-emerging zoonotic pathogens potentially causing serious and significant health problems in wildlife. The objective of this study was to determine the molecular prevalence of hemotropic Mycoplasma species in little brown bats (Myotis lucifugus) with and without Pseudogymnoascus (Geomyces) destrucans, the causative agent of white nose syndrome (WNS) that causes significant mortality events in bats. In order to establish the prevalence of hemotropic Mycoplasma species in a population of 68 little brown bats (Myotis lucifugus) with (n = 53) and without (n = 15) white-nose syndrome (WNS), PCR was performed targeting the 16S rRNA gene. The overall prevalence of hemotropic Mycoplasmas in bats was 47%, with similar (p = 0.5725) prevalence between bats with WNS (49%) and without WNS (40%). 16S rDNA sequence analysis (~1,200 bp) supports the presence of a novel hemotropic Mycoplasma species with 91.75% sequence homology with Mycoplasma haemomuris. No differences were found in gene sequences generated from WNS and non-WNS animals. Gene sequences generated from WNS and non-WNS animals suggest that little brown bats could serve as a natural reservoir for this potentially novel Mycoplasma species. Currently, there is minimal information about the prevalence, host-specificity, or the route of transmission of hemotropic Mycoplasma spp. among bats. Finally, the potential role of hemotropic Mycoplasma spp. as co-factors in the development of disease manifestations in bats, including WNS in Myotis lucifugus, remains to be elucidated.

  17. Gravity gliding in the Bay of Mecklenburg? - New seismic data at the North German Basin margin

    NASA Astrophysics Data System (ADS)

    Huebscher, Christian; Damm, Volkmar; Engels, Martin; Juhlin, Christopher; Krawczyk, Charlotte; Malinowski, Michal; Noack, Vera; Schnabel, Michael; Seidel, Elisabeth

    2017-04-01

    the central Mecklenburg Bay to the Skurup Block covers the northeastern North German Basin and its marginal setting where several fault systems are present. The Agricola fault system is a set of arcuate faults in the Post-Permian strata which emerged above along the pinch-out line of the mobile salt. Faults reach partly up to the seafloor suggesting recent displacement. Fault planes dip mainly towards the basin. These faults can well be understood as the consequence of salt gliding towards the basin center, hence, as the consequence of gravity gliding. The Werre and Prerow fault systems evolved above a salt anticline on top of the Grimmen High. A first major halotectonic pulse is suggested for the upper Triassic which led to salt depletion and enhanced deposition. During the Cretaceous inversion of the Grimmen High, a salt pillow emerged between both fault systems when the salt moved towards northeast and southwest. The absence of significant fault displacements beneath the salt pillows in the Mecklenburg bay is further consistent with the gravity gliding concept which explains salt pillow growth by thin-skinned shortening.

  18. Cyclic fatigue of instruments for endodontic glide path.

    PubMed

    Gambarini, Gianluca; Plotino, Gianluca; Sannino, GianPaolo; Grande, Nicola Maria; Giansiracusa, Alessio; Piasecki, Lucila; da Silva Neto, Ulisses Xavier; Al-Sudani, Dina; Testarelli, Luca

    2015-01-01

    Endodontic glide path is the creation of a smooth patency from canal orifice to apex, which can be performed manually or with small tapered NiTi rotary instruments. The use of stainless steel (SS) hand K-files inserted in a reciprocating handpiece can be a possible alternative to create a mechanical glide path. The aim of this study was to compare the cyclic fatigue resistance between SS K-files used in a reciprocating motion and NiTi rotary instruments in artificial curved canals. Ten SS size 15 K-files used with the M4 handpiece (SybronEndo, Glendora, CA, USA) and ten PathFiles (Maillefer-Dentsply, Ballaigues, CH, Switzerland) NiTi rotary instruments size 16, 0.02 taper were tested for resistance to cyclic fatigue. The time to fracture inside an artificial curved canal was recorded for each instrument. Data were analyzed by one-way ANOVA and Tukey HSD test. Mean time (and SD) to failure was 464 s (±40.4) for the Group PF (NiTi rotary PathFile), and 1049 s (±24.8) for the Group M4 (SS K-files reciprocating) with a statistically significant difference between the two groups (p = 0.033). The SS 15 K-files used with the M4 handpiece showed a significant greater resistance to cyclic fatigue when compared to the NiTi rotary PathFiles. Therefore, the use of small size SS files in a reciprocating motion might be a rational choice for the creation of a mechanical endodontic glide path in curved root canals.

  19. Aerodynamic characteristics of flying fish in gliding flight.

    PubMed

    Park, Hyungmin; Choi, Haecheon

    2010-10-01

    The flying fish (family Exocoetidae) is an exceptional marine flying vertebrate, utilizing the advantages of moving in two different media, i.e. swimming in water and flying in air. Despite some physical limitations by moving in both water and air, the flying fish has evolved to have good aerodynamic designs (such as the hypertrophied fins and cylindrical body with a ventrally flattened surface) for proficient gliding flight. Hence, the morphological and behavioral adaptations of flying fish to aerial locomotion have attracted great interest from various fields including biology and aerodynamics. Several aspects of the flight of flying fish have been determined or conjectured from previous field observations and measurements of morphometric parameters. However, the detailed measurement of wing performance associated with its morphometry for identifying the characteristics of flight in flying fish has not been performed yet. Therefore, in the present study, we directly measure the aerodynamic forces and moment on darkedged-wing flying fish (Cypselurus hiraii) models and correlated them with morphological characteristics of wing (fin). The model configurations considered are: (1) both the pectoral and pelvic fins spread out, (2) only the pectoral fins spread with the pelvic fins folded, and (3) both fins folded. The role of the pelvic fins was found to increase the lift force and lift-to-drag ratio, which is confirmed by the jet-like flow structure existing between the pectoral and pelvic fins. With both the pectoral and pelvic fins spread, the longitudinal static stability is also more enhanced than that with the pelvic fins folded. For cases 1 and 2, the lift-to-drag ratio was maximum at attack angles of around 0 deg, where the attack angle is the angle between the longitudinal body axis and the flying direction. The lift coefficient is largest at attack angles around 30∼35 deg, at which the flying fish is observed to emerge from the sea surface. From glide polar

  20. Animal flight dynamics I. Stability in gliding flight.

    PubMed

    Thomas, A L; Taylor, G K

    2001-10-07

    Stability is as essential to flying as lift itself, but previous discussions of how flying animals maintain stability have been limited in both number and scope. By developing the pitching moment equations for gliding animals and by discussing potential sources of roll and yaw stability, we consider the various sources of static stability used by gliding animals. We find that gliding animals differ markedly from aircraft in how they maintain stability. In particular, the pendulum stability provided when the centre of gravity lies below the wings is a much more important source of stability in flying animals than in most conventional aircraft. Drag-based stability also appears to be important for many gliding animals, whereas in aircraft, drag is usually kept to a minimum. One unexpected consequence of these differences is that the golden measure of static pitching stability in aircraft--the static margin--can only strictly be applied to flying animals if the equilibrium angle of attack is specified. We also derive several rules of thumb by which stable fliers can be identified. Stable fliers are expected to exhibit one or more of the following features: (1) Wings that are swept forward in slow flight. (2) Wings that are twisted down at the tips when swept back (wash-out) and twisted up at the tips when swept forwards (wash-in). (3) Additional lifting surfaces (canard, hindwings or a tail) inclined nose-up to the main wing if they lie forward of it, and nose-down if they lie behind it (longitudinal dihedral). Each of these predictions is directional--the opposite is expected to apply in unstable animals. In addition, animals with reduced stability are expected to display direct flight patterns in turbulent conditions, in contrast to the erratic flight patterns predicted for stable animals, in which large restoring forces are generated. Using these predictions, we find that flying animals possess a far higher degree of inherent stability than has generally been

  1. Radiation enhanced basal plane dislocation glide in GaN

    NASA Astrophysics Data System (ADS)

    Yakimov, Eugene B.; Vergeles, Pavel S.; Polyakov, Alexander Y.; Lee, In-Hwan; Pearton, Stephen J.

    2016-05-01

    A movement of basal plane segments of dislocations in GaN films grown by epitaxial lateral overgrowth under low energy electron beam irradiation (LEEBI) was studied by the electron beam induced current (EBIC) method. Only a small fraction of the basal plane dislocation segments were susceptible to irradiation and the movement was limited to relatively short distances. The effect is explained by the radiation enhanced dislocation glide (REDG) in the structure with strong pinning. A dislocation velocity under LEEBI with a beam current lower than 1 nA was estimated as about 10 nm/s. The results assuming the REDG for prismatic plane dislocations were presented.

  2. Repetition Pitch glide from the step pyramid at Chichen Itza.

    PubMed

    Bilsen, Frans A

    2006-08-01

    Standing at the foot of the Mayan step pyramid at Chichen Itza in Mexico, one can produce a pitchy "chirp" echo by handclapping. As exposed by Declercq et al. [J. Acoust. Soc. Am. 116, 3328-3335 (2004)], an acoustic model based on optical Bragg diffraction at a periodic structure cannot explain satisfactorily the chirp-echo sonogram. Alternatively, considering the echo as a sequence of reflections, and given the dimensions of the pyramid and source-receiver position, the chirp is predicted correctly as a Repetition Pitch glide of which the pitch height is continuously decreasing within 177 ms from 796 to 471 Hz-equivalent.

  3. Mollicutes in vaginal microbiology: Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum and Mycoplasma genitalium.

    PubMed

    Taylor-Robinson, David

    2017-03-02

    Mycoplasma hominis was isolated in 1937 from the human genital tract, followed 17 years later by Ureaplasma urealyticum and 27 years after that by Mycoplasma genitalium. The first two proved relatively easy to culture but the latter required a polymerase chain reaction assay for further studies. In sexually mature women, M. hominis may be found in the vagina/cervix of about 20-50%, ureaplasmas in 40-80% and M. genitalium in 0-5%. Some heterogeneity has been found among strains of all these species, sufficient to divide ureaplasmas into two species, namely U. urealyticum and Ureaplasma parvum. Studies in female mice show that sex hormones have a profound influence on colonization, multiplication and persistence of mycoplasmas/ureaplasmas in the genital tract and provoke the question, unanswered, of whether there is such an effect in the human tract. In women, there is no evidence that any of the mycoplasmal species stimulate an inflammatory vaginitis. M. hominis organisms increase hugely in number in the case of bacterial vaginosis (BV), and to a lesser extent so do ureaplasmas. Despite this, they have not been incriminated as a sole cause of BV. Evidence for the involvement of M. genitalium remains controversial. The strong association of BV with preterm birth raises the possibility that the genital mycoplasmas might play a part, but assurance that any do will be difficult to obtain. Detailed examination of the vaginal microbiome has not yet provided an answer. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  4. Gliding Motility of Babesia bovis Merozoites Visualized by Time-Lapse Video Microscopy

    PubMed Central

    Asada, Masahito; Goto, Yasuyuki; Yahata, Kazuhide; Yokoyama, Naoaki; Kawai, Satoru; Inoue, Noboru; Kaneko, Osamu; Kawazu, Shin-ichiro

    2012-01-01

    Background Babesia bovis is an apicomplexan intraerythrocytic protozoan parasite that induces babesiosis in cattle after transmission by ticks. During specific stages of the apicomplexan parasite lifecycle, such as the sporozoites of Plasmodium falciparum and tachyzoites of Toxoplasma gondii, host cells are targeted for invasion using a unique, active process termed “gliding motility”. However, it is not thoroughly understood how the merozoites of B. bovis target and invade host red blood cells (RBCs), and gliding motility has so far not been observed in the parasite. Methodology/Principal Findings Gliding motility of B. bovis merozoites was revealed by time-lapse video microscopy. The recorded images revealed that the process included egress of the merozoites from the infected RBC, gliding motility, and subsequent invasion into new RBCs. The gliding motility of B. bovis merozoites was similar to the helical gliding of Toxoplasma tachyzoites. The trails left by the merozoites were detected by indirect immunofluorescence assay using antiserum against B. bovis merozoite surface antigen 1. Inhibition of gliding motility by actin filament polymerization or depolymerization indicated that the gliding motility was driven by actomyosin dependent process. In addition, we revealed the timing of breakdown of the parasitophorous vacuole. Time-lapse image analysis of membrane-stained bovine RBCs showed formation and breakdown of the parasitophorous vacuole within ten minutes of invasion. Conclusions/Significance This is the first report of the gliding motility of B. bovis. Since merozoites of Plasmodium parasites do not glide on a substrate, the gliding motility of B. bovis merozoites is a notable finding. PMID:22506073

  5. New models of chronic synovitis in rabbits induced by mycoplasmas: microbiological, histopathological, and immunological observations on rabbits injected with Mycoplasma arthritidis and Mycoplasma pulmonis.

    PubMed Central

    Cole, B C; Griffiths, M M; Eichwald, E J; Ward, J R

    1977-01-01

    A dose-dependent chronic synovitis was induced in rabbit knees after the intra-articular injection of both Mycoplasma arthritidis and Mycoplasma pulmonis. The inflammation progressed from an initial acute phase at 1 week characterized by edema, infiltration of the synovium with monocytes and heterophils, and desquamation of lining cells, to a more chronic phase at 1 and 3 months, in which villus hyperplasia, lymph "nodules," mononuclear cell infiltration, fibroplasia, and collagen deposition were prominent. With one exception, mycoplasmas could no longer be cultivated from the joints 1 month postinoculation. Both mycoplasma species evoked a humoral antibody response that was more marked in synovial fluids than in peripheral blood. A cell-mediated immune reaction, as evidence by enhanced uptake by [3H]thymidine by sensitized blood, spleen, or node lymphocytes in the presence of homologous antigen, was detected only in rabbits injected with M. pulmonis. Lymphocytes taken from arthritic rabbits were no more cytotoxic toward synovial cells derived from normal or arthritic rabbits than were normal lymphocytes. The models of synovitis described in this study offer a convenient probe for determining the mechanisms of mycoplasma-induced inflammation, since they require only a single injection of the initiating agent and, in addition, utilize an animal host large enough for detailed investigation into the nature of mycoplasma/synovium interactions. Images PMID:873616

  6. Plastic deformation of tubular crystals by dislocation glide.

    PubMed

    Beller, Daniel A; Nelson, David R

    2016-09-01

    Tubular crystals, two-dimensional lattices wrapped into cylindrical topologies, arise in many contexts, including botany and biofilaments, and in physical systems such as carbon nanotubes. The geometrical principles of botanical phyllotaxis, describing the spiral packings on cylinders commonly found in nature, have found application in all these systems. Several recent studies have examined defects in tubular crystals associated with crystalline packings that must accommodate a fixed tube radius. Here we study the mechanics of tubular crystals with variable tube radius, with dislocations interposed between regions of different phyllotactic packings. Unbinding and separation of dislocation pairs with equal and opposite Burgers vectors allow the growth of one phyllotactic domain at the expense of another. In particular, glide separation of dislocations offers a low-energy mode for plastic deformations of solid tubes in response to external stresses, reconfiguring the lattice step by step. Through theory and simulation, we examine how the tube's radius and helicity affects, and is in turn altered by, the mechanics of dislocation glide. We also discuss how a sufficiently strong bending rigidity can alter or arrest the deformations of tubes with small radii.

  7. Plastic deformation of tubular crystals by dislocation glide

    NASA Astrophysics Data System (ADS)

    Beller, Daniel A.; Nelson, David R.

    2016-09-01

    Tubular crystals, two-dimensional lattices wrapped into cylindrical topologies, arise in many contexts, including botany and biofilaments, and in physical systems such as carbon nanotubes. The geometrical principles of botanical phyllotaxis, describing the spiral packings on cylinders commonly found in nature, have found application in all these systems. Several recent studies have examined defects in tubular crystals associated with crystalline packings that must accommodate a fixed tube radius. Here we study the mechanics of tubular crystals with variable tube radius, with dislocations interposed between regions of different phyllotactic packings. Unbinding and separation of dislocation pairs with equal and opposite Burgers vectors allow the growth of one phyllotactic domain at the expense of another. In particular, glide separation of dislocations offers a low-energy mode for plastic deformations of solid tubes in response to external stresses, reconfiguring the lattice step by step. Through theory and simulation, we examine how the tube's radius and helicity affects, and is in turn altered by, the mechanics of dislocation glide. We also discuss how a sufficiently strong bending rigidity can alter or arrest the deformations of tubes with small radii.

  8. Amoeboid cells use protrusions for walking, gliding and swimming.

    PubMed

    Van Haastert, Peter J M

    2011-01-01

    Amoeboid cells crawl using pseudopods, which are convex extensions of the cell surface. In many laboratory experiments, cells move on a smooth substrate, but in the wild cells may experience obstacles of other cells or dead material, or may even move in liquid. To understand how cells cope with heterogeneous environments we have investigated the pseudopod life cycle of wild type and mutant cells moving on a substrate and when suspended in liquid. We show that the same pseudopod cycle can provide three types of movement that we address as walking, gliding and swimming. In walking, the extending pseudopod will adhere firmly to the substrate, which allows cells to generate forces to bypass obstacles. Mutant cells with compromised adhesion can move much faster than wild type cells on a smooth substrate (gliding), but cannot move effectively against obstacles that provide resistance. In a liquid, when swimming, the extending pseudopods convert to side-bumps that move rapidly to the rear of the cells. Calculations suggest that these bumps provide sufficient drag force to mediate the observed forward swimming of the cell.

  9. Gliding arc in tornado using a reverse vortex flow

    SciTech Connect

    Kalra, Chiranjeev S.; Cho, Young I.; Gutsol, Alexander; Fridman, Alexander; Rufael, Tecle S.

    2005-02-01

    The present article reports a new gliding arc (GA) system using a reverse vortex flow ('tornado') in a cylindrical reactor (gliding arc in tornado, or GAT), as used to preserve the main advantages of traditional GA systems and overcome their main drawbacks. The primary advantages of traditional GA systems retained in the present GAT are the possibility to generate transitional plasma and to avoid considerable electrode erosion. In contrast to a traditional GA, the new GAT system ensures much more uniform gas treatment and has a significantly larger gas residence time in the reactor. The present article also describes the design of the new reactor and its stable operation regime when the variation of GAT current is very small. These features are understood to be very important for most viable applications. Additionally the GAT provides near-perfect thermal insulation from the reactor wall, indicating that the present GAT does not require the reactor wall to be constructed of high-temperature materials. The new GAT system, with its unique properties such as a high level of nonequilibrium and a large residence time, looks very promising for many industrial applications including fuel conversion, carbon dioxide conversion to carbon monoxide and oxygen, surface treatment, waste treatment, flame stabilization, hydrogen sulfide treatment, etc.

  10. The epidemiology of injury in hang-gliding and paragliding.

    PubMed

    Rekand, Tiina

    2012-01-01

    Para- and hang-gliding are modern air sports that developed in the 20th century. Performers should possess technical skills and manage certified equipment for successful flight. Injuries may happen during the take-off, flight and landing. PubMed was searched using the search terms 'paragliding' and/or 'hang-gliding'. The reference lists of articles identified in the search strategy were also searched for relevant articles. The most common injuries are fractures, dislocations or sprains in the extremities, followed by spinal and head traumas. Multiple injuries after accidents are common. Collision with electrical wires may cause burn injuries. Fatal outcomes are caused by brain injuries, spinal cord injuries at the cervical level or aorta rupture. Accidents happen because of risk-taking behavior, lack of education or use of self-modified equipment. Observational studies have suggested the need for protection of the head, trunk and lower extremities. The measures proposed are often based on conclusions of observational studies and not proven through randomized studies. Better education along with focusing on possible risk factors will probably diminish the risks of hang- and paragliding. Large denominator-based case series, case-control and population-based studies are needed for assessment of the risks of hang- and paragliding.

  11. The Gcm/Glide molecular and cellular pathway: new actors and new lineages.

    PubMed

    Laneve, Pietro; Delaporte, Claude; Trebuchet, Guillaume; Komonyi, Orban; Flici, Hakima; Popkova, Anna; D'Agostino, Giuseppe; Taglini, Francesca; Kerekes, Irene; Giangrande, Angela

    2013-03-01

    In Drosophila, the transcription factor Gcm/Glide plays a key role in cell fate determination and cellular differentiation. In light of its crucial biological impact, major efforts have been put for analyzing its properties as master regulator, from both structural and functional points of view. However, the lack of efficient antibodies specific to the Gcm/Glide protein precluded thorough analyses of its regulation and activity in vivo. In order to relieve such restraints, we designed an epitope-tagging approach to "FLAG"-recognize and analyze the functional protein both in vitro (exogenous Gcm/Glide) and in vivo (endogenous protein). We here (i) reveal a tight interconnection between the small RNA and the Gcm/Glide pathways. AGO1 and miR-1 are Gcm/Glide targets whereas miR-279 negatively controls Gcm/Glide expression (ii) identify a novel cell population, peritracheal cells, expressing and requiring Gcm/Glide. Peritracheal cells are non-neuronal neurosecretory cells that are essential in ecdysis. In addition to emphasizing the importance of following the distribution and the activity of endogenous proteins in vivo, this study provides new insights and a novel frame to understand the Gcm/Glide biology. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Temperature regulation of gliding motility in filamentous sulfur bacteria, Beggiatoa spp.

    PubMed

    Dunker, Rita; Røy, Hans; Jørgensen, Bo Barker

    2010-08-01

    The response of gliding motility to changing temperatures was studied in filaments of the large sulfur bacteria Beggiatoa from arctic, temperate and tropical marine environments. The general shape of the gliding speed vs. temperature curves from all three locations was similar, but differed in the maximal gliding speed of the filaments, optimum temperature and the temperature range of motility. The optimum temperature and the overall temperature range of gliding motility accorded to the climatic origin of the filaments with a high temperature range for tropical, an intermediate range for temperate, and a low temperature range for arctic filaments. The temperature-controlled decrease in gliding speed at low temperatures was reversible while the decline in speed at high temperatures was due to irreversible thermal damage in individual filaments. Filaments from the Arctic and cold-acclimatized filaments from the temperate zone were unaffected by transient freezing of the surrounding seawater. At in situ temperatures, filaments glided at 17-55% of the gliding speed at the optimum temperatures, indicating that they were well adapted to the temperature regime of their origin. Our results point towards an enzymatic control of temperature-dependent gliding motility.

  13. Effortful Pitch Glide: A Potential New Exercise Evaluated by Dynamic MRI

    ERIC Educational Resources Information Center

    Miloro, Keri Vasquez; Pearson, William G., Jr.; Langmore, Susan E.

    2014-01-01

    Purpose: The purpose of this study was to compare the biomechanics of the effortful pitch glide (EPG) with swallowing using dynamic MRI. The EPG is a combination of a pitch glide and a pharyngeal squeeze maneuver for targeting laryngeal and pharyngeal muscles. The authors hypothesized that the EPG would elicit significantly greater structural…

  14. Quadrupedal locomotor performance in two species of arboreal squirrels: predicting energy savings of gliding

    Treesearch

    Elizabeth A. Flaherty; Merav Ben-David; Winston P. Smith

    2010-01-01

    Gliding allows mammals to exploit canopy habitats of old-growth forests possibly as a means to save energy. To assess costs of quadrupedal locomotion for a gliding arboreal mammal, we used open-flow respirometry and a variable-speed treadmill to measure oxygen consumption and to calculate cost of transport, excess exercise oxygen consumption, and excess post-exercise...

  15. Gliding flight in snakes: non-equilibrium trajectory dynamics and kinematics

    NASA Astrophysics Data System (ADS)

    Socha, Jake; Miklasz, Kevin; Jafari, Farid; Vlachos, Pavlos

    2010-11-01

    For animal gliders that live in trees, a glide trajectory begins in free fall and, given sufficient space, transitions to equilibrium gliding with no net forces on the body. However, the dynamics of non-equilibrium gliding are not well understood. Of any terrestrial animal glider, snakes may exhibit the most complicated glide patterns resulting from their highly active undulatory behavior. Our aim was to determine the characteristics of snake gliding during the transition to equilibrium. We launched "flying" snakes (Chrysopelea paradisi) from a 15 m tower and recorded the mid-to-end portion of trajectories with four videocameras to reconstruct the snake's 3D body position. Additionally, we developed a simple analytical model of gliding assuming only steady-state forces of lift, drag and weight acting on the body and used it to explore effects of wing loading, lift-to-drag ratio, and initial velocity on trajectory dynamics. Despite the vertical space provided to transition to steady-state gliding, snakes did not exhibit equilibrium gliding and in fact displayed a net positive acceleration in the vertical axis.

  16. 14 CFR 29.71 - Helicopter angle of glide: Category B.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Helicopter angle of glide: Category B. 29... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.71 Helicopter angle of glide: Category B. For each category B helicopter, except multiengine helicopters meeting the...

  17. 14 CFR 29.71 - Helicopter angle of glide: Category B.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Helicopter angle of glide: Category B. 29... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.71 Helicopter angle of glide: Category B. For each category B helicopter, except multiengine helicopters meeting the...

  18. 14 CFR 29.71 - Helicopter angle of glide: Category B.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Helicopter angle of glide: Category B. 29... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.71 Helicopter angle of glide: Category B. For each category B helicopter, except multiengine helicopters meeting the...

  19. 14 CFR 29.71 - Helicopter angle of glide: Category B.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Helicopter angle of glide: Category B. 29... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.71 Helicopter angle of glide: Category B. For each category B helicopter, except multiengine helicopters meeting the...

  20. Effortful Pitch Glide: A Potential New Exercise Evaluated by Dynamic MRI

    ERIC Educational Resources Information Center

    Miloro, Keri Vasquez; Pearson, William G., Jr.; Langmore, Susan E.

    2014-01-01

    Purpose: The purpose of this study was to compare the biomechanics of the effortful pitch glide (EPG) with swallowing using dynamic MRI. The EPG is a combination of a pitch glide and a pharyngeal squeeze maneuver for targeting laryngeal and pharyngeal muscles. The authors hypothesized that the EPG would elicit significantly greater structural…

  1. The Selection of Glide Slope Antenna Patterns for Use in the Frequency Assignment Process

    DTIC Science & Technology

    1979-07-01

    3 CONIUcSIONS ---------------------------------------------------------- 5 RECOMMENDED ANTENNA...is therefore still required. Additional data would also be helpful on the A.I.L. Type 55 glide slope and the end-fire slotted cable system. 5 ...Inc.. June 30, 1970. 5 . FAA Preliminary Instruction Book TI 6750.44, "Glide Slope Antenna System, Part of Mark I Instrument Landirl System," FAA

  2. Evolution of gliding in Southeast Asian geckos and other vertebrates is temporally congruent with dipterocarp forest development

    PubMed Central

    Heinicke, Matthew P.; Greenbaum, Eli; Jackman, Todd R.; Bauer, Aaron M.

    2012-01-01

    Gliding morphologies occur in diverse vertebrate lineages in Southeast Asian rainforests, including three gecko genera, plus frogs, snakes, agamid lizards and squirrels. It has been hypothesized that repeated evolution of gliding is related to the dominance of Asian rainforest tree floras by dipterocarps. For dipterocarps to have influenced the evolution of gliding in Southeast Asian vertebrates, gliding lineages must have Eocene or later origins. However, divergence times are not known for most lineages. To investigate the temporal pattern of Asian gliding vertebrate evolution, we performed phylogenetic and molecular clock analyses. New sequence data for geckos incorporate exemplars of each gliding genus (Cosymbotus, Luperosaurus and Ptychozoon), whereas analyses of other vertebrate lineages use existing sequence data. Stem ages of most gliding vertebrates, including all geckos, cluster in the time period when dipterocarps came to dominate Asian tropical forests. These results demonstrate that a gliding/dipterocarp correlation is temporally viable, and caution against the assumption of early origins for apomorphic taxa. PMID:22977067

  3. Quantitative assessment of Mycoplasma hemadsorption activity by flow cytometry.

    PubMed

    García-Morales, Luis; González-González, Luis; Costa, Manuela; Querol, Enrique; Piñol, Jaume

    2014-01-01

    A number of adherent mycoplasmas have developed highly complex polar structures that are involved in diverse aspects of the biology of these microorganisms and play a key role as virulence factors by promoting adhesion to host cells in the first stages of infection. Attachment activity of mycoplasma cells has been traditionally investigated by determining their hemadsorption ability to red blood cells and it is a distinctive trait widely examined when characterizing the different mycoplasma species. Despite the fact that protocols to qualitatively determine the hemadsorption or hemagglutination of mycoplasmas are straightforward, current methods when investigating hemadsorption at the quantitative level are expensive and poorly reproducible. By using flow cytometry, we have developed a procedure to quantify rapidly and accurately the hemadsorption activity of mycoplasmas in the presence of SYBR Green I, a vital fluorochrome that stains nucleic acids, allowing to resolve erythrocyte and mycoplasma cells by their different size and fluorescence. This method is very reproducible and permits the kinetic analysis of the obtained data and a precise hemadsorption quantification based on standard binding parameters such as the dissociation constant K d. The procedure we developed could be easily implemented in a standardized assay to test the hemadsorption activity of the growing number of clinical isolates and mutant strains of different mycoplasma species, providing valuable data about the virulence of these microorganisms.

  4. [Female urogenital mycoplasma infection and drug sensitivity status in Changsha].

    PubMed

    Zuo, Cheng-xin; Huang, Jin-hua; Chen, Jing; Lu, Jian-yun; Xiang, Ya-ping

    2006-06-01

    To survey mycoplasma infection in female urogenital tract and analyze the drug sensitivity of mycoplasma in Changsha. Ureaplasma urealyticum (Uu) and Mycoplasma hominis (Mh) were detected in 6566 cases of female urogenital tract infection by means of mycoplasma culture and drug sensitivity reagent kit. Sensitivity tests for 10 antibiotics were also performed. A total of 2938 cases were mycoplasma-positive (positivity rate of 44.75%), including 2469 Uu-positive cases (37.6%), 52 Mh-positive cases (0.08%) and 417 cases positive for both Uu and Mh (6.35%). Josamycin, doxycycline, clarithromycin and azithromycin were more effective against Uu infection. Josamycin, doxycycline and thiamphenicol were more effective against Mh infection. Mixed infection with Uu and Mh was more resistant to most antibiotics but Josamycin and doxycycline. The female urogenital mycoplasma infection results mainly from Uu. Compared with simple Uu or Mh infection, mixed infection with Uu and Mh has significantly greater resistance to a wider variety of drugs. Josamycin and doxycycline are the primary choice for female urogenital mycoplasma infection in Changsha.

  5. Neutrophil histamine contributes to inflammation in mycoplasma pneumonia

    PubMed Central

    Xu, Xiang; Zhang, Dongji; Zhang, Hong; Wolters, Paul J.; Killeen, Nigel P.; Sullivan, Brandon M.; Locksley, Richard M.; Lowell, Clifford A.; Caughey, George H.

    2006-01-01

    Mycoplasmas cause chronic inflammation and are implicated in asthma. Mast cells defend against mycoplasma infection and worsen allergic inflammation, which is mediated partly by histamine. To address the hypothesis that mycoplasma provokes histamine release, we exposed mice to Mycoplasma pulmonis, comparing responses in wild-type and mast cell–deficient KitW-sh/KitW-sh (W-sh) mice. Low histamine levels in uninfected W-sh mice confirmed the conventional wisdom that mast cells are principal sources of airway and serum histamine. Although mycoplasma did not release histamine acutely in wild-type airways, levels rose up to 50-fold above baseline 1 week after infection in mice heavily burdened with neutrophils. Surprisingly, histamine levels also rose profoundly in infected W-sh lungs, increasing in parallel with neutrophils and declining with neutrophil depletion. Furthermore, neutrophils from infected airway were highly enriched in histamine compared with naive neutrophils. In vitro, mycoplasma directly stimulated histamine production by naive neutrophils and strongly upregulated mRNA encoding histidine decarboxylase, the rate-limiting enzyme in histamine synthesis. In vivo, treatment with antihistamines pyrilamine or cimetidine decreased lung weight and severity of pneumonia and tracheobronchitis in infected W-sh mice. These findings suggest that neutrophils, provoked by mycoplasma, greatly expand their capacity to synthesize histamine, thereby contributing to lung and airway inflammation. PMID:17158962

  6. RESPIRATORY PATHWAYS IN THE MYCOPLASMA II.

    PubMed Central

    VanDemark, P. J.; Smith, P. F.

    1964-01-01

    VanDemark, P. J. (University of South Dakota, Vermillion), and P. F. Smith. Respiratory pathways in the Mycoplasma. II. Pathway of electron transport during oxidation of reduced nicotinamide adenine dinucleotide by Mycoplasma hominis. J. Bacteriol. 88:122–129. 1964.—Unlike the flavin-terminated respiratory pathway of the fermentative Mycoplasma, the respiratory chain of the nonfermentative M. hominis strain 07 appears to be more complex, involving quinones and cytochromes in addition to flavins. In addition to reduction by reduced nicotine adenine dinucleotide (NADH) and reduced nicotine adenine dinucleotide phosphate, nonpyridine nucleotide-linked reduction of the respiratory chain of this organism occurred with succinate, lactate, and short-chained acyl coenzyme A derivatives as electron donors. Enzymes catalyzing the oxidation of NADH included an NADH oxidase, a diaphorase, a quinone reductase, and a cytochrome c reductase. The oxidation of NADH was sensitive to a variety of inhibitors, including 10−4m Atabrine, 10−3m sodium amytal, 10−5mp-chloromercuribenzoate, 10−4m antimycin A, and 10−4m potassium cyanide. The oxidase was resolved by the addition of 5% trichloroacetic acid and reactivated by the addition of flavin adenine dinucleotide but not flavin mononucleotide. The M. hominis sonic extract contained an NADH-coenzyme Q reductase. The oxidation of NADH was stimulated by the addition of either menadione or vitamin K2 (C35). The oxidase was inactivated by extraction with ether or irradiation at 360 mμ. The ether-inactivated enzyme was partially reactivated by the addition of “lipid” extract of the enzyme and coenzyme Q6. Difference spectra of the cell extracts revealed the presence of “b” and “a” type cytochromes. These cell extracts were found to contain a cyanide-and azide-sensitive cytochrome oxidase and catalase. PMID:14197876

  7. Cloning of the complete Mycoplasma pneumoniae genome.

    PubMed Central

    Wenzel, R; Herrmann, R

    1989-01-01

    The complete genome of Mycoplasma pneumoniae was cloned in an ordered library consisting of 34 overlapping or adjacent cosmids, one plasmid and two lambda phages. The genome size was determined by adding up the sizes of either the individual unique EcoRI restriction fragments of the gene bank or of the XhoI fragments of genomic M. pneumoniae DNA. The values from these calculations, 835 and 849 kbp, are in good agreement. An XhoI restriction map was constructed by identifying adjacent DNA fragments by probing with selected cosmid clones. Images PMID:2506532

  8. Laser radiation effects on Mycoplasma agalactiae

    NASA Astrophysics Data System (ADS)

    Dinu, Cerasela Z.; Grigoriu, Constantin; Dinescu, Maria; Pascale, Florentina; Popovici, Adrian; Gheorghescu, Lavinia; Cismileanu, Ana; Avram, Eugenia

    2002-08-01

    The biological effects of the laser radiation emitted by the Nd:YAG laser (second harmonic, wavelength 532 nm /fluence 32 mJ/cm2/pulse duration 6 ns) on the Mycoplasma agalactiae bacterium were studied. The radiation was found to intensify the multiplication of the bacteria irradiated in TRIS buffer (0.125 M), without however affecting the proteinic composition of the cell membrane. When the bacteria were irradiated in their growth medium (PPLO broth) being later cultivated on a solid medium (PPLO agar), the exclusive presence of the atypical colonies (granular and T-like ones) was noticed.

  9. The minimal gene complement of mycoplasma genitalium

    SciTech Connect

    Fraser, C.M.; Gocayne, J.D.; White, O.

    1995-10-20

    The complete nucleotide sequence (580,070 base pairs) of the Mycoplasma genitalium genome, the smallest known genome of any free-living organism, has been determined by whole-genome random sequencing and assembly. A total of only 470 predicted coding regions were identified that include genes required for DNA replication, transcription and translation, DNA repair, cellular transport, and energy metabolism. Comparison of this genome to that of Haemophilus influenzae suggests that differences in genome content are reflected as profound differences in physiology and metabolic capacity between these two organisms. 43 refs., 1 fig., 2 tabs.

  10. Ocular manifestations of Mycoplasma pneumoniae infection.

    PubMed

    Salzman, M B; Sood, S K; Slavin, M L; Rubin, L G

    1992-05-01

    Ocular manifestations of Mycoplasma pneumoniae infection, other than conjunctivitis, are uncommon. Optic disk swelling, optic nerve atrophy, retinal exudates and hemorrhages, and cranial nerve palsies have been infrequently reported. We describe a 15-year-old patient who developed bilateral optic disk edema and iritis during an acute infection with M. pneumoniae and review the world literature on findings associated with ocular manifestations of infection with this pathogen. Although our patient experienced complete resolution of iritis and optic disk edema after 6 weeks, several patients described in the literature have experienced permanent sequelae as a result of optic neuropathy.

  11. Neurological complications of Mycoplasma pneumoniae infection.

    PubMed

    Hely, M A; Williamson, P M; Terenty, T R

    1984-01-01

    This study documents five patients with neurological disease associated with evidence of recent Mycoplasma pneumoniae infection. Four patients had encephalitis associated with coma. Two of these had hemiparesis (one with dysphasia), one had seizures, and one had cerebellar and brainstem involvement. Two also had evidence of a radiculopathy and peripheral neuropathy. One patient had aseptic meningitis with later transverse myelitis. Three patients had multiple sites of neurological involvement. Respiratory infections preceded the neurological syndromes in four cases. Antibiotic therapy did not appear to alter the course of the disease. All patients had a favourable outcome.

  12. [Clinical score to rule out pneumonia due to Mycoplasma pneumoniae].

    PubMed

    Rodríguez de Ita, J; Torres-Quintanilla, A; Paláu-Dávila, L; Silva-Gburek, J C; Ortiz de Elguea-Lizarraga, J; Chávez Caraza, K L; Santos-Guzman, J

    2014-10-01

    The gold standard for the diagnosis of pneumonia secondary to Mycoplasma pneumoniae is the serial measurement of IgM, since an isolated test for IgM has a poor sensitivity of 31.8%. A pneumonia due to Mycoplasma pneumoniae could be of clinically different origins, thus it is possible to perform a clinical score for its early diagnosis. To develop a clinical score in order to rule out a pneumoniae secondary to Mycoplasma pneumoniae. A total of 302 patients from 0 to 18 years-old, with a diagnosis of pneumonia were evaluated and divided into two groups: Mycoplasma positive and Mycoplasma negative. Using different variables in the medical records a clinical score was calculated. Of the 302 cases studied, 34 were classified as Mycoplasma positive and 268 as Mycoplasma negative. The variables relevant to the calculation of the score were age, days with fever, and days with cough, thus providing the CAF (Cough, Age, Fever) score. Ranges were assigned for each variable and points were given for each range. A value greater than or equal to 5 meant a positive score. The CAF score was applied to the 302 cases, resulting in 164 cases of Mycoplasma positive and 138 cases of Mycoplasma negative. The CAF score had a sensitivity of 85% and specificity of 49%. The CAF score had better sensitivity than other clinical diagnostic tools. With a negative predictive value of 96% it is possible to rule out a pneumonia secondary to M. pneumoniae. The study requires a prospective study to verify the usefulness of our score. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  13. Flagella stator homologs function as motors for myxobacterial gliding motility by moving in helical trajectories.

    PubMed

    Nan, Beiyan; Bandaria, Jigar N; Moghtaderi, Amirpasha; Sun, Im-Hong; Yildiz, Ahmet; Zusman, David R

    2013-04-16

    Many bacterial species use gliding motility in natural habitats because external flagella function poorly on hard surfaces. However, the mechanism(s) of gliding remain elusive because surface motility structures are not apparent. Here, we characterized the dynamics of the Myxococcus xanthus gliding motor protein AglR, a homolog of the Escherichia coli flagella stator protein MotA. We observed that AglR decorated a helical structure, and the AglR helices rotated when cells were suspended in liquid or when cells moved on agar surfaces. With photoactivatable localization microscopy, we found that single molecules of AglR, unlike MotA/MotB, can move laterally within the membrane in helical trajectories. AglR slowed down transiently at gliding surfaces, accumulating in clusters. Our work shows that the untethered gliding motors of M. xanthus, by moving within the membrane, can transform helical motion into linear driving forces that push against the surface.

  14. Biomechanical measures of knee joint mobilization

    PubMed Central

    Silvernail, Jason L; Gill, Norman W; Teyhen, Deydre S; Allison, Stephen C

    2011-01-01

    Background and purpose The purpose of this study was to quantify the biomechanical properties of specific manual therapy techniques in patients with symptomatic knee osteoarthritis. Methods Twenty subjects (7 female/13 male, age 54±8 years, ht 1·7±0·1 m, wt 94·2±21·8 kg) participated in this study. One physical therapist delivered joint mobilizations (tibiofemoral extension and flexion; patellofemoral medial–lateral and inferior glide) at two grades (Maitland’s grade III and grade IV). A capacitance-based pressure mat was used to capture biomechanical characteristics of force and frequency during 2 trials of 15 second mobilizations. Statistical analysis included intraclass correlation coefficient (ICC3,1) for intrarater reliability and 2×4 repeated measures analyses of variance and post-hoc comparison tests. Results Force (Newtons) measurements (mean, max.) for grade III were: extension 45, 74; flexion 39, 61; medial–lateral glide 20, 34; inferior glide 16, 27. Force (Newtons) measurements (mean, max.) for grade IV were: extension 57, 76; flexion 47, 68; medial–lateral glide 23, 36; inferior glide 18, 35. Frequency (Hz) measurements were between 0·9 and 1·2 for grade III, and between 2·1 and 2·4 for grade IV. ICCs were above 0·90 for almost all measures. Discussion and conclusion Maximum force measures were between the ranges reported for cervical and lumbar mobilization at similar grades. Mean force measures were greater at grade IV than III. Oscillation frequency and peak-to-peak amplitude measures were consistent with the grade performed (i.e. greater frequency at grade IV, greater peak-to-peak amplitude at grade III). Intrarater reliability for force, peak-to-peak amplitude and oscillation frequency for knee joint mobilizations was excellent. PMID:22851879

  15. Sequence homologies between Mycoplasma and Chlamydia spp. lead to false-positive results in chlamydial cell cultures tested for mycoplasma contamination with a commercial PCR assay.

    PubMed

    Maass, Viola; Kern, Jan Marco; Poeckl, Matthias; Maass, Matthias

    2011-10-01

    Mycoplasma contamination is a frequent problem in chlamydial cell culture. After obtaining contradictory contamination results, we compared three commercial PCR kits for mycoplasma detection. One kit signaled contamination in mycoplasma-free Chlamydia pneumoniae cultures. Sequencing of cloned PCR products revealed primer homology with the chlamydial genome as the basis of this false-positive result.

  16. Effect of a Mycoplasma hominis-like Mycoplasma on the infection of HEp-2 cells by the TW-183 strain of Chlamydia pneumoniae.

    PubMed

    Castilla, E A; Wadowsky, R M

    2000-02-01

    We isolated a Mycoplasma hominis-like mycoplasma from a stock culture of Chlamydia pneumoniae TW-183 obtained from the American Type Culture Collection and eradicated the contaminant by treating the stock suspension with a nonionic detergent, Igepal CA-630. The M. hominis-like mycoplasma neither inhibits nor enhances the infectivity of C. pneumoniae for HEp-2 cells.

  17. [Decontamination of continual cell lines spontaneously infected with mycoplasmas].

    PubMed

    Machatková, M; Jurmanová, K; Snejdar, V

    1986-07-01

    The continual cell lines of bovine kidneys MDBK and AUBEK, and porcine kidneys RPD and IBRS, spontaneously infected with Mycoplasma arginini and Acholeplasma laidlawii, were decontaminated by the method of selective elimination. Two elimination procedures were modified to be used for the decontamination: one based on the reduction of infection by the light treatment of the cultures, the other based on the selection of mycoplasma-free cell population through cell clonation. On the basis of a long-continued control of the cell clones a methodical procedure of the preparation of mycoplasma-free cell lines was worked out.

  18. The role of Mycoplasma and Ureaplasma in adverse pregnancy outcomes.

    PubMed

    Murtha, Amy P; Edwards, James M

    2014-12-01

    Genital mycoplasmas are frequently found in the vaginal flora across socioeconomic and ethnic groups and have been demonstrated to be involved in adverse perinatal outcomes. Both Mycoplasma and Ureaplasma spp cause inflammation potentially leading to spontaneous preterm birth and PPROM as well as postdelivery infectious complications and neonatal infections. Herein we have provided an overview of the existing literature and supportive evidence for genital mycoplasma's role in perinatal complications. Future research will need to focus on clearly delineating the species, allowing for discrimination of their effects.

  19. Attachment of killed Mycoplasma gallisepticum cells and membranes to erythrocytes

    SciTech Connect

    Banai, M.; Kahane, I.; Feldner, J.; Razin, S.

    1981-11-01

    To correlate viability with attachment capacity, Mycoplasma gallisepticum cells harvested at different growth phases and treated by various agents were tested for their capacity to attach to human erythrocytes. The results show that viability per se is not essential for M. gallisepticum attachment to erythrocytes, as cells killed by ultraviolet irradiation and membranes isolated by lysing M. gallisepticum cells by various means retained attachment capacity. However, treatment of the mycoplasmas by protein-denaturing agents, such as heart, glutaraldehyde, or prolonged exposure to low pH, drastically affected or even abolished attachment, supporting the protein nature of the mycoplasma membrane components responsible for specific binding to the sialoglycoprotein receptors on the erythrocytes.

  20. Catalase Enhances Growth and Biofilm Production of Mycoplasma pneumoniae

    PubMed Central

    Simmons, Warren L.; Dybvig, Kevin

    2015-01-01

    Mycoplasma pneumoniae causes chronic respiratory disease in humans. Factors thought to be important for colonization include the ability of the mycoplasma to form a biofilm on epithelial surfaces and the production of hydrogen peroxide to damage host tissue. Almost all of the mycoplasmas, including M. pneumoniae, lack superoxide dismutase and catalase and a balance should exist between peroxide production and growth. We show here that the addition of catalase to cultures enhanced the formation of biofilms and altered the structure. The incorporation of catalase in agar increased the number of colony-forming units detected and hence could improve the clinical diagnosis of mycoplasmal diseases. PMID:25894997

  1. Mycoplasma hominis necrotizing pleuropneumonia in a previously healthy adolescent

    PubMed Central

    2010-01-01

    Background Mycoplasma hominis is a fastidious micro-organism causing systemic infections in the neonate and genital infections in the adult. It can also be the cause of serious extra-genital infections, mainly in immunosuppressed or predisposed subjects. Case Presentation We describe a case of severe pneumonia and pericarditis due to Mycoplasma hominis in a previously healthy adolescent who did not respond to initial therapy. Conclusions Mycoplasma hominis could be an underestimated cause of severe pneumonia in immunocompetent patients and should be particularly suspected in those not responding to standard therapy. PMID:21106079

  2. COLONIAL GROWTH OF MYCOPLASMA GALLISEPTICUM OBSERVED WITH THE ELECTRON MICROSCOPE

    PubMed Central

    Shifrine, Moshe; Pangborn, Jack; Adler, Henry E.

    1962-01-01

    Shifrine, Moshe (University of California, Davis), Jack Pangborn, and Henry E. Adler. Colonial growth of Mycoplasma gallisepticum observed with the electron microscope. J. Bacteriol. 83:187–192. 1962.—Mycoplasma gallisepticum strain S6 was grown on collodion film on solid medium. Samples were removed every few hours, fixed, washed, shadowed, and observed with the electron microscope. Three distinct forms of growth were observed: elementary cells (hexagonally shaped), platycytes, and exoblasts. A tentative mode of growth was postulated. The significance of the angular morphology to the relation between mycoplasmas and L-forms of bacteria is discussed. Images PMID:13911868

  3. Natural glide slab avalanches, Glacier National Park, USA: A unique hazard and forecasting challenge

    USGS Publications Warehouse

    Reardon, Blase; Fagre, Daniel B.; Dundas, Mark; Lundy, Chris

    2006-01-01

    In a museum of avalanche phenomena, glide cracks and glide avalanches might be housed in the “strange but true” section. These oddities are uncommon in most snow climates and tend to be isolated to specific terrain features such as bedrock slabs. Many glide cracks never result in avalanches, and when they do, the wide range of time between crack formation and slab failure makes them highly unpredictable. Despite their relative rarity, glide cracks and glide avalanches pose a regular threat and complex forecasting challenge during the annual spring opening of the Going-to-the-Sun Road in Glacier National Park, U.S.A. During the 2006 season, a series of unusual glide cracks delayed snow removal operations by over a week and provided a unique opportunity to record detailed observations of glide avalanches and characterize their occurrence and associated weather conditions. Field observations were from snowpits, crown profiles and where possible, measurements of slab thickness, bed surface slope angle, substrate and other physical characteristics. Weather data were recorded at one SNOTEL site and two automated stations located from 0.6-10 km of observed glide slab avalanches. Nearly half (43%) of the 35 glide slab avalanches recorded were Class D2-2.5, with 15% Class D3-D3.5. The time between glide crack opening and failure ranged from 2 days to over six weeks, and the avalanches occurred in cycles associated with loss of snow water equivalent and spikes in temperature and radiation. We conclude with suggest ions for further study.

  4. Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation.

    PubMed

    Cattani, Amanda Malvessi; Siqueira, Franciele Maboni; Guedes, Rafael Lucas Muniz; Schrank, Irene Silveira

    2016-01-01

    Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5' upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile.

  5. Mycoplasma genitalium: An emerging sexually transmitted pathogen

    PubMed Central

    Sethi, Sunil; Singh, Gagandeep; Samanta, Palash; Sharma, Meera

    2012-01-01

    Mycoplasma genitalium is a member of genital mycoplasmas, which is emerging as an important causative agent of sexually transmitted infections both in males and females. The advent of polymerase chain reaction and other molecular methods have made studies on M. genitalium more feasible, which is otherwise a difficult organism to isolate. Besides Chlamydia trachomatis, M. genitalium is now an important and established cause of non gonococcal urethritis (NGU) in men, more so in persistent and recurrent NGU. Multiple studies have also shown a positive association of M. genitalium with mucopurulent cervicitis and vaginal discharge in females as well. The evidences for M. genitalium pelvic inflammatory diseases and infertility are quite convincing and indicate that this organism has potential to cause ascending infection. Lack of clear association with M. genitalium has been reported for bacterial vaginosis and adverse pregnancy outcomes. Diagnosis of M. genitalium infections is performed exclusively using nucleic acid amplification tests (NAATs), owing to poor or slow growth of bacterium in culture. Although there are no guidelines available regarding treatment, macrolide group of antimicrobials appear to be more effective than tetracyclines. The present review provides an overview of the epidemiology, pathogenesis, clinical presentation and management of sexually transmitted infections due to M. genitalium. PMID:23391789

  6. Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation

    PubMed Central

    Cattani, Amanda Malvessi; Siqueira, Franciele Maboni; Guedes, Rafael Lucas Muniz; Schrank, Irene Silveira

    2016-01-01

    Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5’ upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile. PMID:28005945

  7. Collective behavior of minus-ended motors in mitotic microtubule asters gliding toward DNA

    NASA Astrophysics Data System (ADS)

    Athale, Chaitanya A.; Dinarina, Ana; Nedelec, Francois; Karsenti, Eric

    2014-02-01

    Microtubules (MTs) nucleated by centrosomes form star-shaped structures referred to as asters. Aster motility and dynamics is vital for genome stability, cell division, polarization and differentiation. Asters move either toward the cell center or away from it. Here, we focus on the centering mechanism in a membrane independent system of Xenopus cytoplasmic egg extracts. Using live microscopy and single particle tracking, we find that asters move toward chromatinized DNA structures. The velocity and directionality profiles suggest a random-walk with drift directed toward DNA. We have developed a theoretical model that can explain this movement as a result of a gradient of MT length dynamics and MT gliding on immobilized dynein motors. In simulations, the antagonistic action of the motor species on the radial array of MTs leads to a tug-of-war purely due to geometric considerations and aster motility resembles a directed random-walk. Additionally, our model predicts that aster velocities do not change greatly with varying initial distance from DNA. The movement of asymmetric asters becomes increasingly super-diffusive with increasing motor density, but for symmetric asters it becomes less super-diffusive. The transition of symmetric asters from superdiffusive to diffusive mobility is the result of number fluctuations in bound motors in the tug-of-war. Overall, our model is in good agreement with experimental data in Xenopus cytoplasmic extracts and predicts novel features of the collective effects of motor-MT interactions.

  8. Collective behavior of minus-ended motors in mitotic microtubule asters gliding toward DNA.

    PubMed

    Athale, Chaitanya A; Dinarina, Ana; Nedelec, Francois; Karsenti, Eric

    2014-02-01

    Microtubules (MTs) nucleated by centrosomes form star-shaped structures referred to as asters. Aster motility and dynamics is vital for genome stability, cell division, polarization and differentiation. Asters move either toward the cell center or away from it. Here, we focus on the centering mechanism in a membrane independent system of Xenopus cytoplasmic egg extracts. Using live microscopy and single particle tracking, we find that asters move toward chromatinized DNA structures. The velocity and directionality profiles suggest a random-walk with drift directed toward DNA. We have developed a theoretical model that can explain this movement as a result of a gradient of MT length dynamics and MT gliding on immobilized dynein motors. In simulations, the antagonistic action of the motor species on the radial array of MTs leads to a tug-of-war purely due to geometric considerations and aster motility resembles a directed random-walk. Additionally, our model predicts that aster velocities do not change greatly with varying initial distance from DNA. The movement of asymmetric asters becomes increasingly super-diffusive with increasing motor density, but for symmetric asters it becomes less super-diffusive. The transition of symmetric asters from superdiffusive to diffusive mobility is the result of number fluctuations in bound motors in the tug-of-war. Overall, our model is in good agreement with experimental data in Xenopus cytoplasmic extracts and predicts novel features of the collective effects of motor-MT interactions.

  9. Frequency of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis and Ureaplasma species in cervical samples.

    PubMed

    Rodrigues, M M; Fernandes, P Á; Haddad, J P; Paiva, M C; Souza, M Do Carmo M; Andrade, T C A; Fernandes, A P

    2011-01-01

    We investigated the relative frequencies of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis and Ureaplasma sp. in cervical samples. PCR analyses were performed in ectocervical and endocervical samples from 224 patients attending public health services in Belo Horizonte and Contagem, Minas Gerais Brazil. A high prevalence of colonisation of the cervix (6.3% for C. trachomatis, 4.0% for N. gonorrhoeae, 0.9% for M. genitalium, 21.9% for M. hominis, 38.4% for Ureaplasma sp.) was demonstrated not only for pathogens classically associated to cervicitis (C. trachomatis and N. gonorrhoeae), but also for M. hominis and Ureaplasma sp. These findings may be useful to guide more adequate diagnosis to interrupt transmission and to avoid negative impacts on the female reproductive tract.

  10. Characteristics of a new sterol-nonrequiring Mycoplasma.

    PubMed

    Tully, J G; Razin, S

    1969-06-01

    Two Mycoplasma strains recovered from tissue culture environments were found to grow in complex media devoid of serum or serum fractions containing cholesterol and in a cholesterol-free synthetic medium. Neither strain was capable of synthesizing pigmented carotenoids, although these compounds are present in, and characteristic of, other sterol-nonrequiring mycoplasmas. Serological tests and an analysis of their cell protein patterns obtained by gel electrophoresis indicated that the isolates were similar to each other but distinct from other sterol-nonrequiring serotypes, Mycoplasma laidlawii and M. granularum, as well as from sterol-requiring species. The existence of Mycoplasma other than M. laidlawii and M. granularum without sterol requirements suggested the need for some taxonomic changes in this group of organisms.

  11. Genome Sequence of Mycoplasma hyorhinis Strain DBS 1050.

    PubMed

    Dabrazhynetskaya, Alena; Soika, Valerii; Volokhov, Dmitriy; Simonyan, Vahan; Chizhikov, Vladimir

    2014-03-06

    Mycoplasma hyorhinis is known as one of the most prevalent contaminants of mammalian cell and tissue cultures worldwide. Here, we present the complete genome sequence of the fastidious M. hyorhinis strain DBS 1050.

  12. Mycoplasma hominis Induces Mediastinitis after a Tonsillar Abscess

    PubMed Central

    Grancini, Anna; Colosimo, Manuela; Restelli, Antonella; Colombo, Rosaria; Maraschini, Anna; Pozzi, Cristina; Breda, Giuseppe; Protti, Alessandro; Arghittu, Milena; Maiavacca, Rita

    2016-01-01

    Mycoplasma hominis is commonly involved in genitourinary tract infections. We report a 59-year-old man who developed a M. hominis-associated mediastinitis following acute tonsillar infection. PMID:27957362

  13. Mycoplasma pneumoniae induces cytotoxic activity in guinea pig bronchoalveolar cells

    SciTech Connect

    Kist, M.; Koester, H.; Bredt, W.

    1985-06-01

    Precultured guinea pig alveolar macrophages (AM) and freshly harvested alveolar cells (FHAC) activated by interaction with Mycoplasma pneumoniae were cytotoxic for xenogeneic /sup 75/selenomethionine-labeled tumor target cells. Phagocytosis of whole opsonized or nonopsonized M. pneumoniae cells was more effective in eliciting cytotoxicity than uptake of sonicated microorganisms. The addition of living mycoplasma cells to the assay system enhanced the cytotoxic effect considerably. Target cells were significantly more susceptible to the cytotoxic action of phagocytes if they were coated with mycoplasma antigen or cocultured together with M. pneumoniae. The activation of the phagocytes could be inhibited by 2-deoxy-D-glucose but not by antimicrobial substances suppressing mycoplasma protein synthesis. It was accompanied by /sup 51/Cr release without detectable signs of cell damage. The supernatants of activated cells were cytotoxic for approximately 24 h. Inhibition, release, and cytotoxic activity indicate the necessity of an intact metabolism of the effector cells and suggest a secretion of cytotoxic substances.

  14. Urinary tract infections due to Mycoplasma canis in dogs.

    PubMed

    Ulgen, M; Cetin, C; Sentürk, S; Ozel, A E; Ozdemir, U

    2006-09-01

    Urine samples were obtained from 100 dogs with symptoms of lower urinary tract disease by cystocentesis and were examined for mycoplasmas. Urinalysis, haematological and biochemical analyses were also performed. Bacteria were isolated from urine in 41 of 100 dogs; Mycoplasma canis was isolated from four of 100 (4%) urine samples and three were pure culture. Selective mycoplasma media were used for isolation. In growth inhibition test, propagation of the four M. canis isolates was inhibited by their specific hyperimmune sera and there was no cross reactivity between isolates and hyperimmune sera of other mycoplasmas. Dogs in which M. canis was isolated were azotemic. All dogs were treated with enrofloxacin, furosemide, and supportive therapy (fluid therapy, ascorbic acid). In all animals, clinical improvements were observed after treatment.

  15. Asset and prime - Gliding re-entry test vehicles

    NASA Astrophysics Data System (ADS)

    Powell, J. W.; Hengeveld, E.

    1983-08-01

    The history of the USAF development programs for winged controlled-reentry vehicles based on a dynamic-gliding principle, ASSET (1957-1965) and PRIME (1964-1967), is recounted. The ASSET program, developed from the initial Dyna-Soar project, comprised three aerothermodynamic-structural vehicles and three aerothermoelastic vehicles, all utilizing exotic refractory metal structures partially coated with silicon-boron, zirconia-ceramic nose caps, and LV-2C Thor launchers. The three PRIME SV-5D vehicles employed elastomeric-blanket ablative heat shields and molded carbon-phenolic-composite nose caps and were launched by SLV-3 Atlas rockets. It is noted that these projects, although successful, did not lead directly to the production of lifting-body or winged reentry vehicles, but rather provided data useful in the later Shuttle development program.

  16. Leaping shampoo glides on a lubricating air layer.

    PubMed

    Lee, S; Li, E Q; Marston, J O; Bonito, A; Thoroddsen, S T

    2013-06-01

    When a stream of shampoo is fed onto a pool in one's hand, a jet can leap sideways or rebound from the liquid surface in an intriguing phenomenon known as the Kaye effect. Earlier studies have debated whether non-Newtonian effects are the underlying cause of this phenomenon, making the jet glide on top of a shear-thinning liquid layer, or whether an entrained air layer is responsible. Herein we show unambiguously that the jet slides on a lubricating air layer. We identify this layer by looking through the pool liquid and observing its rupture into fine bubbles. The resulting microbubble sizes suggest this air layer is of submicron thickness. This thickness estimate is also supported by the tangential deceleration of the jet during the rebounding.

  17. Numerical Investigation of Swimmer's Gliding Stage with 6-DOF Movement.

    PubMed

    Li, Tianzeng; Cai, Wenhao; Zhan, Jiemin

    2017-01-01

    The purpose of this study is to analyze the motion status of swimmers during their gliding stage using a numerical simulation method. This simulation strategy is conducted by solving the 3D incompressible Navier-Stokes equations using the Realizable k-ε turbulence closure equations in combination with the Six Degrees of Freedom (6-DOF) method. The uneven mass distribution of a swimmer and the roughness of the surface of the body are taken into consideration. The hydrodynamic characteristics and movement characteristics of the swimmers at different launch speeds were analyzed. The calculated results suggest that an optimal instant for starting propulsive movement is when the velocity of the swimmer decreases by 1.75 m/s to 2.0 m/s from an initial horizontal velocity of 3.1 m/s to 3.5 m/s.

  18. Employment of hypersonic glide vehicles: Proposed criteria for use

    SciTech Connect

    Olguin, Abel

    2014-07-01

    Hypersonic Glide Vehicles (HGVs) are a type of reentry vehicle that couples the high speed of ballistic missiles with the maneuverability of aircraft. The HGV has been in development since the 1970s, and its technology falls under the category of Conventional Prompt Global Strike (CPGS) weapons. As noted by James M. Acton, a senior associate in the Nuclear Policy Program at the Carnegie Endowment, CPGS is a “missile in search of a mission.” With the introduction of any significant new military capability, a doctrine for use—including specifics regarding how, when and where it would be used, as well as tactics, training and procedures—must be clearly defined and understood by policy makers, military commanders, and planners. In this paper, benefits and limitations of the HGV are presented. Proposed criteria and four scenarios illustrate a possible method for assessing when to use an HGV.

  19. Leaping shampoo glides on a lubricating air layer

    NASA Astrophysics Data System (ADS)

    Lee, S.; Li, E. Q.; Marston, J. O.; Bonito, A.; Thoroddsen, S. T.

    2013-06-01

    When a stream of shampoo is fed onto a pool in one's hand, a jet can leap sideways or rebound from the liquid surface in an intriguing phenomenon known as the Kaye effect. Earlier studies have debated whether non-Newtonian effects are the underlying cause of this phenomenon, making the jet glide on top of a shear-thinning liquid layer, or whether an entrained air layer is responsible. Herein we show unambiguously that the jet slides on a lubricating air layer. We identify this layer by looking through the pool liquid and observing its rupture into fine bubbles. The resulting microbubble sizes suggest this air layer is of submicron thickness. This thickness estimate is also supported by the tangential deceleration of the jet during the rebounding.

  20. Water treatment by the AC gliding arc air plasma

    NASA Astrophysics Data System (ADS)

    Gharagozalian, Mehrnaz; Dorranian, Davoud; Ghoranneviss, Mahmood

    2017-06-01

    In this study, the effects of gliding arc (G Arc) plasma system on the treatment of water have been investigated experimentally. An AC power supply of 15 kV potential difference at 50 Hz frequency was employed to generate plasma. Plasma density and temperature were measured using spectroscopic method. The water was contaminated with staphylococcus aureus (Gram-positive) and salmonella bacteria (Gram-negative), and Penicillium (mold fungus) individually. pH, hydrogen peroxide, and nitride contents of treated water were measured after plasma treatment. Decontamination of treated water was determined using colony counting method. Results indicate that G Arc plasma is a powerful and green tool to decontaminate water without producing any byproducts.

  1. Degradation of tetrafluoroethane using three-phase gliding arc plasma

    NASA Astrophysics Data System (ADS)

    Pacheco, J.; García, M.; Pacheco, M.; Valdivia, R.; Rivera, C.; Garduño, M.

    2012-06-01

    The use of many chlorofluorocarbons (CFC's) has negatively impacted the ozone layer. The Montreal Protocol was implemented, as a temporary solution for this problem by replacing CFC's by hydrofluorocarbons (HFC's). These kinds of gases have the propriety to be free of chlorine. However, in a next future, the Montreal Protocol also considers the replacement of HFC's because they have a high global warming potential when they enter in contact with the atmosphere. One of the methods to remove those compounds is the gliding arc plasma because it presents some advantages. The inlet system works near the atmospheric pressure and has a transition region from plasma at thermodynamic local partial equilibrium to non-thermal plasma; allowing high gas and electronic temperatures. Results present a promissory possibility to be scaled and to give an industrial service.

  2. Gliding Motility Revisited: How Do the Myxobacteria Move without Flagella?

    PubMed Central

    Mauriello, Emilia M. F.; Mignot, Tâm; Yang, Zhaomin; Zusman, David R.

    2010-01-01

    Summary: In bacteria, motility is important for a wide variety of biological functions such as virulence, fruiting body formation, and biofilm formation. While most bacteria move by using specialized appendages, usually external or periplasmic flagella, some bacteria use other mechanisms for their movements that are less well characterized. These mechanisms do not always exhibit obvious motility structures. Myxococcus xanthus is a motile bacterium that does not produce flagella but glides slowly over solid surfaces. How M. xanthus moves has remained a puzzle that has challenged microbiologists for over 50 years. Fortunately, recent advances in the analysis of motility mutants, bioinformatics, and protein localization have revealed likely mechanisms for the two M. xanthus motility systems. These results are summarized in this review. PMID:20508248

  3. Glide planes symmetry in the organization of some sulfide structures

    NASA Astrophysics Data System (ADS)

    Borisov, S. V.; Magarill, S. A.; Pervukhina, N. V.

    2016-03-01

    The role of glide planes in the organization of structures is shown based on a crystallographic analysis of the monoclinic structures of TlAs3S5 and Tl2(As,Sb)3S13 sulfides. In the first structure, cations and anions form systems (with identical geometries) of two face-centered sublattices, linked by the c plane, with the effect of unified "two-dimensional" (2D) ordering. The second structure, exhibiting signs of order-disorder (OD) type, is interpreted as a superposition of two noncentrosymmetric components with independent cation and anion sublattices, which, however, also form a regular 2D order due to the n plane. The stabilizing role of Tl cations in the geometry of cation matrices is indicated.

  4. Water treatment by the AC gliding arc air plasma

    NASA Astrophysics Data System (ADS)

    Gharagozalian, Mehrnaz; Dorranian, Davoud; Ghoranneviss, Mahmood

    2017-09-01

    In this study, the effects of gliding arc (G Arc) plasma system on the treatment of water have been investigated experimentally. An AC power supply of 15 kV potential difference at 50 Hz frequency was employed to generate plasma. Plasma density and temperature were measured using spectroscopic method. The water was contaminated with staphylococcus aureus (Gram-positive) and salmonella bacteria (Gram-negative), and Penicillium (mold fungus) individually. pH, hydrogen peroxide, and nitride contents of treated water were measured after plasma treatment. Decontamination of treated water was determined using colony counting method. Results indicate that G Arc plasma is a powerful and green tool to decontaminate water without producing any byproducts.

  5. Susceptibilities of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum strains to antimicrobial agents in vitro.

    PubMed

    ter Laak, E A; Noordergraaf, J H; Verschure, M H

    1993-02-01

    The purpose of this study was to determine the susceptibility of various strains of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum, which are prevalent causes of pneumonia in calves, to 16 antimicrobial agents in vitro. The MICs of the antimicrobial agents were determined by a serial broth dilution method for 16 field strains and the type strain of M. bovis, for 19 field strains and the type strain of M. dispar, and for 17 field strains of U. diversum. Final MICs for M. bovis and M. dispar were read after 7 days and final MICs for U. diversum after 1 to 2 days. All strains tested were susceptible to tylosin, kitasamycin, and tiamulin but were resistant to nifuroquine and streptomycin. Most strains of U. diversum were intermediately susceptible to oxytetracycline but fully susceptible to chlortetracycline; most strains of M. bovis and M. dispar, however, were resistant to both agents. Strains of M. dispar and U. diversum were susceptible to doxycycline and minocycline, but strains of M. bovis were only intermediately susceptible. Susceptibility or resistance to chloramphenicol, spiramycin, spectinomycin, lincomycin, or enrofloxacin depended on the species but was not equal for the three species. The type strains of M. bovis and M. dispar were more susceptible to various antimicrobial agents, including tetracyclines, than the field strains. This finding might indicate that M. bovis and M. dispar strains are becoming resistant to these agents. Antimicrobial agents that are effective in vitro against all three mycoplasma species can be considered for treating mycoplasma infections in pneumonic calves. Therefore, tylosin, kitasamycin, and tiamulin may be preferred over oxytetracycline and chlortetracycline.

  6. Susceptibilities of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum strains to antimicrobial agents in vitro.

    PubMed Central

    ter Laak, E A; Noordergraaf, J H; Verschure, M H

    1993-01-01

    The purpose of this study was to determine the susceptibility of various strains of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum, which are prevalent causes of pneumonia in calves, to 16 antimicrobial agents in vitro. The MICs of the antimicrobial agents were determined by a serial broth dilution method for 16 field strains and the type strain of M. bovis, for 19 field strains and the type strain of M. dispar, and for 17 field strains of U. diversum. Final MICs for M. bovis and M. dispar were read after 7 days and final MICs for U. diversum after 1 to 2 days. All strains tested were susceptible to tylosin, kitasamycin, and tiamulin but were resistant to nifuroquine and streptomycin. Most strains of U. diversum were intermediately susceptible to oxytetracycline but fully susceptible to chlortetracycline; most strains of M. bovis and M. dispar, however, were resistant to both agents. Strains of M. dispar and U. diversum were susceptible to doxycycline and minocycline, but strains of M. bovis were only intermediately susceptible. Susceptibility or resistance to chloramphenicol, spiramycin, spectinomycin, lincomycin, or enrofloxacin depended on the species but was not equal for the three species. The type strains of M. bovis and M. dispar were more susceptible to various antimicrobial agents, including tetracyclines, than the field strains. This finding might indicate that M. bovis and M. dispar strains are becoming resistant to these agents. Antimicrobial agents that are effective in vitro against all three mycoplasma species can be considered for treating mycoplasma infections in pneumonic calves. Therefore, tylosin, kitasamycin, and tiamulin may be preferred over oxytetracycline and chlortetracycline. PMID:8452363

  7. Functional characterization of the RuvB homologs from Mycoplasma pneumoniae and Mycoplasma genitalium.

    PubMed

    Estevão, Silvia; Sluijter, Marcel; Hartwig, Nico G; van Rossum, Annemarie M C; Vink, Cornelis

    2011-12-01

    Homologous recombination between repeated DNA elements in the genomes of Mycoplasma species has been hypothesized to be a crucial causal factor in sequence variation of antigenic proteins at the bacterial surface. To investigate this notion, studies were initiated to identify and characterize the proteins that form part of the homologous DNA recombination machinery in Mycoplasma pneumoniae as well as Mycoplasma genitalium. Among the most likely participants of this machinery are homologs of the Holliday junction migration motor protein RuvB. In both M. pneumoniae and M. genitalium, genes have been identified that have the capacity to encode RuvB homologs (MPN536 and MG359, respectively). Here, the characteristics of the MPN536- and MG359-encoded proteins (the RuvB proteins from M. pneumoniae strain FH [RuvB(FH)] and M. genitalium [RuvB(Mge)], respectively) are described. Both RuvB(FH) and RuvB(Mge) were found to have ATPase activity and to bind DNA. In addition, both proteins displayed divalent cation- and ATP-dependent DNA helicase activity on partially double-stranded DNA substrates. The helicase activity of RuvB(Mge), however, was significantly lower than that of RuvB(FH). Interestingly, we found RuvB(FH) to be expressed exclusively by subtype 2 strains of M. pneumoniae. In strains belonging to the other major subtype (subtype 1), a version of the protein is expressed (the RuvB protein from M. pneumoniae strain M129 [RuvB(M129)]) that differs from RuvB(FH) in a single amino acid residue (at position 140). In contrast to RuvB(FH), RuvB(M129) displayed only marginal levels of DNA-unwinding activity. These results demonstrate that M. pneumoniae strains (as well as closely related Mycoplasma spp.) can differ significantly in the function of components of their DNA recombination and repair machinery.

  8. GlideScope Use improves intubation success rates: an observational study using propensity score matching.

    PubMed

    Ibinson, James W; Ezaru, Catalin S; Cormican, Daniel S; Mangione, Michael P

    2014-01-01

    Rigid video laryngoscopes are popular alternatives to direct laryngoscopy for intubation, but further large scale prospective studies comparing these devices to direct laryngoscopy in routine anesthesiology practice are needed. We hypothesized that the first pass success rate with one particular video laryngoscope, the GlideScope, would be higher than the success rate with direct laryngoscopy. 3831 total intubation attempts were tracked in an observational study comparing first-pass success rate using a Macintosh or Miller-style laryngoscope with the GlideScope. Propensity scoring was then used to select 626 subjects matched between the two groups based on their morphologic traits. Comparing the GlideScope and direct laryngoscopy groups suggested that intubation would be more difficult in the GlideScope group based on the Mallampati class, cervical range of motion, mouth opening, dentition, weight, and past intubation history. Thus, a propensity score based on these factors was used to balance the groups into two 313 patient cohorts. Direct laryngoscopy was successful in 80.8% on the first-pass intubation attempt, while the GlideScope was successful in 93.6% (p <0.001; risk difference of 0.128 with a 95% CI of 0.0771 - 0.181). A greater first-attempt success rate was found when using the GlideScope versus direct laryngoscopy. In addition, the GlideScope was found to be 99% successful for intubation after initial failure of direct laryngoscopy, helping to reduce the incidence of failed intubation.

  9. Selective inhibition of DNA amplification in nonadhering Mycoplasma pneumoniae cultures

    SciTech Connect

    Zigangirova, N.A.; Solov`eva, S.V.; Rakovskaya, I.V.

    1995-08-01

    Inhibition of amplification of various genome regions of Mycoplasma pneumoniae was observed in the polymerase chain reaction, and was dependent on cultivation conditions. A protein stably associated with DNA is responsible for the inhibitory effect. It is assumed that when the protein selectively associates with separate DNA regions, it can inhibit genes encoding pathogenicity factors, thus promoting mycoplasma transformation into persistent variants. 16 refs., 2 figs.

  10. Mycoplasma insons sp. nov., a twisted mycoplasma from green iguanas (Iguana iguana).

    PubMed

    May, Meghan; Ortiz, G Javier; Wendland, Lori D; Rotstein, David S; Relich, Ryan F; Balish, Mitchell F; Brown, Daniel R

    2007-09-01

    Mycoplasma insons sp. nov., first cultured from the choanae and tracheae of healthy green iguanas (Iguana iguana) from El Salvador, was readily distinguished from all previously described mollicutes and assigned to the Mycoplasma fastidiosum phylogenetic cluster by 16S rRNA gene sequence comparisons. Growth inhibition assays distinguished the isolates serologically from the other two members of that cluster. Many M. insons cells exhibit a remarkable twisted rod morphology despite lacking a cell wall. The organism is nonmotile, produces acid from glucose, but does not hydrolyze arginine, esculin, or urea. Mycoplasma insons 16S rRNA gene was also detected by PCR in packed blood cells from culture-negative iguanas. The type strain I17P1(T) has been deposited with the Mollicutes Collection at Purdue University and with the American Type Culture Collection (ATCC BAA-1435) in the USA. A limited number of cultures generated by the authors have also been deposited with the Culture Collection, University of Göteborg, in Sweden (CCUG 53461).

  11. Complexity of the Mycoplasma fermentans M64 Genome and Metabolic Essentiality and Diversity among Mycoplasmas

    PubMed Central

    Chan, Huang-I; Liu, Yen-Ming; Wu, Keh-Ming; Shu, Hung-Yu; Tsai, Shih-Feng; Hsiao, Kwang-Jen; Hu, Wensi S.; Ng, Wailap Victor

    2012-01-01

    Recently, the genomes of two Mycoplasma fermentans strains, namely M64 and JER, have been completely sequenced. Gross comparison indicated that the genome of M64 is significantly bigger than the other strain and the difference is mainly contributed by the repetitive sequences including seven families of simple and complex transposable elements ranging from 973 to 23,778 bps. Analysis of these repeats resulted in the identification of a new distinct family of Integrative Conjugal Elements of M. fermentans, designated as ICEF-III. Using the concept of “reaction connectivity”, the metabolic capabilities in M. fermentans manifested by the complete and partial connected biomodules were revealed. A comparison of the reported M. pulmonis, M. arthritidis, M. genitalium, B. subtilis, and E. coli essential genes and the genes predicted from the M64 genome indicated that more than 73% of the Mycoplasmas essential genes are preserved in M. fermentans. Further examination of the highly and partly connected reactions by a novel combinatorial phylogenetic tree, metabolic network, and essential gene analysis indicated that some of the pathways (e.g. purine and pyrimidine metabolisms) with partial connected reactions may be important for the conversions of intermediate metabolites. Taken together, in light of systems and network analyses, the diversity among the Mycoplasma species was manifested on the variations of their limited metabolic abilities during evolution. PMID:22509252

  12. Detection of mycoplasma contamination in cell cultures by a mycoplasma group-specific PCR.

    PubMed Central

    van Kuppeveld, F J; Johansson, K E; Galama, J M; Kissing, J; Bölske, G; van der Logt, J T; Melchers, W J

    1994-01-01

    The suitability of a 16S rRNA-based mycoplasma group-specific PCR for the detection of mycoplasma contamination in cell cultures was investigated. A total of 104 cell cultures were tested by using microbiological culture, DNA fluorochrome staining, DNA-rRNA hybridization, and PCR techniques. A comparison of the results obtained with these techniques revealed agreement for 95 cell cultures. Discrepant results, which were interpreted as false negative or false positive on the basis of a comparison with the results obtained with other methods, were observed with nine cell cultures. The microbiological culture technique produced false-negative results for four cell cultures. The hybridization technique produced false-negative results for two cell cultures, and for one of these cell cultures the DNA staining technique also produced a false-negative result. The PCR may have produced false-positive results for one cell culture. Ambiguous results were obtained with the remaining two cell cultures. Furthermore, the presence of contaminating bacteria interfered with the interpretation of the DNA staining results for 16 cell cultures. For the same reason the hybridization signals of nine cell cultures could not be interpreted. Our results demonstrate the drawbacks of each of the detection methods and the suitability of the PCR for the detection of mycoplasmas in cell cultures. PMID:7509584

  13. Prevalence of Mycoplasma genitalium and Mycoplasma hominis in urogenital tract of Brazilian women.

    PubMed

    Campos, Guilherme Barreto; Lobão, Tássia Neves; Selis, Nathan Neves; Amorim, Aline Teixeira; Martins, Hellen Braga; Barbosa, Maysa Santos; Oliveira, Thiago Henrique Caldeira; dos Santos, Djanilson Barbosa; Figueiredo, Tiana Baqueiro; Miranda Marques, Lucas; Timenetsky, Jorge

    2015-02-14

    The role of Mycoplasma hominis and M. genitalium in urogenital tract infections remains unknown. Furthermore these mollicutes present a complex relationship with the host immune response. The role of inflammatory cytokines in infections also makes them good candidates to investigate bacterial vaginosis and mycoplasma genital infections. Therefore, the aim of this study was to detect the above-mentioned mollicutes by quantitative Polymerase Chain Reaction (qPCR) methodologies in vaginal swabs and dosage of cytokines. Vaginal swabs and peripheral blood were collected from 302 women, including healthy individuals. The molecular findings were correlated with some individual behavioral variables, clinical and demographic characteristics, presence of other important microorganisms in vaginal swabs, and levels of interleukin (IL)-1β and IL-6. M. hominis and M. genitalium were detected in 31.8% and 28.1% of samples, respectively. The qPCR results were associated with clinical signs and symptoms of the infections studied. The frequency of Trichomonas vaginalis, Gardnerella vaginalis, Neisseria gonorrhoeae and Chlamydia trachomatis was 3.0%, 21.5%, 42.4%, and 1.7% respectively. Increased levels of IL-1β were associated with the presence of M. hominis and signs and/or symptoms of the genital infection of women studied. IL-1β production was associated with the detection of M. hominis by qPCR. The sexual behavior of women studied was associated with the detection of mycoplasma and other agents of genital infections.

  14. Comparison of the illumigene Mycoplasma DNA Amplification Assay and Culture for Detection of Mycoplasma pneumoniae

    PubMed Central

    Ratliff, Amy E.; Duffy, Lynn B.

    2014-01-01

    A loop-mediated isothermal amplification (LAMP) system, the illumigene Mycoplasma DNA amplification assay (Meridian Bioscience, Inc., Cincinnati, OH) was evaluated to determine its analytical sensitivity, specificity, and clinical application in comparison to historic culture in a collection of archived respiratory specimens. The illumigene limit of detection was ≤88 CFU/reaction for 10 Mycoplasma pneumoniae reference strains. This assay correctly identified 36 M. pneumoniae reference strains and clinical isolates from various geographic origins, including both of the main subtypes. No cross-reactions were detected with other mycoplasmas, ureaplasmas, other bacterial species, viruses, yeasts, or human DNA. Among 214 respiratory specimens previously cultured for M. pneumoniae, when real-time PCR with bidirectional sequencing of the PCR products was used to resolve discrepancies, the sensitivity was 22 of 22 (100%) and the specificity was 190 of 192 (99%). This commercial LAMP assay is a useful rapid method for detecting M. pneumoniae in clinical specimens. Additional prospective clinical trials with direct comparison to culture and PCR are warranted. PMID:24430454

  15. Genomic repeats, genome plasticity and the dynamics of Mycoplasma evolution

    PubMed Central

    Rocha, Eduardo P. C.; Blanchard, Alain

    2002-01-01

    Mycoplasmas evolved by a drastic reduction in genome size, but their genomes contain numerous repeated sequences with important roles in their evolution. We have established a bioinformatic strategy to detect the major recombination hot-spots in the genomes of Mycoplasma pneumoniae, Mycoplasma genitalium, Ureaplasma urealyticum and Mycoplasma pulmonis. This allowed the identification of large numbers of potentially variable regions, as well as a comparison of the relative recombination potentials of different genomic regions. Different trends are perceptible among mycoplasmas, probably due to different functional and structural constraints. The largest potential for illegitimate recombination in M.pulmonis is found at the vsa locus and its comparison in two different strains reveals numerous changes since divergence. On the other hand, the main M.pneumoniae and M.genitalium adhesins rely on large distant repeats and, hence, homologous recombination for variation. However, the relation between the existence of repeats and antigenic variation is not necessarily straightforward, since repeats of P1 adhesin were found to be anti-correlated with epitopes recognized by patient antibodies. These different strategies have important consequences for the structures of genomes, since large distant repeats correlate well with the major chromosomal rearrangements. Probably to avoid such events, mycoplasmas strongly avoid inverse repeats, in comparison to co-oriented repeats. PMID:11972343

  16. A Mycoplasma species of Emydidae turtles in the northeastern USA.

    PubMed

    Ossiboff, Robert J; Raphael, Bonnie L; Ammazzalorso, Alyssa D; Seimon, Tracie A; Niederriter, Holly; Zarate, Brian; Newton, Alisa L; McAloose, Denise

    2015-04-01

    Mycoplasma infections can cause significant morbidity and mortality in captive and wild chelonians. As part of a health assessment of endangered bog turtles (Glyptemys muhlenbergii) in the northeastern US, choanal and cloacal swabs from these and other sympatric species, including spotted turtles (Clemmys guttata), eastern box turtles (Terrapene carolina carolina), wood turtles (Glyptemys insculpta), and common snapping turtles (Chelydra serpentina) from 10 sampling sites in the states (US) of Delaware, New Jersey, and Pennsylvania, were tested by PCR for Mycoplasma. Of 108 turtles tested, 63 (58.3%) were PCR positive for Mycoplasma including 58 of 83 bog turtles (70%), three of three (100%) eastern box turtles, and two of 11 (18%) spotted turtles; all snapping turtles (n = 7) and wood turtles (n = 4) were negative. Sequence analysis of portions of the 16S-23S intergenic spacer region and the 16S ribosomal RNA gene revealed a single, unclassified species of Mycoplasma that has been previously reported in eastern box turtles, ornate box turtles (Terrapene ornata ornata), western pond turtles (Emys marmorata), and red-eared sliders (Trachemys scripta elegans). We document a high incidence of Mycoplasma, in the absence of clinical disease, in wild emydid turtles. These findings, along with wide distribution of the identified Mycoplasma sp. across a broad geographic region, suggest this bacterium is likely a commensal inhabitant of bog turtles, and possibly other species of emydid turtles, in the northeastern US.

  17. Role of Vpma phase variation in Mycoplasma agalactiae pathogenesis

    PubMed Central

    Chopra-Dewasthaly, Rohini; Baumgartner, Martina; Gamper, Erika; Innerebner, Carmen; Zimmermann, Martina; Schilcher, Franz; Tichy, Alexander; Winter, Petra; Rosengarten, Renate; Spergser, Joachim

    2015-01-01

    Compared with other bacterial pathogens, the molecular mechanisms of mycoplasma pathogenicity are largely unknown. Several studies in the past have shown that pathogenic mycoplasmas are equipped with sophisticated genetic systems that allow them to undergo high-frequency surface antigenic variations. Although never clearly proven, these variable mycoplasma surface components are often implicated in host immune evasion and adaptation. Vpma surface lipoproteins of the ruminant pathogen Mycoplasma agalactiae are encoded on a genomic pathogenicity island–like locus and are considered as one of the well-characterized model systems of mycoplasma surface antigenic variation. The present study assesses the role of these phase-variable Vpmas in the molecular pathogenesis of M. agalactiae by testing the wild-type strain PG2 in comparison with the xer1-disrupted Vpma ‘phase-locked’ mutants in sheep infection models. The data clearly illustrate that although Xer1 recombinase is not a virulence factor of M. agalactiae and Vpma phase variation is not necessary for establishing an infection, it might critically influence the survival and persistence of the pathogen under natural field conditions, mainly due to a better capacity for dissemination and evoking systemic responses. This is the first study where mycoplasma ‘phase-locked’ mutants are tested in vivo to elucidate the role of phase variation during infection. PMID:22809092

  18. Mycoplasma Removal from Cell Culture Using Antimicrobial Photodynamic Therapy

    PubMed Central

    Hasebe, Akira; Ishikawa, Isao; Shamsul, Haque M.; Ohtani, Makoto; Segawa, Taku; Saeki, Ayumi; Tanizume, Naoho; Oouchi, Manabu; Okagami, Yoshihide; Okano, Teruo

    2013-01-01

    Abstract Objective: The objective of this research was to determine the effectiveness of antimicrobial photodynamic therapy (aPDT) in the removal of mycoplasmas from contaminated cells. Background data: Mycoplasmas often contaminate cell cultures. The cell-contaminating mycoplasmas are removed by antibiotics, but the use of antibiotics usually induces antibiotic-resistant bacteria. aPDT is expected to be a possible alternative to antibiotic treatments for suppressing infections. Materials and Methods: Mycoplasma salivarium (Ms)-infected human embryonic kidney (HEK) 293 cells were irradiated using a red light-emitting diode (LED) in the presence of methylene blue (MB) as a photosensitizer. The Ms viable count was determined using culture on agar plates or using a mycoplasma detection kit. Results: aPDT performed using red LED irradiation was effective in decreasing live Ms in the presence of MB without damaging the HEK293 cells. aPDT removed live Ms from the infected cells after washing the cells with sterilized phosphate-buffered saline (PBS) to decrease the initial number of live Ms before aPDT. Conclusions: This study suggests that aPDT could remove mycoplasmas from contaminated cells. PMID:23402393

  19. Onboard Determination of Vehicle Glide Capability for Shuttle Abort Flight Managment (SAFM)

    NASA Technical Reports Server (NTRS)

    Straube, Timothy; Jackson, Mark; Fill, Thomas; Nemeth, Scott

    2002-01-01

    When one or more main engines fail during ascent, the flight crew of the Space Shuttle must make several critical decisions and accurately perform a series of abort procedures. One of the most important decisions for many aborts is the selection ofa landing site. Several factors influence the ability to reach a landing site, including the spacecraft point of atmospheric entry, the energy state at atmospheric entry, the vehicle glide capability from that energy state, and whether one or more suitable landing sites are within the glide capability. Energy assessment is further complicated by the fact that phugoid oscillations in total energy influence glide capability. Once the glide capability is known, the crew must select the "best" site option based upon glide capability and landing site conditions and facilities. Since most of these factors cannot currently be assessed by the crew in flight, extensive planning is required prior to each mission to script a variety of procedures based upon spacecraft velocity at the point of engine failure (or failures). The results of this preflight planning are expressed in tables and diagrams on mission-specific cockpit checklists. Crew checklist procedures involve leafing through several pages of instructions and navigating a decision tree for site selection and flight procedures - all during a time critical abort situation. With the advent of the Cockpit Avionics Upgrade (CAU), the Shuttle will have increased on-board computational power to help alleviate crew workload during aborts and provide valuable situational awareness during nominal operations. One application baselined for the CAU computers is Shuttle Abort Flight Management (SAFM), whose requirements have been designed and prototyped. The SAFM application includes powered and glided flight algorithms. This paper describes the glided flight algorithm which is dispatched by SAFM to determine the vehicle glide capability and make recommendations to the crew for site

  20. Parallel glide: flow of dislocations with internal stress source/sink distribution

    PubMed Central

    Raić, Karlo T

    2008-01-01

    The unexpected glide of dislocations on a plane parallel to the film/substrate interface in ultrathin copper films, which has been called parallel glide (Balk et al 2003 Acta Metall. 51 447), is described using an analytical model. The phenomenon is observed as a problem involving inlet/outlet flow from different positions of a grain boundary into the grain channel. In this sense, parallel glide is presented as the flow of dislocations with an internal stress source/sink distribution. PMID:27877945

  1. Swine and Poultry Pathogens: the Complete Genome Sequences of Two Strains of Mycoplasma hyopneumoniae and a Strain of Mycoplasma synoviae†

    PubMed Central

    Vasconcelos, Ana Tereza R.; Ferreira, Henrique B.; Bizarro, Cristiano V.; Bonatto, Sandro L.; Carvalho, Marcos O.; Pinto, Paulo M.; Almeida, Darcy F.; Almeida, Luiz G. P.; Almeida, Rosana; Alves-Filho, Leonardo; Assunção, Enedina N.; Azevedo, Vasco A. C.; Bogo, Maurício R.; Brigido, Marcelo M.; Brocchi, Marcelo; Burity, Helio A.; Camargo, Anamaria A.; Camargo, Sandro S.; Carepo, Marta S.; Carraro, Dirce M.; de Mattos Cascardo, Júlio C.; Castro, Luiza A.; Cavalcanti, Gisele; Chemale, Gustavo; Collevatti, Rosane G.; Cunha, Cristina W.; Dallagiovanna, Bruno; Dambrós, Bibiana P.; Dellagostin, Odir A.; Falcão, Clarissa; Fantinatti-Garboggini, Fabiana; Felipe, Maria S. S.; Fiorentin, Laurimar; Franco, Gloria R.; Freitas, Nara S. A.; Frías, Diego; Grangeiro, Thalles B.; Grisard, Edmundo C.; Guimarães, Claudia T.; Hungria, Mariangela; Jardim, Sílvia N.; Krieger, Marco A.; Laurino, Jomar P.; Lima, Lucymara F. A.; Lopes, Maryellen I.; Loreto, Élgion L. S.; Madeira, Humberto M. F.; Manfio, Gilson P.; Maranhão, Andrea Q.; Martinkovics, Christyanne T.; Medeiros, Sílvia R. B.; Moreira, Miguel A. M.; Neiva, Márcia; Ramalho-Neto, Cicero E.; Nicolás, Marisa F.; Oliveira, Sergio C.; Paixão, Roger F. C.; Pedrosa, Fábio O.; Pena, Sérgio D. J.; Pereira, Maristela; Pereira-Ferrari, Lilian; Piffer, Itamar; Pinto, Luciano S.; Potrich, Deise P.; Salim, Anna C. M.; Santos, Fabrício R.; Schmitt, Renata; Schneider, Maria P. C.; Schrank, Augusto; Schrank, Irene S.; Schuck, Adriana F.; Seuanez, Hector N.; Silva, Denise W.; Silva, Rosane; Silva, Sérgio C.; Soares, Célia M. A.; Souza, Kelly R. L.; Souza, Rangel C.; Staats, Charley C.; Steffens, Maria B. R.; Teixeira, Santuza M. R.; Urmenyi, Turan P.; Vainstein, Marilene H.; Zuccherato, Luciana W.; Simpson, Andrew J. G.; Zaha, Arnaldo

    2005-01-01

    This work reports the results of analyses of three complete mycoplasma genomes, a pathogenic (7448) and a nonpathogenic (J) strain of the swine pathogen Mycoplasma hyopneumoniae and a strain of the avian pathogen Mycoplasma synoviae; the genome sizes of the three strains were 920,079 bp, 897,405 bp, and 799,476 bp, respectively. These genomes were compared with other sequenced mycoplasma genomes reported in the literature to examine several aspects of mycoplasma evolution. Strain-specific regions, including integrative and conjugal elements, and genome rearrangements and alterations in adhesin sequences were observed in the M. hyopneumoniae strains, and all of these were potentially related to pathogenicity. Genomic comparisons revealed that reduction in genome size implied loss of redundant metabolic pathways, with maintenance of alternative routes in different species. Horizontal gene transfer was consistently observed between M. synoviae and Mycoplasma gallisepticum. Our analyses indicated a likely transfer event of hemagglutinin-coding DNA sequences from M. gallisepticum to M. synoviae. PMID:16077101

  2. Immunological characterization of Mycoplasma hyopneumoniae recombinant proteins.

    PubMed

    Simionatto, Simone; Marchioro, Silvana B; Galli, Vanessa; Brum, Clarice B; Klein, Catia S; Rebelatto, Raquel; Silva, Everton F; Borsuk, Sibele; Conceição, Fabricio R; Dellagostin, Odir A

    2012-03-01

    Mycoplasma hyopneumoniae, the primary pathogen of enzootic pneumonia, is highly prevalent worldwide and causes major economic losses to the pig industry. Commercial vaccines are widely used in the control of this disease, however, they provide only partial protection. The aim of this study was to evaluate 34 recombinant proteins of M. hyopneumoniae expressed in Escherichia coli. Antigenic and immunogenic properties of these proteins were analyzed. For this, the proteins were tested against hyperimmune and convalescent pig sera through ELISA and Western blot. Immunogenicity of the recombinant proteins was evaluated in BALB/c mice following intramuscular inoculation. Most antigens were able to induce a strong immune response and sera from inoculated mice were able to recognize native proteins by cell ELISA and Western blot. Several recombinant proteins were specifically recognized by convalescent pig sera, indicating they are expressed during infection. These data may help to develop more efficacious vaccines against M. hyopneumoniae.

  3. Mycoplasma hyopneumoniae: from disease to vaccine development.

    PubMed

    Simionatto, Simone; Marchioro, Silvana Beutinger; Maes, Dominiek; Dellagostin, Odir Antônio

    2013-08-30

    Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia (EP), a disease that affects swine production worldwide. Vaccination is the most cost-effective strategy for the control and prevention of the disease. Despite efforts to control M. hyopneumoniae infection, significant economic losses in pig production continue to occur. The results of genome-based research have the potential to help understand the biology and pathogenesis of M. hyopneumoniae, and contribute to the development of more effective vaccines and diagnostic tests. In this review, the characteristics of M. hyopneumoniae related to pathogenesis and control measures will be discussed. Special emphasis will be placed on vaccination strategies that have been proposed with the use of reverse vaccinology approaches.

  4. Repetitive DNA sequences in Mycoplasma pneumoniae.

    PubMed Central

    Wenzel, R; Herrmann, R

    1988-01-01

    Two types of different repetitive DNA sequences called RepMP1 and RepMP2 were identified in the genome of Mycoplasma pneumoniae. The number of these repeated elements, their nucleotide sequence and their localization on a physical map of the M. pneumoniae genome were determined. The results show that RepMP1 appears at least 10 times and RepMP2 at least 8 times in the genome. The repeated elements are dispersed on the chromosome and, in three cases, linked to each other by a homologous DNA sequence of 400 bp. The elements themselves are 300 bp (for RepMP1) and 150 bp (for RepMP2) long showing a high degree of homology. One copy of RepMP2 is a translated part of the gene for the major cytadhesin protein P1 which is responsible for the adsorption of M. pneumoniae to its host cell. Images PMID:3138660

  5. Mycoplasma and Chlamydia pneumonia in pediatrics.

    PubMed

    Nelson, Christopher T

    2002-03-01

    Mycoplasma pneumoniae and Chlamydia pneumoniae are common respiratory pathogens in children 5 years of age and older. Although distinctly different in structure, these organisms share similar epidemiologic and clinical characteristics in human infection and disease. Pneumonia caused by these organisms usually occurs after infection of the upper respiratory tract, but may occur in the absence of antecedent upper respiratory infection. Diagnosis of infection with C. pneumoniae and M. pneumoniae is most often based on clinical findings alone, though definitive diagnosis of infection with either organism may be confirmed through serologic methods, culture, and nucleic acid-detection methods such as polymerase chain reaction. Macrolide antibiotics are highly effective in the treatment of infected children, leading to rapid clinical resolution and excellent long-term out-come in the majority of patients.

  6. Cytoskeletal elements in the bacterium Mycoplasma pneumoniae

    NASA Astrophysics Data System (ADS)

    Hegermann, Jan; Herrmann, Richard; Mayer, Frank

    2002-09-01

    Mycoplasma pneumoniae is a pathogenic eubacterium lacking a cell wall. Three decades ago, a "rod", an intracellular cytoskeletal structure, was discovered that was assumed to define and stabilize the elongated cell shape. Later, by treatment with detergent, a "Triton shell" (i.e. a fraction of detergent-insoluble cell material) could be obtained, believed to contain additional cytoskeletal elements. Now, by application of a modified Triton X-100 treatment, we are able to demonstrate that M. pneumoniae possesses a cytoskeleton consisting of a blade-like rod and a peripheral lining located close to the inner face of the cytoplasmic membrane, exhibiting features of a highly regular network. Attached "stalks" may support the cytoplasmic membrane. The rod was connected to the cell periphery by "spokes" and showed a defined ultrastructure. Its proximal end was found to be attached to a wheel-like complex. Fibrils extended from the proximal end of the rod into the cytoplasm.

  7. Comparison of strains of Mycoplasma iowae.

    PubMed

    Rhoades, K R

    1984-01-01

    Comparison of biochemical test results and protein electrophoretic patterns of 21 strains of Mycoplasma iowae indicated that all were similar. Comparison of agglutination test results indicated marked within-species antigenic variation. None of 21 antigens prepared from different strains were effective in demonstrating turkey antibody against five reference strains. Examination of sera from turkeys exposed by intra-air-sac inoculation to two pathogenic strains also indicated antigenic variation. Neither the M. iowae type-strain, Iowa 695, nor the other reference strains were effective in demonstrating antibody against both strains used to expose the turkeys. These findings suggest that antigenic variation may be a major problem in effective serodiagnosis of M. iowae infections.

  8. Biosynthesis of cholesteryl glucoside by Mycoplasma gallinarum.

    PubMed

    Smith, P F

    1971-12-01

    The biosynthesis of cholesteryl glucoside by Mycoplasma gallinarum strain J proceeds by the transfer of glucose from uridine-5'-diphosphoglucose to membrane-bound sterol. Galactose also can be coupled to cholesterol via uridine-5'-diphosphogalactose. The reaction is specific for the uridine-5'-diphospho sugars. Enzymatic activity is associated with the membrane. Treatment of the membrane to remove endogenous sterol inactivates the enzyme. Only sterol which has been bound to the membrane participates in the reaction. The optimum pH is about 8.0, and Mg(2+) is required. The reaction is unaffected by nucleotide triphosphate, uridine-5'-monophosphate, and uridine-5'-diphosphate. Reduction of pH to the optimum for beta-glucosidase in the membrane results in loss of synthesized glucoside. The enzyme is saturated at 0.5 mm uridine-5'-diphosphoglucose. The apparent K(m) of 2.05 x 10(-7) indicates a high affinity of the enzyme for the nucleotide sugar.

  9. Evaluation of Mycoplasma Inactivation during Production of Biologics: Egg-Based Viral Vaccines as a Model▿

    PubMed Central

    David, Selwyn A. Wilson; Volokhov, Dmitriy V.; Ye, Zhiping; Chizhikov, Vladimir

    2010-01-01

    Although mycoplasmas are generally considered to be harmless commensals, some mycoplasma species are able to cause infections in pediatric, geriatric, or immunocompromised patients. Thus, accidental contamination of biologics with mycoplasmas represents a potential risk for the health of individuals who receive cell-derived biological and pharmaceutical products. To assess the efficiency of inactivation of mycoplasmas by the agents used in the manufacture of egg-derived influenza vaccines, we carried out a series of experiments aimed at monitoring the viability of mycoplasmas spiked into both chicken allantoic fluid and protein-rich microbiological media and then treated with beta-propiolactone, formalin, cetyltrimethylammonium bromide, Triton X-100, and sodium deoxycholate, which are agents that are commonly used for virus inactivation and disruption of viral particles during influenza vaccine production. Twenty-two mycoplasma species (with one to four strains of each species) were exposed to these inactivating agents at different concentrations. The most efficient inactivation of the mycoplasmas evaluated was observed with either 0.5% Triton X-100 or 0.5% sodium deoxycholate. Cetyltrimethylammonium bromide at concentrations of ≥0.08% was also able to rapidly inactivate (in less than 30 min) all mycoplasmas tested. In contrast, negligible reductions in mycoplasma titers were observed with 0.0125 to 0.025% formaldehyde. However, increasing the concentration of formaldehyde to 0.1 to 0.2% improved the mycoplasmacidal effect. Incubation of mycoplasmas with 0.1% beta-propiolactone for 1 to 24 h had a marked mycoplasmacidal effect. A comparison of the mycoplasma inactivation profiles showed that strains of selected species (Mycoplasma synoviae, Mycoplasma gallisepticum, Mycoplasma orale, Mycoplasma pneumoniae, and Acholeplasma laidlawii) represent a set of strains that can be utilized to validate the effectiveness of mycoplasma clearance obtained by inactivation and

  10. [100 years of Mycoplasma--pathogenicity for domestic and farm animals].

    PubMed

    Kirchhoff, H; Runge, M

    1998-10-01

    The paper presents a short description of the history of mycoplasmology, the systematic and characteristics of mycoplasmas and the diseases caused by mycoplasmas in cattle, sheep and goats, swine, poultry, and rats and mice. The pathogenicity of mycoplasmas for cats, dogs and horses is discussed.

  11. Hemotropic mycoplasma in a free-ranging black howler monkey (Alouatta caraya) in Brazil.

    PubMed

    Santos, Leonilda C; Cubilla, Michelle P; de Moraes, Wanderlei; Cubas, Zalmir S; Oliveira, Marcos J; Estrada, Marko; Leutenegger, Christian M; Sykes, Jane E; Lindsay, Leann L; Marcondes, Mary; Barros Filho, Ivan R; Biondo, Alexander W

    2013-07-01

    Hemotropic mycoplasmas are bacteria that infect erythrocytes and cause subclinical infections to life-threatening disease. We describe hemotropic mycoplasma infection in a free-ranging black howler monkey (Alouatta caraya). This is the first molecular detection of a hemotropic mycoplasma in a nonhuman primate from Brazil.

  12. STS-41 Discovery, OV-103, glides over concrete runway 22 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 Discovery, Orbiter Vehicle (OV) 103, with nose landing gear (NLG) and main landing gear (MLG) deployed, glides over concrete runway 22 at Edwards Air Force Base (EAFB), California, prior to touchdown.

  13. STS-41 Discovery, OV-103, glides over concrete runway 22 at EAFB, California

    NASA Image and Video Library

    1990-10-10

    STS-41 Discovery, Orbiter Vehicle (OV) 103, with nose landing gear (NLG) and main landing gear (MLG) deployed, glides over concrete runway 22 at Edwards Air Force Base (EAFB), California, prior to touchdown.

  14. STS-41 Discovery, OV-103, glides over concrete runway 22 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 Discovery, Orbiter Vehicle (OV) 103, with nose landing gear (NLG) and main landing gear (MLG) deployed, glides over concrete runway 22 at Edwards Air Force Base (EAFB), California, prior to touchdown.

  15. Motor-Substrate Interactions in Mycoplasma Motility Explains Non-Arrhenius Temperature Dependence

    PubMed Central

    Chen, Jing; Neu, John; Miyata, Makoto; Oster, George

    2009-01-01

    Abstract Mycoplasmas exhibit a novel, substrate-dependent gliding motility that is driven by ∼400 “leg” proteins. The legs interact with the substrate and transmit the forces generated by an assembly of ATPase motors. The velocity of the cell increases linearly by nearly 10-fold over a narrow temperature range of 10–40°C. This corresponds to an Arrhenius factor that decreases from ∼45 kBT at 10°C to ∼10 kBT at 40°C. On the other hand, load-velocity curves at different temperatures extrapolate to nearly the same stall force, suggesting a temperature-insensitive force-generation mechanism near stall. In this article, we propose a leg-substrate interaction mechanism that explains the intriguing temperature sensitivity of this motility. The large Arrhenius factor at low temperature comes about from the addition of many smaller energy barriers arising from many substrate-binding sites at the distal end of the leg protein. The Arrhenius dependence attenuates at high temperature due to two factors: 1), the reduced effective multiplicity of energy barriers intrinsic to the multiple-site binding mechanism; and 2), the temperature-sensitive weakly facilitated leg release that curtails the power stroke. The model suggests an explanation for the similar steep, sub-Arrhenius temperature-velocity curves observed in many molecular motors, such as kinesin and myosin, wherein the temperature behavior is dominated not by the catalytic biochemistry, but by the motor-substrate interaction. PMID:19948122

  16. Specific Evolution of F1-Like ATPases in Mycoplasmas

    PubMed Central

    Dautant, Alain; Bouyssou, Guillaume; Labroussaa, Fabien; Sköllermo, Anna; Persson, Anja; Blanchard, Alain; Sirand-Pugnet, Pascal

    2012-01-01

    F1F0 ATPases have been identified in most bacteria, including mycoplasmas which have very small genomes associated with a host-dependent lifestyle. In addition to the typical operon of eight genes encoding genuine F1F0 ATPase (Type 1), we identified related clusters of seven genes in many mycoplasma species. Four of the encoded proteins have predicted structures similar to the α, β, γ and ε subunits of F1 ATPases and could form an F1-like ATPase. The other three proteins display no similarity to any other known proteins. Two of these proteins are probably located in the membrane, as they have three and twelve predicted transmembrane helices. Phylogenomic studies identified two types of F1-like ATPase clusters, Type 2 and Type 3, characterized by a rapid evolution of sequences with the conservation of structural features. Clusters encoding Type 2 and Type 3 ATPases were assumed to originate from the Hominis group of mycoplasmas. We suggest that Type 3 ATPase clusters may spread to other phylogenetic groups by horizontal gene transfer between mycoplasmas in the same host, based on phylogeny and genomic context. Functional analyses in the ruminant pathogen Mycoplasma mycoides subsp. mycoides showed that the Type 3 cluster genes were organized into an operon. Proteomic analyses demonstrated that the seven encoded proteins were produced during growth in axenic media. Mutagenesis and complementation studies demonstrated an association of the Type 3 cluster with a major ATPase activity of membrane fractions. Thus, despite their tendency toward genome reduction, mycoplasmas have evolved and exchanged specific F1-like ATPases with no known equivalent in other bacteria. We propose a model, in which the F1-like structure is associated with a hypothetical X0 sector located in the membrane of mycoplasma cells. PMID:22685606

  17. Efficiency of lift production in flapping and gliding flight of swifts.

    PubMed

    Henningsson, Per; Hedenström, Anders; Bomphrey, Richard J

    2014-01-01

    Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing with an elliptical planform. In flapping flight, on the other hand, the wing tip travels faster than the root, creating a spanwise velocity gradient. To compensate, the optimal wing shape should taper towards the tip (reducing the local chord) and/or twist from root to tip (reducing local angle of attack). We hypothesised that, if a bird is limited in its ability to morph its wings and adapt its wing shape to suit both flight modes, then a preference towards flapping flight optimization will be expected since this is the most energetically demanding flight mode. We tested this by studying a well-known flap-gliding species, the common swift, by measuring the wakes generated by two birds, one in gliding and one in flapping flight in a wind tunnel. We calculated span efficiency, the efficiency of lift production, and found that the flapping swift had consistently higher span efficiency than the gliding swift. This supports our hypothesis and suggests that even though swifts have been shown previously to increase their lift-to-drag ratio substantially when gliding, the wing morphology is tuned to be more aerodynamically efficient in generating lift during flapping. Since body drag can be assumed to be similar for both flapping and gliding, it follows that the higher total drag in flapping flight compared with gliding flight is primarily a consequence of an increase in wing profile drag due to the flapping motion, exceeding the reduction in induced drag.

  18. Model tests of gliding with different hindwing configurations in the four-winged dromaeosaurid Microraptor gui

    PubMed Central

    Alexander, David E.; Gong, Enpu; Martin, Larry D.; Burnham, David A.; Falk, Amanda R.

    2010-01-01

    Fossils of the remarkable dromaeosaurid Microraptor gui and relatives clearly show well-developed flight feathers on the hind limbs as well as the front limbs. No modern vertebrate has hind limbs functioning as independent, fully developed wings; so, lacking a living example, little agreement exists on the functional morphology or likely flight configuration of the hindwing. Using a detailed reconstruction based on the actual skeleton of one individual, cast in the round, we developed light-weight, three-dimensional physical models and performed glide tests with anatomically reasonable hindwing configurations. Models were tested with hindwings abducted and extended laterally, as well as with a previously described biplane configuration. Although the hip joint requires the hindwing to have at least 20° of negative dihedral (anhedral), all configurations were quite stable gliders. Glide angles ranged from 3° to 21° with a mean estimated equilibrium angle of 13.7°, giving a lift to drag ratio of 4.1:1 and a lift coefficient of 0.64. The abducted hindwing model’s equilibrium glide speed corresponds to a glide speed in the living animal of 10.6 m·s−1. Although the biplane model glided almost as well as the other models, it was structurally deficient and required an unlikely weight distribution (very heavy head) for stable gliding. Our model with laterally abducted hindwings represents a biologically and aerodynamically reasonable configuration for this four-winged gliding animal. M. gui’s feathered hindwings, although effective for gliding, would have seriously hampered terrestrial locomotion. PMID:20133792

  19. Glide: a new approach for rapid, accurate docking and scoring. 2. Enrichment factors in database screening.

    PubMed

    Halgren, Thomas A; Murphy, Robert B; Friesner, Richard A; Beard, Hege S; Frye, Leah L; Pollard, W Thomas; Banks, Jay L

    2004-03-25

    Glide's ability to identify active compounds in a database screen is characterized by applying Glide to a diverse set of nine protein receptors. In many cases, two, or even three, protein sites are employed to probe the sensitivity of the results to the site geometry. To make the database screens as realistic as possible, the screens use sets of "druglike" decoy ligands that have been selected to be representative of what we believe is likely to be found in the compound collection of a pharmaceutical or biotechnology company. Results are presented for releases 1.8, 2.0, and 2.5 of Glide. The comparisons show that average measures for both "early" and "global" enrichment for Glide 2.5 are 3 times higher than for Glide 1.8 and more than 2 times higher than for Glide 2.0 because of better results for the least well-handled screens. This improvement in enrichment stems largely from the better balance of the more widely parametrized GlideScore 2.5 function and the inclusion of terms that penalize ligand-protein interactions that violate established principles of physical chemistry, particularly as it concerns the exposure to solvent of charged protein and ligand groups. Comparisons to results for the thymidine kinase and estrogen receptors published by Rognan and co-workers (J. Med. Chem. 2000, 43, 4759-4767) show that Glide 2.5 performs better than GOLD 1.1, FlexX 1.8, or DOCK 4.01.

  20. Designer surface plasmon dispersion on a one-dimensional periodic slot metasurface with glide symmetry.

    PubMed

    Camacho, Miguel; Mitchell-Thomas, Rhiannon C; Hibbins, Alastair P; Roy Sambles, J; Quevedo-Teruel, Oscar

    2017-09-01

    In this Letter, we explore the dispersion of spoof surface plasmons supported by a single-layer glide-symmetric structure. This structure consists of an infinitely long double-notched slot perforated in a metal layer. The presence of a degeneracy of the two lowest-order modes at the Brillouin zone boundary, which have non-zero group velocity is explained and experimentally demonstrated. Further, the dependence of the band structure when glide-symmetric configuration is broken is also explored.

  1. Efficiency of Lift Production in Flapping and Gliding Flight of Swifts

    PubMed Central

    Henningsson, Per; Hedenström, Anders; Bomphrey, Richard J.

    2014-01-01

    Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing with an elliptical planform. In flapping flight, on the other hand, the wing tip travels faster than the root, creating a spanwise velocity gradient. To compensate, the optimal wing shape should taper towards the tip (reducing the local chord) and/or twist from root to tip (reducing local angle of attack). We hypothesised that, if a bird is limited in its ability to morph its wings and adapt its wing shape to suit both flight modes, then a preference towards flapping flight optimization will be expected since this is the most energetically demanding flight mode. We tested this by studying a well-known flap-gliding species, the common swift, by measuring the wakes generated by two birds, one in gliding and one in flapping flight in a wind tunnel. We calculated span efficiency, the efficiency of lift production, and found that the flapping swift had consistently higher span efficiency than the gliding swift. This supports our hypothesis and suggests that even though swifts have been shown previously to increase their lift-to-drag ratio substantially when gliding, the wing morphology is tuned to be more aerodynamically efficient in generating lift during flapping. Since body drag can be assumed to be similar for both flapping and gliding, it follows that the higher total drag in flapping flight compared with gliding flight is primarily a consequence of an increase in wing profile drag due to the flapping motion, exceeding the reduction in induced drag. PMID:24587260

  2. Docking performance of the glide program as evaluated on the Astex and DUD datasets: a complete set of glide SP results and selected results for a new scoring function integrating WaterMap and glide

    NASA Astrophysics Data System (ADS)

    Repasky, Matthew P.; Murphy, Robert B.; Banks, Jay L.; Greenwood, Jeremy R.; Tubert-Brohman, Ivan; Bhat, Sathesh; Friesner, Richard A.

    2012-06-01

    Glide SP mode enrichment results for two preparations of the DUD dataset and native ligand docking RMSDs for two preparations of the Astex dataset are presented. Following a best-practices preparation scheme, an average RMSD of 1.140 Å for native ligand docking with Glide SP is computed. Following the same best-practices preparation scheme for the DUD dataset an average area under the ROC curve (AUC) of 0.80 and average early enrichment via the ROC (0.1 %) metric of 0.12 were observed. 74 and 56 % of the 39 best-practices prepared targets showed AUC over 0.7 and 0.8, respectively. Average AUC was greater than 0.7 for all best-practices protein families demonstrating consistent enrichment performance across a broad range of proteins and ligand chemotypes. In both Astex and DUD datasets, docking performance is significantly improved employing a best-practices preparation scheme over using minimally-prepared structures from the PDB. Enrichment results for WScore, a new scoring function and sampling methodology integrating WaterMap and Glide, are presented for four DUD targets, hivrt, hsp90, cdk2, and fxa. WScore performance in early enrichment is consistently strong and all systems examined show AUC > 0.9 and superior early enrichment to DUD best-practices Glide SP results.

  3. Take-off and landing kinetics of a free-ranging gliding mammal, the Malayan colugo (Galeopterus variegatus)

    PubMed Central

    Byrnes, Greg; Lim, Norman T.-L; Spence, Andrew J

    2008-01-01

    Arboreal animals negotiate a highly three-dimensional world that is discontinuous on many spatial scales. As the scale of substrate discontinuity increases, many arboreal animals rely on leaping or gliding locomotion between distant supports. In order to successfully move through their habitat, gliding animals must actively modulate both propulsive and aerodynamic forces. Here we examined the take-off and landing kinetics of a free-ranging gliding mammal, the Malayan colugo (Galeopterus variegatus) using a custom-designed three-dimensional accelerometry system. We found that colugos increase the propulsive impulse to affect longer glides. However, we also found that landing forces are negatively associated with glide distance. Landing forces decrease rapidly as glide distance increases from the shortest glides, then level off, suggesting that the ability to reorient the aerodynamic forces prior to landing is an important mechanism to reduce velocity and thus landing forces. This ability to substantially alter the aerodynamic forces acting on the patagial wing in order to reorient the body is a key to the transition between leaping and gliding and allows gliding mammals to travel long distances between trees with reduced risk of injury. Longer glides may increase the access to distributed resources and reduce the exposure to predators in the canopy or on the forest floor. PMID:18252673

  4. Simulation for F.C.C. deformation texture by modified pencil glide theory[Face Centered Cubic

    SciTech Connect

    Masui, H.

    1999-11-26

    Inspired by the pencil glide theory for b.c.c. metal, modified pencil glide theory for f.c.c. metal was proposed, dividing the 12 glide systems of f.c.c. metal into three groups individually composed of eight {l{underscore}brace}111{r{underscore}brace}{l{underscore}angle}110{r{underscore}angle} glide systems around the principal axes X[100], Y[010] and Z[001]. These assumptions yielded two mathematical solutions {Omega}(3) and {Omega}(1). In {Omega}(3), from the three groups with four complete conjugated glide systems composed of, respectively, two glide systems of common {l{underscore}angle}110{r{underscore}angle} direction, only one group with the maximum plastic work may operate if the requirements are satisfied, otherwise glide systems in {Omega}(1) where one of the four conjugated glide systems is zero are activated. The model considering the 12 glide systems of f.c.c. as a whole explained many experimentally stable orientations in axisymmetric and rolling deformation. The differences between the two pencil glide theories for b.c.c. and f.c.c. are also discussed with data.

  5. The cost of living large: comparative gliding performance in flying lizards (Agamidae: Draco).

    PubMed

    McGuire, Jimmy A; Dudley, Robert

    2005-07-01

    Despite exhibiting considerable interspecific variation in body mass, flying lizards of the genus Draco are isometric in their area-mass scaling relationships and exhibit no significant compensatory variation in wing aspect ratio. Thus, larger species are expected to be relatively poor gliders, in lieu of behavioral or physiological compensation, when compared with smaller congeners. Here we tested this hypothesis by conducting gliding performance trials for 11 Draco species spanning virtually the entire size range of the genus. We considered three primary performance variables: maximum velocity adjusted for wind conditions, height lost over a standard horizontal glide distance, and glide angle. Comparative analysis confirmed that larger species are relatively poor gliders and do not compensate substantially for their higher wing loadings via either behavioral or physiological mechanisms. Flying lizards were found to exhibit substantial context-dependent variation in glide performance, with smaller species often exhibiting extensive variation in height lost and glide angle between trials. Variation also was observed in empirically derived velocity profiles, with only a subset of individuals appearing to perform equilibrium glides. Such size-dependent variation in performance has important consequences for the ecology and evolution of flying lizards and other glissant taxa.

  6. Aerodynamic consequences of wing morphing during emulated take-off and gliding in birds.

    PubMed

    Klaassen van Oorschot, Brett; Mistick, Emily A; Tobalske, Bret W

    2016-10-01

    Birds morph their wings during a single wingbeat, across flight speeds and among flight modes. Such morphing may allow them to maximize aerodynamic performance, but this assumption remains largely untested. We tested the aerodynamic performance of swept and extended wing postures of 13 raptor species in three families (Accipitridae, Falconidae and Strigidae) using a propeller model to emulate mid-downstroke of flapping during take-off and a wind tunnel to emulate gliding. Based on previous research, we hypothesized that (1) during flapping, wing posture would not affect maximum ratios of vertical and horizontal force coefficients (CV:CH), and that (2) extended wings would have higher maximum CV:CH when gliding. Contrary to each hypothesis, during flapping, extended wings had, on average, 31% higher maximum CV:CH ratios and 23% higher CV than swept wings across all biologically relevant attack angles (α), and, during gliding, maximum CV:CH ratios were similar for the two postures. Swept wings had 11% higher CV than extended wings in gliding flight, suggesting flow conditions around these flexed raptor wings may be different from those in previous studies of swifts (Apodidae). Phylogenetic affiliation was a poor predictor of wing performance, due in part to high intrafamilial variation. Mass was only significantly correlated with extended wing performance during gliding. We conclude that wing shape has a greater effect on force per unit wing area during flapping at low advance ratio, such as take-off, than during gliding. © 2016. Published by The Company of Biologists Ltd.

  7. Strongly gliding harmonic tremor during the 2009 eruption of Redoubt Volcano

    USGS Publications Warehouse

    Hotovec, Alicia J.; Prejean, Stephanie G.; Vidale, John E.; Gomberg, Joan S.

    2013-01-01

    During the 2009 eruption of Redoubt Volcano, Alaska, gliding harmonic tremor occurred prominently before six nearly consecutive explosions during the second half of the eruptive sequence. The fundamental frequency repeatedly glided upward from < 1 Hz to as high as 30 Hz in less than 10 min, followed by a relative seismic quiescence of 10 to 60 s immediately prior to explosion. High frequency (5 to 20 Hz) gliding returned during the extrusive phase, and lasted for 20 min to 3 h at a time. Although harmonic tremor is not uncommon at volcanoes, tremor at such high frequencies is a rare observation. These frequencies approach or exceed the plausible upper limits of many models that have been suggested for volcanic tremor. We also analyzed the behavior of a swarm of repeating earthquakes that immediately preceded the first instance of pre-explosion gliding harmonic tremor. We find that these earthquakes share several traits with upward gliding harmonic tremor, and favor the explanation that the gliding harmonic tremor at Redoubt Volcano is created by the superposition of increasingly frequent and regular, repeating stick–slip earthquakes through the Dirac comb effect.

  8. Novel approach for designing a hypersonic gliding-cruising dual waverider vehicle

    NASA Astrophysics Data System (ADS)

    Liu, Jun; Ding, Feng; Huang, Wei; Jin, Liang

    2014-09-01

    For a hypersonic gliding-cruising vehicle, the gliding Mach number is larger than the cruising Mach number. It may be useful to design the inlet shroud to act as the compression surface of the waverider, to ensure that the vehicle rides on the shock wave, during both the gliding and cruising phases. A new design concept, namely a gliding-cruising dual waverider, is proposed in the current study. During the gliding phase, the hypersonic vehicle rides on the shock wave at the design gliding Mach number, as the inlet shroud is designed to act as waverider's compression surface. During the cruising phase, when the inlet shroud is cast away or jettisoned, the hypersonic vehicle rides on the shock wave at the design cruising Mach number, as the forebody is designed to act as waverider's compression surface. Thus, the design methodology of the dual-cone-derived waverider is described based on the theory of conical flow. Finally, the numerical methods are utilized to verify the new design method of the aerodynamic configuration. This methodology proposed is useful to design a hypersonic vehicle for two regimes of flight.

  9. Flight Modes in Migrating European Bee-Eaters: Heart Rate May Indicate Low Metabolic Rate during Soaring and Gliding

    PubMed Central

    Sapir, Nir; Wikelski, Martin; McCue, Marshall D.; Pinshow, Berry; Nathan, Ran

    2010-01-01

    Background Many avian species soar and glide over land. Evidence from large birds (mb>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR). Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to be lower than that of flapping flight. Nevertheless, several small bird species routinely soar and glide. Methodology/Principal Findings To estimate the energetic cost of soaring-gliding flight in small birds, we measured heart beat frequencies of free-ranging migrating European bee-eaters (Merops apiaster, mb∼55 g) using radio telemetry, and established the relationship between heart beat frequency and metabolic rate (by indirect calorimetry) in the laboratory. Heart beat frequency during sustained soaring-gliding was 2.2 to 2.5 times lower than during flapping flight, but similar to, and not significantly different from, that measured in resting birds. We estimated that soaring-gliding metabolic rate of European bee-eaters is about twice their basal metabolic rate (BMR), which is similar to the value estimated in the black-browed albatross Thalassarche (previously Diomedea) melanophrys, mb∼4 kg). We found that soaring-gliding migration speed is not significantly different from flapping migration speed. Conclusions/Significance We found no evidence that soaring-gliding speed is slower than flapping flight in bee-eaters, contradicting earlier estimates that implied a migration speed penalty for using soaring-gliding rather than flapping flight. Moreover, we suggest that small birds soar and glide during migration, breeding, dispersal, and other stages in their annual cycle because it may entail a low energy cost of transport. We propose that the energy cost of soaring-gliding may be proportional to BMR regardless of bird size, as theoretically deduced by earlier studies

  10. The RuvA homologues from Mycoplasma genitalium and Mycoplasma pneumoniae exhibit unique functional characteristics.

    PubMed

    Sluijter, Marcel; Estevão, Silvia; Hoogenboezem, Theo; Hartwig, Nico G; van Rossum, Annemarie M C; Vink, Cornelis

    2012-01-01

    The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ) resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvA(Mpn) and RuvA(Mge), respectively) were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvA(Mpn) and RuvA(Mge) (68.8% identity), substantial differences were found between these proteins in their activities. First, RuvA(Mge) was found to preferentially bind to HJs, whereas RuvA(Mpn) displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvA(Mpn) is able to form two distinct complexes with HJs, RuvA(Mge) only produced a single HJ complex. Third, RuvA(Mge) stimulated the DNA helicase and ATPase activities of RuvB(Mge), whereas RuvA(Mpn) did not augment RuvB activity. Finally, while both RuvA(Mge) and RecU(Mge) efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecU(Mge).

  11. The RuvA Homologues from Mycoplasma genitalium and Mycoplasma pneumoniae Exhibit Unique Functional Characteristics

    PubMed Central

    Sluijter, Marcel; Estevão, Silvia; Hoogenboezem, Theo; Hartwig, Nico G.; van Rossum, Annemarie M. C.; Vink, Cornelis

    2012-01-01

    The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ) resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvAMpn and RuvAMge, respectively) were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvAMpn and RuvAMge (68.8% identity), substantial differences were found between these proteins in their activities. First, RuvAMge was found to preferentially bind to HJs, whereas RuvAMpn displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvAMpn is able to form two distinct complexes with HJs, RuvAMge only produced a single HJ complex. Third, RuvAMge stimulated the DNA helicase and ATPase activities of RuvBMge, whereas RuvAMpn did not augment RuvB activity. Finally, while both RuvAMge and RecUMge efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecUMge. PMID:22666500

  12. Strain Patterns in Models of Spreading-Gliding Nappes

    NASA Astrophysics Data System (ADS)

    Brun, Jean-Pierre; Merle, Olivier

    1985-12-01

    Three experiments have been carried out in order to study the progressive and finite strain in nappes where gravitational spreading and gliding occur together. These experimental models were made from analogue materials able to collapse under their own weight on an inclined plane. Throughout most of the models the stretch trajectories in a vertical plane parallel to the flow show a low-amplitude sigmoidal pattern consistent with a previous theoretical model. Other stretch trajectories exist at the front and back ends of each model. The kinematic significance of all these trajectories is discussed in detail. Highest strain intensities are always found next to the base of the model. Strain paths calculated at different stages of flow indicate clearly that nowhere in the model is the motion simple. There is a complex combination in time and space of simple and pure shear, except at the base of the model where the motion approximates a simple shearing. Near the two parallel lateral sides of the model a lateral boundary effect can be observed from the strong curvature of the transverse markers (surface grid and vertical layers). Strain paths have also been estimated in this complex zone where wrench shearing is superimposed upon vertical shortening and thrust shearing. The geological implications of these experimental models are discussed in relation to recent theoretical studies and field work.

  13. Dislocation Onset and Glide in Carbon Nanotubes under Torsion

    NASA Astrophysics Data System (ADS)

    Dumitrica, Traian; Zhang, Dong-Bo; James, Richard

    2009-03-01

    The torsional plastic response of carbon nanotubes is comprehensively described in the objective molecular dynamics framework [1-3]. It is shown that an (n,m) tube is prone to slip along a nearly-axial helical path, which introduces a distinct (+1,-1) change in the wrapping index. The low energy realization occurs without loss of mass, via nucleation of a 5-7-7-5 dislocation dipole, followed by a nearly-axial glide of the 5-7 dislocation. The onset of plasticity depends not only on chirality but also on handedness. For a given handedness of the applied twist, chiral tubes of opposed handedness are most susceptible to yield. A right-handed applied twist on an armchair (zig-zag) tube leads to a right- (left-) handed tube. [4pt] [1] T. Dumitrica and R.D. James, Objective Molecular Dynamics, Journal of the Mechanics and Physics of Solids 55, 2206 (2007). [0pt] [2] D.-B. Zhang, M. Hua, and T. Dumitrica, Stability of Polycrystalline and Wurtzite Si Nanowires via Symmetry-Adapted Tight-Binding Objective Molecular Dynamics, Journal of Chemical Physics 128, 084104 (2008). [0pt] [3] D.-B. Zhang and T. Dumitrica, Elasticity of Ideal Single-Walled Carbon Nanotubes via Symmetry-Adapted Tight-Binding Objective Modeling, Applied Physics Letters 93, 031919 (2008).

  14. Transition of dislocation glide to shear transformation in shocked tantalum

    DOE PAGES

    Hsiung, Luke L.; Campbell, Geoffrey H.

    2017-02-28

    A TEM study of pure tantalum and tantalum-tungsten alloys explosively shocked at a peak pressure of 30 GPa (strain rate: ~1 x 104 sec-1) is presented. While no ω (hexagonal) phase was found in shock-recovered pure Ta and Ta-5W that contain mainly a low-energy cellular dislocation structure, shock-induced ω phase was found to form in Ta-10W that contains evenly distributed dislocations with a stored dislocation density higher than 1 x 1012 cm-2. The TEM results clearly reveal that shock-induced α (bcc) → ω (hexagonal) shear transformation occurs when dynamic recovery reactions which lead the formation low-energy cellular dislocation structure becomemore » largely suppressed in Ta-10W shocked under dynamic (i.e., high strain-rate and high-pressure) conditions. A novel dislocation-based mechanism is proposed to rationalize the transition of dislocation glide to twinning and/or shear transformation in shock-deformed tantalum. Lastly, twinning and/or shear transformation take place as an alternative deformation mechanism to accommodate high-strain-rate straining when the shear stress required for dislocation multiplication exceeds the threshold shear stresses for twinning and/or shear transformation.« less

  15. Loop formation of microtubules during gliding at high density

    NASA Astrophysics Data System (ADS)

    Liu, Lynn; Tüzel, Erkan; Ross, Jennifer L.

    2011-09-01

    The microtubule cytoskeleton, including the associated proteins, forms a complex network essential to multiple cellular processes. Microtubule-associated motor proteins, such as kinesin-1, travel on microtubules to transport membrane bound vesicles across the crowded cell. Other motors, such as cytoplasmic dynein and kinesin-5, are used to organize the cytoskeleton during mitosis. In order to understand the self-organization processes of motors on microtubules, we performed filament-gliding assays with kinesin-1 motors bound to the cover glass with a high density of microtubules on the surface. To observe microtubule organization, 3% of the microtubules were fluorescently labeled to serve as tracers. We find that microtubules in these assays are not confined to two dimensions and can cross one other. This causes microtubules to align locally with a relatively short correlation length. At high density, this local alignment is enough to create 'intersections' of perpendicularly oriented groups of microtubules. These intersections create vortices that cause microtubules to form loops. We characterize the radius of curvature and time duration of the loops. These different behaviors give insight into how crowded conditions, such as those in the cell, might affect motor behavior and cytoskeleton organization.

  16. Survival and replication of Mycoplasma species in recycled bedding sand and association with mastitis on dairy farms in Utah.

    PubMed

    Justice-Allen, A; Trujillo, J; Corbett, R; Harding, R; Goodell, G; Wilson, D

    2010-01-01

    Mycoplasma spp., usually Mycoplasma bovis, are important bovine pathogens that can cause mastitis, metritis, pneumonia, and arthritis. The currently documented routes of transmission of Mycoplasma spp. are through contaminated milking equipment and by direct animal contact. The existence of environmental sources for Mycoplasma spp. and their role in transmission and clinical disease is poorly characterized. Mycoplasma spp. (confirmed as M. bovis in 2 of 4 samples tested using PCR) was found in recycled bedding sand originating from a dairy experiencing an outbreak of clinical mycoplasma mastitis. Mycoplasma spp. were subsequently found in bedding sand from 2 other dairies whose bulk-tank milk was mycoplasma-positive. The association between the occurrence of Mycoplasma spp. in recycled bedding sand and mycoplasma mastitis in cows was further investigated using a pile of recycled sand from dairy 1. Study objectives included the determination of factors associated with the concentration of Mycoplasma spp. in recycled bedding sand and the duration of survival of mycoplasmas in the sand. We also evaluated the efficacy of 2 disinfectants at 2 different concentrations each for the elimination of Mycoplasma spp. from contaminated sand. Mycoplasma spp. survived in the sand pile for 8 mo. The concentration of Mycoplasma spp. within the sand pile was directly related to temperature and precipitation. It was also positively associated with the growth of gram-negative microorganisms, suggesting the possibility of the formation of a biofilm. Ideal temperatures for replication of Mycoplasma spp. occurred between 15 and 20 degrees C. Moisture in the sand and movement of the sand pile also appeared to play a role in replication of mycoplasmas. We found that 0.5% sodium hypochlorite or 2% chlorhexidine were efficacious in eliminating Mycoplasma spp. from contaminated bedding sand. Recycled bedding sand could be an environmental source of Mycoplasma spp., including M. bovis

  17. The in vitro effect of six antimicrobials against Mycoplasma putrefaciens, Mycoplasma mycoides subsp. mycoides LC and Mycoplasma capricolum subsp. capricolum isolated from sheep and goats in Jordan.

    PubMed

    Al-Momani, W; Nicholas, R A J; Janakat, S; Abu-Basha, E; Ayling, R D

    2006-01-01

    Respiratory disease in sheep and goats is a major problem in Jordan and is often associated with Mycoplasma species. Without effective vaccines, control is mainly by chemotherapy, but the uncontrolled use of antimicrobials has led to concerns about the potential development of antimicrobial resistance. The in vitro effect of chloramphenicol, florfenicol, enrofloxacin, tylosin, erythromycin and oxytetracycline was determined against 32 isolates of Mycoplasma species-M. mycoides subsp. mycoides LC (6), M. capricolum subsp. capricolum (8) and M. putrefaciens (18), all isolated from either nasal swabs or milk, from sheep and goats in different regions of Jordan. The antimicrobial susceptibility showed some Mycoplasma species-specific differences, with M. capricolum subsp. capricolum being more susceptible to tylosin and erythromycin. Chloramphenicol and florfenicol were the least effective for all three Mycoplasma species. No trends or significant differences in antimicrobial susceptibilities were observed between sheep and goat isolates, between milk or nasal swab isolates, or between isolates from different regions of Jordan. Some isolates of M. capricolum subsp. capricolum and M. putrefaciens showed higher MIC levels with oxytetracycline, as did two isolates of M. mycoides subsp. mycoides LC with tylosin, possibly indicating signs of development of antimicrobial resistance.

  18. Metabolomics reveals mycoplasma contamination interferes with the metabolism of PANC-1 cells.

    PubMed

    Yu, Tao; Wang, Yongtao; Zhang, Huizhen; Johnson, Caroline H; Jiang, Yiming; Li, Xiangjun; Wu, Zeming; Liu, Tian; Krausz, Kristopher W; Yu, Aiming; Gonzalez, Frank J; Huang, Min; Bi, Huichang

    2016-06-01

    Mycoplasma contamination is a common problem in cell culture and can alter cellular functions. Since cell metabolism is either directly or indirectly involved in every aspect of cell function, it is important to detect changes to the cellular metabolome after mycoplasma infection. In this study, liquid chromatography mass spectrometry (LC/MS)-based metabolomics was used to investigate the effect of mycoplasma contamination on the cellular metabolism of human pancreatic carcinoma cells (PANC-1). Multivariate analysis demonstrated that mycoplasma contamination induced significant metabolic changes in PANC-1 cells. Twenty-three metabolites were identified and found to be involved in arginine and purine metabolism and energy supply. This study demonstrates that mycoplasma contamination significantly alters cellular metabolite levels, confirming the compelling need for routine checking of cell cultures for mycoplasma contamination, particularly when used for metabolomics studies. Graphical abstract Metabolomics reveals mycoplasma contamination changes the metabolome of PANC-1 cells.

  19. Coupled gas flow-plasma model for a gliding arc: investigations of the back-breakdown phenomenon and its effect on the gliding arc characteristics

    NASA Astrophysics Data System (ADS)

    Sun, S. R.; Kolev, St.; Wang, H. X.; Bogaerts, A.

    2017-01-01

    We present a 3D and 2D Cartesian quasi-neutral plasma model for a low current argon gliding arc discharge, including strong interactions between the gas flow and arc plasma column. The 3D model is applied only for a short time of 0.2 ms due to its huge computational cost. It mainly serves to verify the reliability of the 2D model. As the results in 2D compare well with those in 3D, they can be used for a better understanding of the gliding arc basic characteristics. More specifically, we investigate the back-breakdown phenomenon induced by an artificially controlled plasma channel, and we discuss its effect on the gliding arc characteristics. The back-breakdown phenomenon, or backward-jump motion of the arc, as observed in the experiments, results in a drop of the gas temperature, as well as in a delay of the arc velocity with respect to the gas flow velocity, allowing more gas to pass through the arc, and thus increasing the efficiency of the gliding arc for gas treatment applications.

  20. The polarity of myxobacterial gliding is regulated by direct interactions between the gliding motors and the Ras homolog MglA

    PubMed Central

    Nan, Beiyan; Bandaria, Jigar N.; Guo, Kathy Y.; Fan, Xue; Moghtaderi, Amirpasha; Yildiz, Ahmet; Zusman, David R.

    2015-01-01

    Gliding motility in Myxococcus xanthus is powered by flagella stator homologs that move in helical trajectories using proton motive force. The Frz chemosensory pathway regulates the cell polarity axis through MglA, a Ras family GTPase; however, little is known about how MglA establishes the polarity of gliding, because the gliding motors move simultaneously in opposite directions. Here we examined the localization and dynamics of MglA and gliding motors in high spatial and time resolution. We determined that MglA localizes not only at the cell poles, but also along the cell bodies, forming a decreasing concentration gradient toward the lagging cell pole. MglA directly interacts with the motor protein AglR, and the spatial distribution of AglR reversals is positively correlated with the MglA gradient. Thus, the motors moving toward lagging cell poles are less likely to reverse, generating stronger forward propulsion. MglB, the GTPase-activating protein of MglA, regulates motor reversal by maintaining the MglA gradient. Our results suggest a mechanism whereby bacteria use Ras family proteins to modulate cellular polarity. PMID:25550521

  1. EPS-I Polysaccharide Protects Mycoplasma pulmonis from Phagocytosis

    PubMed Central

    Shaw, Brandon M.; Daubenspeck, James M.; Simmons, Warren L.; Dybvig, Kevin

    2012-01-01

    Few mycoplasmal polysaccharides have been described and little is known about their role in pathogenesis. The infection of mice with Mycoplasma pulmonis has been utilized in many in vivo and in vitro studies to gain a better understanding of host-pathogen interactions during chronic respiratory infection. Although alveolar macrophages have a primary role in host defense, M. pulmonis is killed inefficiently in vitro. One antiphagocytic factor produced by the mycoplasma is the family of phase- and size-variable Vsa lipoproteins. However, bacteria generally employ multiple strategies for combating host defenses, with capsular polysaccharide often having a key role. We show here that mutants lacking the EPS-I polysaccharide of M. pulmonis exhibit increased susceptibility to binding and subsequent killing by alveolar macrophages. These results give further insight into how mycoplasmas are able to avoid the host immune system and sustain a chronic infection. PMID:23190331

  2. The polymerase chain reaction for Mycoplasma gallisepticum detection.

    PubMed

    Kempf, I; Blanchard, A; Gesbert, F; Guittet, M; Bennejean, G

    1993-12-01

    On the basis of the aligned 16S rRNA sequences of Mollicutes, a pair of primers was chosen for the detection of Mycoplasma gallisepticum. When used in the polymerase chain reaction (PCR), the primers detected a specific amplification of all Mg strains tested, yielding an expected 330 bp product. Amplification was not detected when other Mollicutes or E. coli were used as PCR templates. SPF chickens were experimentally inoculated with two strains of M. gallisepticum or Mycoplasma iowae. Tracheal swabs were collected 8, 15, 20 and 28 days after inoculation, and cultured for mycoplasma or tested by PCR. PCR products were detected by hybridization with a digoxigenin-labeled probe and by chemiluminescence. The results showed that culture was positive for 49/73 swabs while PCR detected 70/72 positive samples. Thus, PCR can provide the basis of a sensitive, specific, rapid and non-radio-active method for detecting M. gallisepticum.

  3. Effects of Glide Path on the Centering Ability and Preparation Time of Two Reciprocating Instruments

    PubMed Central

    Coelho, Marcelo Santos; Fontana, Carlos Eduardo; Kato, Augusto Shoji; de Martin, Alexandre Sigrist; da Silveira Bueno, Carlos Eduardo

    2016-01-01

    Introduction: The aim of this in vitro study was to evaluate the effects of establishing glide path on the centering ability and preparation time of two single-file reciprocating systems in mesial root canals of mandibular molars. Methods and Materials: Sixty extracted mandibular molars with curvatures of 25-39 degrees and separate foramina for the mesiobuccal and mesiolingual canals, were divided into four groups (n=15); WaveOne+glide path; WaveOne; Reciproc+glide path and Reciproc. Non-patent canals were excluded and only one canal in each tooth was instrumented. A manual glide path was established in first and third groups with #10, 15 and 20 hand K-files. Preparation was performed with reciprocating in-and-out motion, with a 3-4 mm amplitude and slight apical pressure. Initial and final radiographs were taken to analyze the amount of dentin removed in the instrumented canals. The radiographs were superimposed with an image editing software and examined to assess discrepancies at 3-, 6- and 9-mm distances from the apex. The Kruskal-Wallis test was used for statistical analysis. The level of significance was set at 0.05. Results: Preparation in groups without glide paths was swifter than the other groups (P=0.001). However, no difference was observed regarding centering ability. Conclusion: Establishing a glide path increased the total instrumentation time for preparing curved canals with WaveOne and Reciproc instruments. Glide path had no influence on the centering ability of these systems. PMID:26843875

  4. Occurrence of Urease in T Strains of Mycoplasma

    PubMed Central

    Shepard, Maurice C.; Lunceford, Carl D.

    1967-01-01

    A previously unknown metabolite necessary for growth of T strains of Mycoplasma in artificial culture media has been identified as urea. The source of this metabolite was the mammalian plasma or serum enrichment of the culture medium. Normal horse serum was the most satisfactory native protein enrichment for cultivation of T strains of mycoplasma, and it is believed that its superior performance in agar and fluid culture media is associated with its relatively high urea content (approximately 40 mg/100 ml). T-strain urease activity was maximal at pH 6.0 ± 0.5. This is also the optimal pH for growth of T strains. Substrate concentrations greater than 1.0% urea were inhibitory to growth and urease activity of T-strain organisms, and optimal urea concentrations in fluid media appeared to lie within the range of 0.008 to 0.01 m. This range of urea concentration permitted maximal growth of T-strain organisms without rapid loss of viability due to excessive ammonia accumulation and rise in pH to lethal levels. T strains of Mycoplasma were cultivated in a serum-free fluid medium containing urea as the only added metabolite and nitrogen source. T strains are the only known human mycoplasmas which exhibit urease activity, and this biochemical marker can be employed as an aid in the detection and identification of T strains of Mycoplasma (urease color test) and in distinguishing T strains from other members of the human Mycoplasma group. PMID:6025439

  5. Mechanisms of volume regulation in Mycoplasma gallisepticum

    SciTech Connect

    Linker, C.S.

    1987-01-01

    Mycoplasma gallisepticum, a cell wall-less bacterium, must confront the problem of colloid osmotic swelling. Cell volume was determined by optical density and intracellular water measurements. Transmembrane pH and electrical gradients were determined by the distribution of the weak acid benzoate and lipophilic cation tetraphenylphosphonium respectively. Cells incubated in sodium chloride without glucose exhibited a progressive fall in ATP over several hours. When ATP fell below 40 uM the cells swelled, leaked protein and became permeable to inulin. Subsequent addition of glucose induced shrinkage and restored the original permeability properties. Energized cells exhibited an electrochemical gradient of protons of up to 130 mV, inside negative and alkaline. The proton-ATPase inhibitor dicyclohexylcarbodiimide (DCCD), which collapsed the chemical and electrical components of the proton gradient, induced rapid swelling despite high ATP levels thus implicating the proton gradient in volume regulation. Either the pH gradient or the membrane potential could maintain volume. Energy-dependent sodium efflux in exchange for protons was demonstrated in sodium-loaded cells using radioactive sodium and 9-aminoacridine fluorescence to follow sodium and proton translocation respectively.

  6. Mycoplasma genitalium: An Emerging Sexually Transmitted Infection.

    PubMed

    Munoz, Jessian L; Goje, Oluwatosin Jaiyeoba

    2016-01-01

    Mycoplasma genitalium has been recognized as a cause of male urethritis, and there is now evidence suggesting that it causes cervicitis and pelvic inflammatory disease in women. M. genitalium is a slow growing organism, and, with the advent of nucleic acid amplification test (NAAT), more studies are being performed, and knowledge about the pathogenicity of this organism elucidated. With NAAT detection, treatment modalities have been studied, and the next challenge is to determine the most effective antimicrobial therapy. Doxycycline, the first-line antibiotic for urethritis, is largely ineffective in the treatment of M. genitalium and furthermore, resistance to macrolide has also emerged. The most effective drug is Moxifloxacin although there are emerging reports of resistance to it in various parts of the world. This paper not only highlights the current research and knowledge, but also reviews the diversity of health implications on the health of men and women infected with M. genitalium. Alternate antibiotics and the impact of M. genitalium on infertility are areas that require more studies as we continue to research into this microorganism.

  7. Mycoplasma genitalium, an emerging sexually transmitted pathogen.

    PubMed

    Cazanave, C; Manhart, L E; Bébéar, C

    2012-09-01

    Mycoplasma genitalium is a sexually transmitted organism associated with non-gonococcal urethritis in men and several inflammatory reproductive tract syndromes in women such as cervicitis, pelvic inflammatory disease, and infertility. There was evidence for an association of M. genitalium with endometritis and pelvic inflammatory disease (PID), but additional studies are necessary to confirm this. The evidence as to whether M. genitalium can cause adverse pregnancy outcomes such as preterm labor is conflicting. But the authors of some studies on M. genitalium as a cause of infertility have reported this association. This species is very difficult to culture; thus, nucleic acid amplification testing is the only method available for M. genitalium detection. The lack of a cell wall makes M. genitalium intrinsically resistant to antibiotics acting at this level, such as beta-lactams. The treatment of M. genitalium infections is not standardized. Macrolides are recommended, especially single-dose azithromycin; tetracyclines are responsible for a great number of therapeutic failures even no resistance mechanism has yet been demonstrated. Acquired resistance to macrolides and fluoroquinolones leading to therapeutic failure has also been reported. All this raises the issue of the most appropriate therapeutic management and requires drafting diagnostic and therapeutic guidelines for the treatment of M. genitalium infections.

  8. Neonate with Mycoplasma hominis meningoencephalitis given moxifloxacin.

    PubMed

    Wildenbeest, Joanne G; Said, Ines; Jaeger, Bregje; van Hest, Reinier M; van de Beek, Diederik; Pajkrt, Dasja

    2016-11-01

    Mycoplasma hominis is a commensal organism in the genitourinary tract that can cause life-threatening CNS infections in neonates after intrauterine infection or through vertical transmission during birth. We present a case of an 11-day-old neonate presenting with fever and supporting laboratory evidence of a CNS infection. No systemic maternal infection or maternal genitourinary tract infection occurred at the time of delivery. Empirical treatment was initiated, consisting of amoxicillin, cefotaxime, and aciclovir. After clinical deterioration, 16S ribosomal DNA PCR in cerebrospinal fluid detected M hominis, antibiotic treatment was switched to moxifloxacin, and pharmacokinetic data were obtained. This Grand Round illustrates the challenges that exist in the diagnosis and treatment of M hominis meningoencephalitis: bacterial cultures are often negative and recommended empirical antimicrobials do not provide adequate antimicrobial coverage. Optimal antimicrobial treatment regimens for M hominis meningoencephalitis are unknown. Although we describe successful treatment of a neonate with a complicated M hominis meningoencephalitis with moxifloxacin, caution with fluoroquinolone monotherapy (including moxifloxacin) has to be taken into account because resistance to fluoroquinolones has previously been described. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Tissue sequestration of 'Candidatus Mycoplasma turicensis'.

    PubMed

    Novacco, Marilisa; Riond, Barbara; Meli, Marina L; Grest, Paula; Hofmann-Lehmann, Regina

    2013-12-27

    'Candidatus Mycoplasma turicensis' ('Candidatus M. turicensis') is a hemoplasma species that infects felids. It differs from other feline hemoplasma species due to its particular infection kinetics and phylogenetic similarity to rodent hemoplasma species. The lower and shorter bacteremia produced by 'Candidatus M. turicensis' suggests a possible tissue sequestration of the organism. The aim of this study was to explore this possibility. Five specified-pathogen free cats were subcutaneously inoculated with 'Candidatus M. turicensis' and sacrificed 86 days after inoculation. Thirty-one selected organs were collected upon necropsy, and samples were analyzed by real-time Taqman(®) PCR. The humoral immune response was monitored by DnaK ELISA. All five cats had detectable 'Candidatus M. turicensis' loads in the majority (52-100%) of the tested tissues. High 'Candidatus M. turicensis' tissue loads (average 3.46×10(4) copies/10 mg) were detected in the samples. The presence of the organisms in the tissues could not be explained by the blood burdens because the blood of four out of five cats tested PCR-negative at the time of necropsy. This is the first study to describe the distribution of 'Candidatus M. turicensis' in various organs; it also demonstrates that, in contrast to other feline hemoplasma species, significant sequestration of 'Candidatus M. turicensis' occurs in many tissues. These results represent an important step toward the understanding of the pathogenesis of 'Candidatus M. turicensis'.

  10. Selective medium for culture of Mycoplasma hyopneumoniae.

    PubMed

    Cook, Beth S; Beddow, Jessica G; Manso-Silván, Lucía; Maglennon, Gareth A; Rycroft, Andrew N

    2016-11-15

    The fastidious porcine respiratory pathogen Mycoplasma hyopneumoniae has proven difficult to culture since it was first isolated in 1965. A reliable solid medium has been particularly challenging. Moreover, clinical and pathological samples often contain the fast-growing M. hyorhinis which contaminates and overgrows M. hyopneumoniae in primary culture. The aim of this study was to optimise the culture medium for recovery of M. hyopneumoniae and to devise a medium for selection of M. hyopneumoniae from clinical samples also containing M. hyorhinis. The solid medium devised by Niels Friis was improved by use of Purified agar and incorporation of DEAE-dextran. Addition of glucose or neutralization of acidity in liquid medium with NaOH did not improve the final yield of viable organisms or alter the timing of peak viability. Analysis of the relative susceptibility of M. hyopneumoniae and M. hyorhinis strains to four antimicrobials showed that M. hyopneumoniae is less susceptible than M. hyorhinis to kanamycin. This was consistent in all UK and Danish strains tested. A concentration of 2μg/ml of kanamycin selectively inhibited the growth of all M. hyorhinis tested, while M. hyopneumoniae was able to grow. This forms the basis of an effective selective culture medium for M. hyopneumoniae.

  11. Mycoplasma alkalescens demonstrated in bronchoalveolar lavage of cattle in Denmark

    PubMed Central

    Kokotovic, Branko; Friis, Niels F; Ahrens, Peter

    2007-01-01

    Mycoplasma alkalescens is an arginine-metabolizing mycoplasma, which has been found in association with mastitis and arthritis in cattle. Routine bacteriological examination of 17 bronchoalveolar lavage samples from calves with pneumonia in a single herd in Denmark, identified M. alkalescens in eight samples. The organism was found as a sole bacterilogical findings in five of the samples as well as in combination with Mannheimia haemolytica, Haemophilus somni and Salmonella Dublin. This is the first report of isolation of M. alkalescens in Denmark. PMID:17204146

  12. Successive synovial Mycoplasma hominis isolates exhibit apparent antigenic variation.

    PubMed Central

    Olson, L D; Renshaw, C A; Shane, S W; Barile, M F

    1991-01-01

    The expression of surface proteins by 14 successive Mycoplasma hominis isolates obtained from the synovial fluid of a chronically infected septic arthritis patient was examined. Marked differences in the expression of surface proteins, as determined by monoclonal antibodies raised against the first isolate, were observed. However, identical restriction patterns and virtually identical hybridization patterns with probes containing the conserved genes of the Mycoplasma capricolum rRNA operon and the Escherichia coli elongation factor Tu suggest that the protein differences might reflect antigenic variation by M. hominis during infection. Images PMID:1879948

  13. Proposal for 'Candidatus Mycoplasma haemomuris subsp. musculi' in mice, and 'Candidatus Mycoplasma haemomuris subsp. ratti' in rats.

    PubMed

    Harasawa, Ryô; Fujita, Hiromi; Kadosaka, Teruki; Ando, Shuji; Rikihisa, Yasuko

    2015-02-01

    Mycoplasma haemomuris is causative of infectious anaemia or splenomegaly in rodents. We examined the nucleotide sequences of the non-ribosomal genes, rnpB and dnaK, in strains of the species M. haemomuris detected in small field mice and black rats. rnpB nucleotide sequences in strains of the species M. haemomuris isolated from small field mice and black rats had only 89 % sequence similarity, suggesting their separation into two distinct subgroups. dnaK had a nucleotide sequence similarity of 84 % between the subgroups. These results support the classification of M. haemomuris into two genetically distinct subgroups. Here we propose the establishment of these subgroups as 'Candidatus Mycoplasma haemomuris subsp. musculi', detected in small field mice (Apodemus argenteus), and 'Candidatus Mycoplasma haemomuris subsp. ratti', detected in black rats (Rattus rattus).

  14. Experimental studies on the pathogenicity of Mycoplasma ovipneumoniae and Mycoplasma arginini for the respiratory tract of goats.

    PubMed Central

    Goltz, J P; Rosendal, S; McCraw, B M; Ruhnke, H L

    1986-01-01

    Mycoplasma ovipneumoniae and Mycoplasma arginini were the species of Mollicutes most commonly isolated from 175 goats with respiratory disease in Ontario. The pathogenicity of M. ovipneumoniae, strain B321B and M. arginini, strain D53e, was assessed in goats following endobronchial inoculation. One out of three two year old goats developed fever after inoculation with a pure culture of strain B321B, and it had extensive subacute fibrinous pleuritis when necropsied three weeks later. Neither of the remaining goats had lesions in the respiratory tract. Mycoplasma ovipneumoniae was recovered from one of the animals four days after inoculation, but not at necropsy from any of the goats, at which time a marked humoral immune response with growth inhibiting antibodies was detected. In a second experiment three four to five week old goats were inoculated with the same strain and three other goats were given placebo treatment. One experimental goat developed fever and coughing, and it had extensive subacute fibrinous pleuritis in the right side and pneumonia. Another goat had focal pneumonia in the left diaphragmatic lobe. Microscopically there was subacute hyperplastic suppurative bronchiolitis, atelectasis and nonsuppurative alveolitis. The infected animals did not clear the mycoplasma and not all of them produced antibodies. Mycoplasma arginini, strain D53e, did not induce lesions in any of four goat kids within 14 days after inoculation but did cause transient elevations in rectal temperature, circulating monocytes, circulating neutrophils and blood fibrinogen. Mycoplasma arginini was infective and immunogenic for all inoculated animals and showed a particular affinity for the tonsil. Thus, this study provides the first evidence that M. ovipneumoniae is pathogenic for goats causing pneumonia and pleuritis.(ABSTRACT TRUNCATED AT 250 WORDS) Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:3742358

  15. A novel rapid DNA microarray assay enables identification of 37 Mycoplasma species and highlights multiple Mycoplasma infections.

    PubMed

    Schnee, Christiane; Schulsse, Samuel; Hotzel, Helmut; Ayling, Roger D; Nicholas, Robin A J; Schubert, Evelyn; Heller, Martin; Ehricht, Ralf; Sachse, Konrad

    2012-01-01

    Mycoplasmas comprise a conglomerate of pathogens and commensals occurring in humans and animals. The genus Mycoplasma alone contains more than 120 species at present, and new members are continuously being discovered. Therefore, it seems promising to use a single highly parallel detection assay rather than develop separate tests for each individual species. In this study, we have designed a DNA microarray carrying 70 oligonucleotide probes derived from the 23S rRNA gene and 86 probes from the tuf gene target regions. Following a PCR amplification and biotinylation step, hybridization on the array was shown to specifically identify 31 Mycoplasma spp., as well as 3 Acholeplasma spp. and 3 Ureaplasma spp. Members of the Mycoplasma mycoides cluster can be recognized at subgroup level. This procedure enables parallel detection of Mollicutes spp. occurring in humans, animals or cell culture, from mono- and multiple infections, in a single run. The main advantages of the microarray assay include ease of operation, rapidity, high information content, and affordability. The new test's analytical sensitivity is equivalent to that of real-time PCR and allows examination of field samples without the need for culture. When 60 field samples from ruminants and birds previously analyzed by denaturing-gradient gel electrophoresis (DGGE) were tested by the microarray assay both tests identified the same agent in 98.3% of the cases. Notably, microarray testing revealed an unexpectedly high proportion (35%) of multiple mycoplasma infections, i.e., substantially more than DGGE (15%). Two of the samples were found to contain four different Mycoplasma spp. This phenomenon deserves more attention, particularly its implications for epidemiology and treatment.

  16. Anatomic location of Mycoplasma mycoides subsp. capri and Mycoplasma agalactiae in naturally infected goat male auricular carriers.

    PubMed

    Gómez-Martín, Angel; De la Fe, Christian; Amores, Joaquín; Sánchez, Antonio; Contreras, Antonio; Paterna, Ana; Buendía, Antonio J; Corrales, Juan C

    2012-06-15

    This study sought to determine whether male goat auricular carriers of mycoplasmas known to cause contagious agalactia could harbour these microorganisms at anatomical sites other than the ears. A microbiological study was conducted in 6 naturally infected bucks that had been diagnosed as chronic auricular asymptomatic carriers of Mycoplasma (M.) mycoides subsp. capri (Mmc) more than one year previously. To detect mycoplasmas, cultures and PCR were performed on 46 samples taken from each goat from the cardio-respiratory, digestive, nervous, lymph and genitourinary systems and several joints. Of a total of 274 samples analyzed, 28 were positive for mycoplasmas (10.1%): Mmc was detected in 17 (6.1%), Mycoplasma (M.) agalactiae in 12 (4.3%) and both microorganisms were identified in one of the samples. In all 6 goats, mixed infection was observed despite none being auricular carriers of M. agalactiae. Mycoplasma spp. were identified at 15 different sites; the most frequent sites being the joints (31.2%, 5 positive samples), lymph nodes (25%, 4 positive samples) and respiratory tract (25%, 4 positive samples). Positive results were also obtained in three brain tissue (18.7%), two cardiac tissue (12.5%) and one ileum, urethra, testicle and bulbourethral gland (6.25%) samples. The histopathological findings may suggest the presence of mild chronic conditions in some of the organs where the bacteria were found. Our findings reveal for the first time the capacity of Mmc and M. agalactiae to colonize several other organ systems in chronically naturally infected auricular carriers, possibly representing an added risk factor for the spread of these microorganisms. In the case of M. agalactiae, colonization seemed to be independent of the animal's auricular carrier state.

  17. Nanotransformation of the haemotrophic Mycoplasma suis during in vitro cultivation attempts using modified cell free Mycoplasma media.

    PubMed

    Schreiner, Sabrina A; Hoelzle, Katharina; Hofmann-Lehmann, Regina; Hamburger, Anja; Wittenbrink, Max M; Kramer, Manuela M; Sokoli, Albina; Felder, Kathrin M; Groebel, Katrin; Hoelzle, Ludwig E

    2012-11-09

    Mycoplasma suis belongs to haemotrophic mycoplasmas (HMs) which cause infectious anaemia in a large variety of mammals. To date, no in vitro cultivation system for M. suis or other HMs has been established. We hypothesised that M. suis could grow in classical Mycoplasma media supplemented with nutrients (e.g. glucose, iron-binding proteins) which are naturally available from its host environment, the porcine blood. Blood from experimentally M. suis-infected pigs was used to inoculate either standard SP-4 Mycoplasma medium supplemented with iron-binding proteins (transferrin, haemin, and haemoglobin) or glucose-enriched Hayflick Mycoplasma medium. A quantitative M. suis-specific real-time PCR assay was applied to determine and quantify M. suis loads weekly during 12 week-incubation. The first 2 weeks after inoculation M. suis loads decreased remarkably and then persisted at a stationary level over the observation time of 12 weeks in iron-binding protein- or glucose supplemented media variants. Scanning electron microscopic analysis of liquid M. suis sub-cultures on Hayflick agar showed small, densely-packed microcolonies of irregular M. suis cells of reduced size (0.2-0.6μm) indicating nanotransformation. The partial 16S rDNA sequence of these cultured M. suis nanocells was 99.9% identical to M. suis. M. suis cells derived from liquid cultures interact in vitro with porcine erythrocytes by fibril-like structures. We conclude, that the modified Mycoplasma media used for M. suis cultivation are obviously unfavourable for growth but lead to culture persistence. M. suis adapt to inappropriate culture conditions by alteration into nanoforms.

  18. A Novel Rapid DNA Microarray Assay Enables Identification of 37 Mycoplasma Species and Highlights Multiple Mycoplasma Infections

    PubMed Central

    Schnee, Christiane; Schulsse, Samuel; Hotzel, Helmut; Ayling, Roger D.; Nicholas, Robin A. J.; Schubert, Evelyn; Heller, Martin; Ehricht, Ralf; Sachse, Konrad

    2012-01-01

    Mycoplasmas comprise a conglomerate of pathogens and commensals occurring in humans and animals. The genus Mycoplasma alone contains more than 120 species at present, and new members are continuously being discovered. Therefore, it seems promising to use a single highly parallel detection assay rather than develop separate tests for each individual species. In this study, we have designed a DNA microarray carrying 70 oligonucleotide probes derived from the 23S rRNA gene and 86 probes from the tuf gene target regions. Following a PCR amplification and biotinylation step, hybridization on the array was shown to specifically identify 31 Mycoplasma spp., as well as 3 Acholeplasma spp. and 3 Ureaplasma spp. Members of the Mycoplasma mycoides cluster can be recognized at subgroup level. This procedure enables parallel detection of Mollicutes spp. occurring in humans, animals or cell culture, from mono- and multiple infections, in a single run. The main advantages of the microarray assay include ease of operation, rapidity, high information content, and affordability. The new test's analytical sensitivity is equivalent to that of real-time PCR and allows examination of field samples without the need for culture. When 60 field samples from ruminants and birds previously analyzed by denaturing-gradient gel electrophoresis (DGGE) were tested by the microarray assay both tests identified the same agent in 98.3% of the cases. Notably, microarray testing revealed an unexpectedly high proportion (35%) of multiple mycoplasma infections, i.e., substantially more than DGGE (15%). Two of the samples were found to contain four different Mycoplasma spp. This phenomenon deserves more attention, particularly its implications for epidemiology and treatment. PMID:22479374

  19. Multiple ligand docking by Glide: implications for virtual second-site screening

    NASA Astrophysics Data System (ADS)

    Vass, Márton; Tarcsay, Ákos; Keserű, György M.

    2012-07-01

    Performance of Glide was evaluated in a sequential multiple ligand docking paradigm predicting the binding modes of 129 protein-ligand complexes crystallized with clusters of 2-6 cooperative ligands. Three sampling protocols (single precision—SP, extra precision—XP, and SP without scaling ligand atom radii—SP hard) combined with three different scoring functions (GlideScore, Emodel and Glide Energy) were tested. The effects of ligand number, docking order and druglikeness of ligands and closeness of the binding site were investigated. On average 36 % of all structures were reproduced with RMSDs lower than 2 Å. Correctly docked structures reached 50 % when docking druglike ligands into closed binding sites by the SP hard protocol. Cooperative binding to metabolic and transport proteins can dramatically alter pharmacokinetic parameters of drugs. Analyzing the cytochrome P450 subset the SP hard protocol with Emodel ranking reproduced two-thirds of the structures well. Multiple ligand binding is also exploited by the fragment linking approach in lead discovery settings. The HSP90 subset from real life fragment optimization programs revealed that Glide is able to reproduce the positions of multiple bound fragments if conserved water molecules are considered. These case studies assess the utility of Glide in sequential multiple docking applications.

  20. Transposon insertions in the Flavobacterium johnsoniae ftsX gene disrupt gliding motility and cell division.

    PubMed

    Kempf, M J; McBride, M J

    2000-03-01

    Flavobacterium johnsoniae is a gram-negative bacterium that exhibits gliding motility. To determine the mechanism of flavobacterial gliding motility, we isolated 33 nongliding mutants by Tn4351 mutagenesis. Seventeen of these mutants exhibited filamentous cell morphology. The region of DNA surrounding the transposon insertion in the filamentous mutant CJ101-207 was cloned and sequenced. The transposon was inserted in a gene that was similar to Escherichia coli ftsX. Two of the remaining 16 filamentous mutants also carried insertions in ftsX. Introduction of the wild-type F. johnsoniae ftsX gene restored motility and normal cell morphology to each of the three ftsX mutants. CJ101-207 appears to be blocked at a late stage of cell division, since the filaments produced cross walls but cells failed to separate. In E. coli, FtsX is thought to function with FtsE in translocating proteins involved in potassium transport, and perhaps proteins involved in cell division, into the cytoplasmic membrane. Mutations in F. johnsoniae ftsX may prevent translocation of proteins involved in cell division and proteins involved in gliding motility into the cytoplasmic membrane, thus resulting in defects in both processes. Alternatively, the loss of gliding motility may be an indirect result of the defect in cell division. The inability to complete cell division may alter the cell architecture and disrupt gliding motility by preventing the synthesis, assembly, or functioning of the motility apparatus.

  1. Dislocation dynamics simulations of interactions between gliding dislocations and radiation induced prismatic loops in zirconium

    NASA Astrophysics Data System (ADS)

    Drouet, Julie; Dupuy, Laurent; Onimus, Fabien; Mompiou, Frédéric; Perusin, Simon; Ambard, Antoine

    2014-06-01

    The mechanical behavior of Pressurized Water Reactor fuel cladding tubes made of zirconium alloys is strongly affected by neutron irradiation due to the high density of radiation induced dislocation loops. In order to investigate the interaction mechanisms between gliding dislocations and loops in zirconium, a new nodal dislocation dynamics code, adapted to Hexagonal Close Packed metals, has been used. Various configurations have been systematically computed considering different glide planes, basal or prismatic, and different characters, edge or screw, for gliding dislocations with -type Burgers vectors. Simulations show various interaction mechanisms such as (i) absorption of a loop on an edge dislocation leading to the formation of a double super-jog, (ii) creation of a helical turn, on a screw dislocation, that acts as a strong pinning point or (iii) sweeping of a loop by a gliding dislocation. It is shown that the clearing of loops is more favorable when the dislocation glides in the basal plane than in the prismatic plane explaining the easy dislocation channeling in the basal plane observed after neutron irradiation by transmission electron microscopy.

  2. Gliding resistance of flexor tendon associated with carpal tunnel pressure: a biomechanical cadaver study.

    PubMed

    Zhao, Chunfeng; Ettema, Anke M; Berglund, Lawrence J; An, Kai-Nan; Amadio, Peter C

    2011-01-01

    The purpose of this study was to investigate the effect of carpal tunnel pressure on the gliding characteristics of flexor tendons within the carpal tunnel. Eight fresh human cadaver wrists and hands were used. A balloon was inserted into the carpal tunnel to elevate the pressure. The mean gliding resistance of the middle finger flexor digitorum superficialis tendon was measured with the following six conditions: (1) as a baseline, before balloon insertion; (2) balloon with 0 mmHg pressure; (3) 30 mmHg; (4) 60 mmHg; (5) 90 mmHg; (6) 120 mmHg. The gliding resistance of flexor tendon gradually increased as the carpal tunnel pressure was elevated. At pressures above 60 mmHg, the increase in gliding resistance became significant compared to the baseline condition. This study helps us to understand the relationship between carpal tunnel pressure, which is elevated in the patient with carpal tunnel syndrome (CTS) and tendon gliding resistance, which is a component of the work of flexion. These findings suggest that patients with CTS may have to expend more energy to accomplish specific motions, which may in turn affect symptoms of hand pain, weakness and fatigue, seen commonly in such patients. Copyright © 2010 Orthopaedic Research Society.

  3. Gliding Resistance of Flexor Tendon Associated with Carpal Tunnel Pressure: A Biomechanical Cadaver Study

    PubMed Central

    Zhao, Chunfeng; Ettema, Anke M.; Berglund, Lawrence J.; An, Kai-Nan; Amadio, Peter C.

    2010-01-01

    The purpose of this study was to investigate the effect of carpal tunnel pressure on the gliding characteristics of flexor tendons within the carpal tunnel. Eight fresh human cadaver wrists and hands were used. A balloon was inserted into the carpal tunnel to elevate the pressure. The mean gliding resistance of the middle finger flexor digitorum superficialis tendon was measured with the following six conditions 1) as a baseline, before balloon insertion; 2) balloon with 0 mmHg pressure; 3) 30 mmHg; 4) 60 mmHg; 5) 90 mmHg; 6) 120 mmHg. The gliding resistance of flexor tendon gradually increased as the carpal tunnel pressure was elevated. At pressures above 60 mmHg, the increase in gliding resistance became significant compared to the baseline condition. This study helps us to understand the relationship between carpal tunnel pressure, which is elevated in the patient with carpal tunnel syndrome (CTS) and tendon gliding resistance, which is a component of the work of flexion. These findings suggest that patients with CTS may have to expend more energy to accomplish specific motions, which may in turn affect symptoms of hand pain, weakness and fatigue, seen commonly in such patients. PMID:20661935

  4. Identification of Mycoplasma bovigenitalium and Mycoplasma canadense from outbreaks of granulopapular vulvovaginitis in dairy cattle in Israel.

    PubMed

    Lysnyansky, I; Brenner, J; Alpert, N; Benjamin, A; Bernstein, M; Elad, D; Blum, S; Friedgut, O; Rotenberg, D

    2009-09-12

    A syndrome in which white foci and granulopustular lesions appeared on the vaginal mucous membranes of Holstein cows in several dairy herds in Israel is described. During clinical and diagnostic investigations, Mycoplasma bovigenitalium was isolated from 11 of 20 clinical cases. Vaginal swabs taken from the same cows yielded three isolates of Mycoplasma canadense, which were all associated with the M bovigenitalium infection. Two isolates of small, round, non-enveloped viral particles were approximately 25 nm in diameter and characteristic of enteroviruses on negative-staining electron microscopy.

  5. [Identification of species of Mycoplasma and Ureaplasma diversum from Argentinian dairy herds].

    PubMed

    Sosa, Camila; Tirante, Liliana; Chaves, Javier; Pol, Martín; Ambrogi, Arnaldo; Giraudo, José Angel; Tamiozzo, Pablo

    2017-09-27

    Several species of Mycoplasma and Ureaplasma diversum can cause diseases in dairy cattle, which can be associated or not with clinical manifestations. In our country, the presence of Mycoplasma bovis, Mycoplasma californicum and Mycoplasma canadense has been detected, being the only mycoplasma species identified so far. The objective of this study was to identify other species of the Mycoplasmataceae family. Thirty-five Mycoplasma spp.-like isolates obtained from different samples from cattle, with or without clinical symptoms, from eight herds located in the provinces of Santa Fe, Cordoba, Buenos Aires and San Luis were utilized in the present study. Through the use of species-specific polymerase chain reactions (PCR) Mycoplasma bovigenitalium, Mycoplasma alkalescens, Mycoplasma bovirhinis and U. diversum were identified and through amplification and further sequencing of the 16-23S rRNA intergenic spacer regions, Mycoplasma arginine and M. californicum were identified. The identification of these species represents an important advance in knowledge in order to include these pathogens in the differential diagnosis of certain clinical and pathological entities of cattle from Argentina. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Investigations of Lateral Stability of a Glide Bomb Using Automatic Control Having No Time Lag

    NASA Technical Reports Server (NTRS)

    Sponder, E. W.

    1950-01-01

    The investigation of the lateral stability of an automatically controlled glide bomb led also to the attempt of clarifying the influence of a phugoid oscillation or of any general longitudinal oscillation on the lateral stability of a glide bomb. Under the assumption that its period of oscillation considerably exceeds the rolling and yawing oscillation and that c(sub a) is, at least in sections, practically constant, the result of this test is quite simple. It becomes clear that the influence of the phugoid oscillation may be replaced by suitable variation of the rolling-yawing moment on a rectilinear flight path instead of the phugoid oscillation. If the flying weight of the glide bomb of unchanged dimensions is increased, an increase of the flight velocity will be more favorable than an increase of the lift coefficient. The arrangement of the control permits lateral stability to be achieved in every case; a minimum rolling moment due to sideslip proves of great help.

  7. Dynamic and spectroscopic characteristics of atmospheric gliding arc in gas-liquid two-phase flow

    NASA Astrophysics Data System (ADS)

    Tu, X.; Yu, L.; Yan, J. H.; Cen, K. F.; Chéron, B. G.

    2009-11-01

    In this study, an atmospheric alternating-current gliding arc device in gas-liquid two-phase flow has been developed for the purpose of waste water degradation. The dynamic behavior of the gas-liquid gliding arc is investigated through the oscillations of electrical signals, while the spatial evolution of the arc column is analyzed by high speed photography. Different arc breakdown regimes are reported, and the restrike mode is identified as the typical fluctuation characteristic of the hybrid gliding arc in air-water mixture. Optical emission spectroscopy is employed to investigate the active species generated in the gas-liquid plasma. The axial evolution of the OH (309 nm) intensity is determined, while the rotational and vibrational temperatures of the OH are obtained by a comparison between the experimental and simulated spectra. The significant discrepancy between the rotational and translational temperatures has also been discussed.

  8. Two-leg Su-Schrieffer-Heeger chain with glide reflection symmetry

    NASA Astrophysics Data System (ADS)

    Zhang, Shao-Liang; Zhou, Qi

    2017-06-01

    The Su-Schrieffer-Heeger (SSH) model lays the foundation of many important concepts in quantum topological matters. Here, we show that a spin-dependent double-well optical lattice allows one to couple two topologically distinct SSH chains in the bulk and realize a glided-two-leg SSH model that respects the glide reflection symmetry. Such a model gives rise to intriguing quantum phenomena beyond the paradigm of a traditional SSH model. It is characterized by Wilson lines that require non-Abelian Berry connections, and the interplay between the glide symmetry and interaction automatically leads to charge fractionalization without jointing two lattice potentials at an interface. Our work demonstrates the versatility of ultracold atoms to create new theoretical models for studying topological matters.

  9. Effect of 2H and 18O water isotopes in kinesin-1 gliding assay

    PubMed Central

    Herskowitz, Lawrence J.; Koch, Steven J.

    2014-01-01

    We show for the first time the effects of heavy-hydrogen water (2H2O) and heavy-oxygen water (H218O) on the gliding speed of microtubules on kinesin-1 coated surfaces. Increased fractions of isotopic waters used in the motility solution decreased the gliding speed of microtubules by a maximum of 21% for heavy-hydrogen and 5% for heavy-oxygen water. We also show that gliding microtubule speed returns to its original speed after being treated with heavy-hydrogen water. We discuss possible interpretations of these results and the importance for future studies of water effects on kinesin and microtubules. We also discuss the implication for using heavy waters in biomolecular devices incorporating molecular motors. PMID:24711961

  10. Classification and surface anomaly of glide symmetry protected topological phases in three dimensions

    NASA Astrophysics Data System (ADS)

    Lu, Fuyan; Shi, Bowen; Lu, Yuan-Ming

    2017-07-01

    We study glide protected topological (GSPT) phases of interacting bosons and fermions in three spatial dimensions with certain on-site symmetries. They are crystalline SPT phases, which are distinguished from a trivial product state only in the presence of non-symmorphic glide symmetry. We classify these GSPT phases with various on-site symmetries such as U(1) and time reversal, and show that they can all be understood by stacking and coupling two-dimensional (2D) short-range-entangled phases in a glide-invariant way. Using such a coupled layer construction we study the anomalous surface topological orders of these GSPT phases, which gap out the 2D surface states without breaking any symmetries. While this framework can be applied to any non-symmorphic SPT phase, we demonstrate it in many examples of GSPT phases including the non-symmorphic topological insulator with ‘hourglass fermion’ surface states.

  11. Control of Mycoplasma hyopneumoniae infections in pigs.

    PubMed

    Maes, D; Segales, J; Meyns, T; Sibila, M; Pieters, M; Haesebrouck, F

    2008-01-25

    Mycoplasma hyopneumoniae, the primary pathogen of enzootic pneumonia, occurs worldwide and causes major economic losses to the pig industry. The organism adheres to and damages the ciliated epithelium of the respiratory tract. Affected pigs show chronic coughing, are more susceptible to other respiratory infections and have a reduced performance. Control of the disease can be accomplished in a number of ways. First, management practices and housing conditions in the herd should be optimized. These include all-in/all-out production, limiting factors that may destabilize herd immunity, maintaining optimal stocking densities, prevention of other respiratory diseases, and optimal housing and climatic conditions. Strategic medication with antimicrobials active against M. hyopneumoniae and, preferably, also against major secondary bacteria may be useful during periods when the pigs are at risk for respiratory disease. Finally, commercial bacterins are widely used to control M. hyopneumoniae infections. The main effects of vaccination include less clinical symptoms, lung lesions and medication use, and improved performance. However, bacterins provide only partial protection and do not prevent colonization of the organism. Different vaccination strategies (timing of vaccination, vaccination of sows, vaccination combined with antimicrobial medication) can be used, depending on the type of herd, the production system and management practices, the infection pattern and the preferences of the pig producer. Research on new vaccines is actively occurring, including aerosol and feed-based vaccines as well as subunit and DNA vaccines. Eradication of the infection at herd level based on age-segregation and medication is possible, but there is a permanent risk for re-infections.

  12. 21 CFR 864.2360 - Mycoplasma detection media and components.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mycoplasma detection media and components. 864.2360 Section 864.2360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Cell And Tissue Culture...

  13. In Vitro Susceptibilities of Mycoplasma hyopneumoniae Field Isolates

    PubMed Central

    Vicca, J.; Stakenborg, T.; Maes, D.; Butaye, P.; Peeters, J.; de Kruif, A.; Haesebrouck, F.

    2004-01-01

    The in vitro susceptibilities of 21 Mycoplasma hyopneumoniae field isolates were determined using a broth microdilution technique. One isolate showed acquired resistance to lincomycin, tilmicosin, and tylosin, while five isolates were resistant to flumequine and enrofloxacin. Acquired resistance against these antimicrobials in M. hyopneumoniae field isolates was not reported previously. PMID:15504886

  14. 9 CFR 113.408 - Avian mycoplasma antigen.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ion concentration, purity, sensitivity, and specificity in accordance with the conditions prescribed... shall be tested for viable bacteria and fungi as prescribed in § 113.26. (f) Sensitivity requirements...) The sensitivity of Mycoplasma Gallisepticum Antigen shall be tested using a set of chicken and a set...

  15. Atypical pneumonia associated with a Mycoplasma isolate in a kitten.

    PubMed

    Bongrand, Yannick; Blais, Marie-Claude; Alexander, Kate

    2012-10-01

    An atypical case of Mycoplasma pneumonia with an unusual radiographic and computed tomographic pattern was diagnosed in a Siamese kitten. The cat showed no response to broad-spectrum antibiotic therapy including enrofloxacin. The administration of doxycycline led to a dramatic clinical and radiographic improvement.

  16. Interaction of Mycoplasma dispar with bovine alveolar macrophages.

    PubMed Central

    Almeida, R A; Wannemuehler, M J; Rosenbusch, R F

    1992-01-01

    The capacity to avoid phagocytosis and the activation of bovine alveolar macrophages (BAM) by encapsulated Mycoplasma dispar or purified M. dispar capsule was investigated. Encapsulated and unencapsulated M. dispar were cocultured with BAM in the presence or absence of antisera prepared against unencapsulated M. dispar or purified capsule antiserum. Unopsonized mycoplasmas resisted phagocytosis, while only anti-capsule antibodies enhanced the phagocytosis of encapsulated mycoplasmas. BAM were cultured in the presence of purified M. dispar capsule or either live or heat-killed encapsulated or unencapsulated M. dispar. These BAM were then activated with Escherichia coli endotoxin or left without further activation. The supernatants of these cultures were assayed for tumor necrosis factor, interleukin 1, and glucose consumption as indicators of macrophage activation. Tumor necrosis factor and interleukin 1 were produced by BAM stimulated with unencapsulated M. dispar but not when encapsulated M. dispar or its purified capsule was used. Similarly, glucose consumption was increased in the presence of unencapsulated M. dispar, but not when BAM were cocultured with encapsulated M. dispar or purified capsule. When BAM were treated with purified capsule or encapsulated mycoplasmas, they could not be subsequently activated by endotoxin. These results indicate that encapsulated M. dispar or purified capsule exerts an inhibitory effect on the activity of BAM and prevents the activation of these cells. PMID:1612758

  17. 21 CFR 610.30 - Test for Mycoplasma.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Test for Mycoplasma. 610.30 Section 610.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS... Methylene Blue-Azure dye or an equivalent staining procedure is used, no less than a one square cm. plug...

  18. 21 CFR 610.30 - Test for Mycoplasma.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Test for Mycoplasma. 610.30 Section 610.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS... Methylene Blue-Azure dye or an equivalent staining procedure is used, no less than a one square cm. plug...

  19. Stability of rehydrated Mycoplasma gallisepticum vaccine homogeneity over time

    USDA-ARS?s Scientific Manuscript database

    Proper vaccine application is required to maximize the results of the vaccination, with maintenance of a homogenous solution is critical to obtain uniform results. This study was designed to analyze the need for continued mixing of a Mycoplasma gallisepticum vaccine solution in order to maintain a ...

  20. Proteomic analysis of Mycoplasma gallisepticum vaccine strain F

    USDA-ARS?s Scientific Manuscript database

    The persistence and displacement abilities of the Mycoplasma gallisepticum vaccine strain F (F-strain) are well documented. Understanding the mechanism(s) of colonization and persistence of F-strain will aid in the current intervention strategies to diagnose and control MG infections in poultry. In ...

  1. High Prevalence of Mycoplasma faucium DNA in the Human Oropharynx.

    PubMed

    Edouard, Sophie; Courtois, Gaëlle Denis; Gautret, Philippe; Jouve, Jean-Luc; Minodier, Philippe; Noël, Guilhem; Roch, Antoine; Brouqui, Philippe; Stein, Andreas; Drancourt, Michel; Fournier, Pierre-Edouard; Raoult, Didier

    2016-01-01

    Mycoplasma faucium has recently been associated with brain abscesses and seems to originate from the mouth. We evaluated its prevalence by quantitative real-time PCR (qPCR) in the oropharynxes of 644 subjects and found that 25% harbored M. faucium, probably constituting the gateway for entrance of the bacteria into cerebral abscesses.

  2. Methyl-prednisolone in neurologic complications of Mycoplasma pneumonia.

    PubMed

    Gücüyener, K; Simşek, F; Yilmaz, O; Serdaroğlu, A

    2000-06-01

    In patients with Mycoplasma pneumonia extrapulmonary manifestations such as encephalitis, meningitis, cerebellar and brain stem involvement, cranial nerve lesions, peripheral neuropathy, polymyositis have been observed. We report a 16-year-old girl with M. pneumonia infection, acute behavioral changes and coma. Treatment with high dose methyl-prednisolone and clarithromycin led to rapid clinical improvement.

  3. Cranial neuropathy, myeloradiculopathy, and myositis: complications of Mycoplasma pneumoniae infection.

    PubMed

    Rothstein, T L; Kenny, G E

    1979-08-01

    Polymyositis, transverse myelitis, ascending polyneuritis, bilateral optic neuritis, and hearing loss developed in a patient with high complement-fixing antibody titers to Mycoplasma pneumoniae. Each of her three children had primary atypical pneumonia with isolation of the organism. The neurologic disturbance is thought to represent a postinfectious complication of M pneumoniae infection.

  4. Isolation of Mycoplasma hyosynoviae from pneumonic lung of swine.

    PubMed

    Dahlia, H; Tan, L J; Zarrahimah, Z; Maria, J

    2009-12-01

    The isolation of Mycoplasma hyosynoviae from a piglet with severe pneumonia is described. This is the first report of M. hyosynoviae isolation in the country. The lung sample where the isolation was made was severely consolidated, suppurative and pleurisy. The pathogenicity of the M. hyosynoviae isolated has yet to be determined.

  5. High Prevalence of Mycoplasma faucium DNA in the Human Oropharynx

    PubMed Central

    Edouard, Sophie; Courtois, Gaëlle Denis; Gautret, Philippe; Jouve, Jean-Luc; Minodier, Philippe; Noël, Guilhem; Roch, Antoine; Brouqui, Philippe; Stein, Andreas; Drancourt, Michel; Fournier, Pierre-Edouard

    2015-01-01

    Mycoplasma faucium has recently been associated with brain abscesses and seems to originate from the mouth. We evaluated its prevalence by quantitative real-time PCR (qPCR) in the oropharynxes of 644 subjects and found that 25% harbored M. faucium, probably constituting the gateway for entrance of the bacteria into cerebral abscesses. PMID:26511735

  6. Ureaplasma urealyticum, Mycoplasma hominis and adverse pregnancy outcomes.

    PubMed

    Capoccia, Romina; Greub, Gilbert; Baud, David

    2013-06-01

    Mycoplasma hominis and Ureaplasma urealyticum may colonize the human genital tract and have been associated with adverse pregnancy outcomes. Chorioamnionitis, spontaneous preterm labour and preterm premature rupture of membranes are significant contributors to neonatal morbidity and mortality. However, as these bacteria can reside in the normal vaginal flora, there are controversies regarding their true role during pregnancy and thus the need to treat these organisms. We review here the recent data on the epidemiology of mycoplasmas and their clinical role during pregnancy. The association of these organisms with preterm labour has been suggested by many observational studies, but proof of causality remains limited. PCR is an excellent alternative to culture to detect the presence of these organisms, but culture allows antibiotic susceptibility testing. Whether antimicrobial treatment of mycoplasma-colonized pregnant patients can effectively reduce the incidence of adverse pregnancy outcomes warrants further investigations. The role of Mycoplasma spp. and U. urealyticum in adverse pregnancy outcomes is increasingly accepted. However, sole presence of these microorganisms in the vaginal flora might be insufficient to cause pathological issues, but their combination with other factors such as bacterial vaginosis or cervical incompetence may be additionally needed to induce preterm birth.

  7. Rhabdomyolysis associated with antimicrobial drug-resistant Mycoplasma pneumoniae.

    PubMed

    Oishi, Tomohiro; Narita, Mitsuo; Ohya, Hitomi; Yamanaka, Takayuki; Aizawa, Yuta; Matsuo, Mai; Matsunaga, Masamichi; Tsukano, Shinya; Taguchi, Testuo

    2012-05-01

    We describe a case of rhabdomyolysis in a patient infected with antimicrobial drug-resistant Mycoplasma pneumoniae The patient's acute-phase serum levels of interleukin-18 and tumor necrosis factor-α were high, which suggests a pathogenic role for M. pneumoniae. In an era of increasing antimicrobial drug resistance, a system for rapidly identifying resistant M. pneumoniae would be beneficial.

  8. Mycoplasma mastitis in cattle: To cull or not to cull.

    PubMed

    Nicholas, Robin A J; Fox, Larry K; Lysnyansky, Inna

    2016-10-01

    Bovine mastitis caused by mycoplasmas, in particular Mycoplasma bovis, is a major problem for milk production and animal welfare in large dairy herds in the USA and a serious, although sporadic, disease in Europe and the Middle East. It causes severe damage to the udder of cattle and is largely untreatable by chemotherapy. Mycoplasma mastitis has a distinct epidemiology and a unique set of risk factors, the most important of which is large herd size. The disease is often self-limiting, disappearing within months of outbreaks, sometimes without deliberate intervention. Improved molecular diagnostic tests are leading to more rapid detection of mycoplasmas. Typing tests, such as multi-locus sequence typing, can help trace the source of outbreaks. An approach to successful control is proposed, which involves regular monitoring and rapid segregation or culling of infected cows. Serious consideration should be given by owners of healthy dairy herds to the purchase of M. bovis-free replacements. Increased cases of disease could occur in Europe and Israel if the trend for larger dairy herds continues. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Macrolide susceptibility of Mycoplasma hyorhinis isolated from piglets.

    PubMed Central

    Kobayashi, H; Morozumi, T; Munthali, G; Mitani, K; Ito, N; Yamamoto, K

    1996-01-01

    Twenty strains of Mycoplasma hyorhinis were investigated for their in vitro susceptibilities to 15 antimicrobial agents by broth and agar dilution methods. Two of the 20 field strains showed low susceptibility to 14- and 16-membered macrolide antimicrobial agents tested. The two field strains were considered inducibly resistant to macrolides. PMID:8849222

  10. Mycoplasma bovis: an emerging pathogen of ranched bison

    USDA-ARS?s Scientific Manuscript database

    Mycoplasma bovis (M. bovis) is an emerging, primary pathogen of ranched bison (Bison bison) in North America. It causes severe disease among animals in feedlots as well as breeding-age cows and bulls on pasture. Mortality in adult bison is as high as 25 percent, resulting in significant economic l...

  11. 9 CFR 113.408 - Avian mycoplasma antigen.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Avian mycoplasma antigen. 113.408 Section 113.408 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... with a dye acceptable to Animal and Plant Health Inspection Service (APHIS). Final container samples of...

  12. 9 CFR 113.408 - Avian mycoplasma antigen.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Avian mycoplasma antigen. 113.408 Section 113.408 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... with a dye acceptable to Animal and Plant Health Inspection Service (APHIS). Final container samples of...

  13. CO2 conversion in a gliding arc plasma: 1D cylindrical discharge model

    NASA Astrophysics Data System (ADS)

    Wang, Weizong; Berthelot, Antonin; Kolev, Stanimir; Tu, Xin; Bogaerts, Annemie

    2016-12-01

    CO2 conversion by a gliding arc plasma is gaining increasing interest, but the underlying mechanisms for an energy-efficient process are still far from understood. Indeed, the chemical complexity of the non-equilibrium plasma poses a challenge for plasma modeling due to the huge computational load. In this paper, a one-dimensional (1D) gliding arc model is developed in a cylindrical frame, with a detailed non-equilibrium CO2 plasma chemistry set, including the CO2 vibrational kinetics up to the dissociation limit. The model solves a set of time-dependent continuity equations based on the chemical reactions, as well as the electron energy balance equation, and it assumes quasi-neutrality in the plasma. The loss of plasma species and heat due to convection by the transverse gas flow is accounted for by using a characteristic frequency of convective cooling, which depends on the gliding arc radius, the relative velocity of the gas flow with respect to the arc and on the arc elongation rate. The calculated values for plasma density and plasma temperature within this work are comparable with experimental data on gliding arc plasma reactors in the literature. Our calculation results indicate that excitation to the vibrational levels promotes efficient dissociation in the gliding arc, and this is consistent with experimental investigations of the gliding arc based CO2 conversion in the literature. Additionally, the dissociation of CO2 through collisions with O atoms has the largest contribution to CO2 splitting under the conditions studied. In addition to the above results, we also demonstrate that lumping the CO2 vibrational states can bring a significant reduction of the computational load. The latter opens up the way for 2D or 3D models with an accurate description of the CO2 vibrational kinetics.

  14. Cruising the rain forest floor: butterfly wing shape evolution and gliding in ground effect.

    PubMed

    Cespedes, Ann; Penz, Carla M; DeVries, Philip J

    2015-05-01

    Flight is a key innovation in the evolutionary success of insects and essential to dispersal, territoriality, courtship and oviposition. Wing shape influences flight performance and selection likely acts to maximize performance for conducting essential behaviours that in turn results in the evolution of wing shape. As wing shape also contributes to fitness, optimal shapes for particular flight behaviours can be assessed with aerodynamic predictions and placed in an ecomorphological context. Butterflies in the tribe Haeterini (Nymphalidae) are conspicuous members of understorey faunas in lowland Neotropical forests. Field observations indicate that the five genera in this clade differ in flight height and behaviour: four use gliding flight at the forest floor level, and one utilizes flapping flight above the forest floor. Nonetheless, the association of ground level gliding flight behaviour and wing shape has never been investigated in this or any other butterfly group. We used landmark-based geometric morphometrics to test whether wing shapes in Haeterini and their close relatives reflected observed flight behaviours. Four genera of Haeterini and some distantly related Satyrinae showed significant correspondence between wing shape and theoretical expectations in performance trade-offs that we attribute to selection for gliding in ground effect. Forewing shape differed between sexes for all taxa, and male wing shapes were aerodynamically more efficient for gliding flight than corresponding females. This suggests selection acts differentially on male and female wing shapes, reinforcing the idea that sex-specific flight behaviours contribute to the evolution of sexual dimorphism. Our study indicates that wing shapes in Haeterini butterflies evolved in response to habitat-specific flight behaviours, namely gliding in ground effect along the forest floor, resulting in ecomorphological partitions of taxa in morphospace. The convergent flight behaviour and wing morphology

  15. Mycoplasmas isolated from the respiratory tract of horses.

    PubMed Central

    Allam, N. M.; Lemcke, R. M.

    1975-01-01

    Ten mycoplasmas were isolated from 130 nasopharyngeal swabs from thoroughbred horses with acute respiratory disease and three from 198 apparently normal horses. Two mycoplasmas were isolated from 21 tracheal swabs taken at necropsy. These mycoplasmas, together with six isolated from the equine respiratory tract by other workers, were subjected to biochemical and serological tests. Other properties examined in certain representative strains were appearance under the electron microscope, ability to adsorb or agglutinate the erythrocytes of various animal species and the electrophoretic pattern of the cell proteins. On the basis of these test, mycoplasmas from the equine respiratory tract were divided into seven species. Three species belonged to the genus Acholeplasma, members of which do not require sterol for growth, and were identified as A. laidlawii, A. oculi (formerly A. oculusi) originally isolated from the eyes of goats, and a recently named species A. equifoetale, previously isolated from aborted equine fetuses. Of the four sterol-dependent Mycoplasma species, one was indentified as M. pulmonis, a common rodent pathogen. Another cross-reacted serologically with M. felis and should probably be classified as that species. The other two species probably represent new species peculiar to the horse. One of these, represented by the strains N3 and N11, ferments glucose and is serologically distinct from 19 recognized species of glucose-utilizing mycoplasmas and from two species which do not metabolize either glucose or arginine. The other species, represented by four strains, hydrolyses arginine and, because it is serologically distinct from all the named arginine-hydrolysing Mycoplasma species, the name M. equirhinis sp.nov. is proposed for it. Of the seven species, only M. pulmonis and the glucose-utilizing species represented by N3 and N11 were found exclusively in horses with acute respiratory disease. A. oculi was isolated from an apparently normal horse. The

  16. Enumeration, isolation, and species identification of mycoplasmas in saliva sampled from the normal and pathological human oral cavity and antibody response to an oral mycoplasma (Mycoplasma salivarium).

    PubMed

    Watanabe, T; Matsuura, M; Seto, K

    1986-06-01

    Saliva samples collected from 393 subjects with and without oral diseases were examined for concentrations of mycoplasmas and Mycoplasma species. Mycoplasmas were isolated from 383 (97%) of the 393 subjects. Viable counts ranged from zero to 7.6 X 10(7) CFU/ml (median, 6.9 X 10(4)) and were significantly (P less than 0.01) higher in diseased subjects, except for those with arthrosis temporomandibularis, than in controls. Of 1,400 isolates, 897 (64%), 442 (30%), and 8 (1%) were identified as Mycoplasma salivarium, M. orale, and M. hominis, respectively, and the remaining 73 isolates (5%) were unidentifiable. More than two-thirds of the isolates from diseased subjects versus only half from controls were identified as M. salivarium. In diseased subjects other than those with ostitis (especially those with arthrosis temporomandibularis), the incidence of M. salivarium was higher than that of M. orale, whereas the former occurred about as frequently as the latter in the controls. Antibodies to M. salivarium were also measured in sera from some subjects by the metabolism inhibition test. Sera with metabolism inhibition titers of 16 or greater were rated positive. There was no significant difference in the prevalence of antibodies between diseased subjects (60%) and controls (40%), but the mean titers (97 to 220) of all positive sera from diseased subjects were two to four times those for sera from controls. In addition, a fourfold or greater rise or fall of antibody titers to the organism was shown in paired sera from some subjects. On the basis of these results, M. salivarium was strongly suggested to participate etiologically in some cases of oral infection.

  17. Enumeration, isolation, and species identification of mycoplasmas in saliva sampled from the normal and pathological human oral cavity and antibody response to an oral mycoplasma (Mycoplasma salivarium).

    PubMed Central

    Watanabe, T; Matsuura, M; Seto, K

    1986-01-01

    Saliva samples collected from 393 subjects with and without oral diseases were examined for concentrations of mycoplasmas and Mycoplasma species. Mycoplasmas were isolated from 383 (97%) of the 393 subjects. Viable counts ranged from zero to 7.6 X 10(7) CFU/ml (median, 6.9 X 10(4)) and were significantly (P less than 0.01) higher in diseased subjects, except for those with arthrosis temporomandibularis, than in controls. Of 1,400 isolates, 897 (64%), 442 (30%), and 8 (1%) were identified as Mycoplasma salivarium, M. orale, and M. hominis, respectively, and the remaining 73 isolates (5%) were unidentifiable. More than two-thirds of the isolates from diseased subjects versus only half from controls were identified as M. salivarium. In diseased subjects other than those with ostitis (especially those with arthrosis temporomandibularis), the incidence of M. salivarium was higher than that of M. orale, whereas the former occurred about as frequently as the latter in the controls. Antibodies to M. salivarium were also measured in sera from some subjects by the metabolism inhibition test. Sera with metabolism inhibition titers of 16 or greater were rated positive. There was no significant difference in the prevalence of antibodies between diseased subjects (60%) and controls (40%), but the mean titers (97 to 220) of all positive sera from diseased subjects were two to four times those for sera from controls. In addition, a fourfold or greater rise or fall of antibody titers to the organism was shown in paired sera from some subjects. On the basis of these results, M. salivarium was strongly suggested to participate etiologically in some cases of oral infection. PMID:3711294

  18. GlideScope versus flexible fiber optic for awake upright laryngoscopy.

    PubMed

    Silverton, Natalie A; Youngquist, Scott T; Mallin, Michael P; Bledsoe, Joseph R; Barton, Erik D; Schroeder, Erika D; Bledsoe, Amber D; Axelrod, Deborah A

    2012-03-01

    We compare laryngoscopic quality and time to highest-grade view between a face-to-face approach with the GlideScope and traditional flexible fiber-optic laryngoscopy in awake, upright volunteers. This was a prospective, randomized, crossover study in which we performed awake laryngoscopy under local anesthesia on 23 healthy volunteers, using both a GlideScope video laryngoscopy face-to-face technique with the blade held upside down and flexible fiber-optic laryngoscopy. Operator reports of Cormack-Lehane laryngoscopic views and video-reviewed time to highest-grade view, as well as number of attempts, were recorded. Ten women and 13 men participated. A grade II or better view was obtained with GlideScope video laryngoscopy in 22 of 23 (95.6%) participants and in 23 of 23 (100%) participants with flexible fiber-optic laryngoscopy (relative risk GlideScope video laryngoscopy versus flexible fiber-optic laryngoscopy 0.96; 95% confidence interval 0.88 to 1.04). Median time to highest-grade view for GlideScope video laryngoscopy was 16 seconds (interquartile range 9 to 34) versus 51 seconds (interquartile range 35 to 96) for flexible fiber-optic laryngoscopy. A distribution of interindividual differences demonstrated that GlideScope video laryngoscopy was, on average, 39 seconds faster than flexible fiber-optic laryngoscopy (95% confidence interval 0.2 to 76.9 seconds). GlideScope video laryngoscopy can be used to obtain a Cormack-Lehane grade II or better view in the majority of awake, healthy volunteers when an upright face-to-face approach is used and was slightly faster than traditional flexible fiber-optic laryngoscopy. However, flexible fiber-optic laryngoscopy may be more reliable at obtaining high-grade views of the larynx. Awake, face-to-face GlideScope use may offer an alternative approach to the difficulty airway, particularly among providers uncomfortable with flexible fiber-optic laryngoscopy. Copyright © 2011 American College of Emergency Physicians

  19. Aerodynamic performance due to forewing and hindwing interaction in gliding dragonfly flight.

    PubMed

    Zhang, Jie; Lu, Xi-Yun

    2009-07-01

    Aerodynamic performance due to forewing and hindwing interaction in gliding dragonfly flight has been studied using a multiblock lattice Boltzmann method. We find that the interactions between forewing and hindwing effectively enhance the total lift force and reduce the drag force on the wings compared to two independent wings. The interaction mechanism may be associated with the triangular camber effect by modulating the relative arrangement of the forewing and hindwing. The results obtained in this Brief Report provide physical insight into the understanding of aerodynamic behaviors for gliding dragonfly flight.

  20. Phospholipid composition of gliding bacteria: oral isolates of Capnocytophaga compared with Sporocytophaga.

    PubMed Central

    Holt, S C; Doundowlakis, J; Takacs, B J

    1979-01-01

    The distribution of acetone-soluble (neutral glycolipid) and acetone-insoluble (phospholipid isoprenoids) lipids in oral isolates of gram-negative gliding bacteria of the genus Capnocytophaga was compared with those in a non-host-related gliding bacterium, Sporocytophaga myxococcoides. The acetone-soluble material accounted for 34 to 55% of the extracted lipids; the remainder was acetone-insoluble material. The major phospholipid was phosphatidylethanolamine (67%), with lesser amounts of lysophosphatidylethanolamine and several unidentified phosphate-containing compounds. Capnocytophaga also contained significant amounts of an ornithine-amino lipid. PMID:500209

  1. Gliding arc surface modification of carrot nanofibre coating - perspective for composite processing

    NASA Astrophysics Data System (ADS)

    Kusano, Y.; Berglund, L.; Aitomäki, Y.; Oksman, K.; Madsen, B.

    2016-07-01

    Surfaces of carrot nanofibre coatings were modified by a gliding arc in atmospheric pressure air. The treatment strengthened wetting of deionized water and glycerol, increased an oxygen content, C-O and C=O, and moderately roughened the surfaces. In the perspective of composite materials, these changes to the nanofibres can potentially improve their processability when they are to be impregnated with a polymeric matrix. However, longer exposure to the gliding arc reduced oxidation and roughness of the surface, and thus there exists an optimum condition to achieve good wetting to solvents.

  2. Transcriptome Changes in Mycoplasma hyopneumoniae during Infection▿ †

    PubMed Central

    Madsen, Melissa L.; Puttamreddy, Supraja; Thacker, Eileen L.; Carruthers, Michael D.; Minion, F. Chris

    2008-01-01

    Mycoplasma hyopneumoniae causes swine pneumonia and contributes significantly to the porcine respiratory disease complex. The mechanisms of pathogenesis are difficult to address, since there is a lack of genetic tools, but microarrays are available and can be used to study transcriptional changes that occur during disease as a way to identify important virulence-related genes. Mycoplasmas were collected from bronchial alveolar lavage samples and compared to broth-grown cells using microarrays. Bronchial alveolar lavage was performed on pigs 28 days postinfection, and mycoplasmas were isolated by differential centrifugation. Mycoplasma RNA-enriched preparations were then obtained from total RNA by subtracting eucaryotic ribosomal and messenger RNAs. Labeled cDNAs were generated with mycoplasma open reading frame-specific primers. Nine biological replicates were analyzed. During lung infection, our analysis indicated that 79 M. hyopneumoniae genes were differentially expressed (P < 0.01), at a false-discovery rate of <2.7%. Of the down-regulated genes, 28 of 46 (61%) lacked an assigned function, in comparison to 21 of 33 (63%) of up-regulated genes. Four down-regulated genes and two up-regulated genes encoded putative lipoproteins. secA (mhp295) (P = 0.003) and two glycerol transport permease genes (potA [mhp380; P = 0.006] and ugpA [mhp381; P = 0.003]) were up-regulated in vivo. Elongation factor EF-G (fusA [mhp083]) (P = 0.002), RNA polymerase beta chain (rpoC [mhp635]) (P = 0.003), adenylate kinase (adk [mhp208]) (P = 0.001), prolyl aminoacyl tRNA synthetase (proS [mhp397]) (P = 0.009), and cysteinyl-tRNA synthetase (cysS [mhp661]) (P < 0.001) were down-regulated in vivo. PMID:18070898

  3. Remarkable increase in fluoroquinolone-resistant Mycoplasma genitalium in Japan.

    PubMed

    Kikuchi, Mina; Ito, Shin; Yasuda, Mitsuru; Tsuchiya, Tomohiro; Hatazaki, Kyoko; Takanashi, Masaki; Ezaki, Takayuki; Deguchi, Takashi

    2014-09-01

    We determined the prevalence of macrolide and fluoroquinolone resistance-associated mutations in Mycoplasma genitalium DNA specimens from men with non-gonococcal urethritis (NGU) and analysed their effects on antibiotic treatments of M. genitalium infections. In this retrospective study, we examined antibiotic resistance-associated mutations in the 23S rRNA, gyrA and parC genes of M. genitalium and the association of the mutations with microbiological outcomes of antibiotic treatments in men with M. genitalium-positive NGU. No macrolide resistance-associated mutations in the 23S rRNA gene were observed in 27 M. genitalium DNA specimens in 2011 and in 24 in 2012. However, 5 of 17 in 2013 had 23S rRNA mutations. Three of 15 in 2011, 6 of 19 in 2012 and 8 of 17 in 2013 had fluoroquinolone resistance-associated alterations in ParC. Three in 2013 had both the antibiotic resistance-associated alterations coincidentally. In two men with M. genitalium harbouring 23S rRNA mutations, the mycoplasma persisted after treatment with a regimen of 2 g of extended-release azithromycin (AZM-SR) once daily for 1 day. All nine men with mycoplasma harbouring ParC alterations were microbiologically cured with a regimen of 100 mg of sitafloxacin twice daily for 7 days. Macrolide- or fluoroquinolone-resistant M. genitalium appears to be increasing, and the increase in fluoroquinolone-resistant mycoplasmas is especially remarkable in Japan. Mycoplasmas harbouring 23S rRNA mutations would be resistant to the AZM-SR regimen, but those harbouring ParC alterations would still be susceptible to the sitafloxacin regimen. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Discrimination between Mycoplasma mycoides subsp. capri and Mycoplasma capricolum subsp. capricolum using PCR-RFLP and PCR.

    PubMed

    Cillara, Grazia; Manca, Maria Giovanna; Longheu, Carla; Tola, Sebastiana

    2015-09-01

    In this study, the dihydrolipoyl dehydrogenase (lpdA) gene was used to distinguish Mycoplasma mycoides subsp. capri (Mmc) from Mycoplasma capricolum subsp. capricolum (Mcc), two of four Mycoplasma species that cause contagious agalactia in sheep and goats. After alignment of nucleotide sequences of both species, specific primer sets were designed from unchanging and variable gene segments. The first primer set LPD-C1-F/LPD-C1-R was used to amplify a 911 bp fragment that was subsequently co-digested with FastDigest PstI, SspI, EcoRI and ClaI enzymes. The PCR-RFLP profiles differentiated the two mycoplasma species. The second primer set was used to distinguish Mmc from Mcc by single tube PCR. Both methods were further applied to identify 54 isolates collected from dairy herds from different provinces in Sardinia. The results of this study showed that PCR-RFLP and PCR could be used in routine diagnosis for rapid and specific simultaneous discrimination of Mmc and Mcc.

  5. What are mycoplasmas - The relationship of tempo and mode in bacterial evolution

    NASA Technical Reports Server (NTRS)

    Woese, C. R.; Stackebrand, E.; Ludwig, W.

    1985-01-01

    In phenotype the mycoplasmas are very different from ordinary bacteria. However, genotypically (i.e., phylogenetically) they are not. On the basis of ribosomal RNA homologies the mycoplasmas belong with the clostridia, and indeed have specific clostridial relatives. Mycoplasmas are, however, unlike almost all other bacteria in the evolutionary characteristics of their ribosomal RNAs. These RNAs contain relatively few of the highly conserved oligonucleotide sequences characteristic of normal eubacterial ribosomal RNAs. This is interpreted to be a reflection of an elevated mutation rate in mycoplasma lines of descent. A general consequence of this would be that the variation associated with a mycoplasma population is augmented both in number and kind, which in turn would lead to an unusual evolutionary course, one unique in all respects. Mycoplasmas, then, are actually tachytelic bacteria. The unusual evolutionary characteristics of their ribosomal RNAs are the imprints of their rapid evolution.

  6. What are mycoplasmas: the relationship of tempo and mode in bacterial evolution

    NASA Technical Reports Server (NTRS)

    Woese, C. R.; Stackebrandt, E.; Ludwig, W.

    1984-01-01

    In phenotype the mycoplasmas are very different from ordinary bacteria. However, genotypically (i.e., phylogenetically) they are not. On the basis of ribosomal RNA homologies the mycoplasmas belong with the clostridia, and indeed have specific clostridial relatives. Mycoplasmas are, however, unlike almost all other bacteria in the evolutionary characteristics of their ribosomal RNAs. These RNAs contain relatively few of the highly conserved oligonucleotide sequences characteristic of normal eubacterial ribosomal RNAs. This is interpreted to be a reflection of an elevated mutation rate in mycoplasma lines of descent. A general consequence of this would be that the variation associated with a mycoplasma population is augmented both in number and kind, which in turn would lead to an unusual evolutionary course, one unique in all respects. Mycoplasmas, then, are actually tachytelic bacteria. The unusual evolutionary characteristics of their ribosomal RNAs are the imprints of their rapid evolution.

  7. Novel hemotropic Mycoplasma species in white-tailed deer (Odocoileus virginianus).

    PubMed

    Maggi, Ricardo G; Chitwood, M Colter; Kennedy-Stoskopf, Suzanne; DePerno, Christopher S

    2013-12-01

    Globally, hemotropic Mycoplasma spp. are emerging or re-emerging zoonotic pathogens that affect livestock, wildlife, companion animals, and humans, potentially causing serious and economically important disease problems. Little is known about hemotropic Mycoplasma spp. prevalence, host-specificity, or route of transmission in most species, including wildlife. DNA amplification by PCR targeting the 16SrRNA and the RNaseP genes was used to establish the presence and prevalence of hemotropic Mycoplasma spp. in a white-tailed deer (O. virginianus) population in eastern North Carolina. Sixty-five deer (89%) tested positive for hemotropic Mycoplasma spp. where sequence analysis of the 16SsRNA and the RNaseP genes indicated the presence of at least three distinct species. This study represents the first detection of three distinct hemotropic Mycoplasma species in white-tailed deer and the first report of two novel hemotropic Mycoplasma species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Infection with hemotropic Mycoplasma species in patients with or without extensive arthropod or animal contact.

    PubMed

    Maggi, Ricardo G; Compton, Sarah M; Trull, Chelsea L; Mascarelli, Patricia E; Mozayeni, B Robert; Breitschwerdt, Edward B

    2013-10-01

    PCR amplification targeting the 16S rRNA gene was used to test individuals with and without extensive arthropod and animal contact for the possibility of hemotropic mycoplasma infection. The prevalence of hemotropic mycoplasma infection (4.7%) was significantly greater in previously reported cohorts of veterinarians, veterinary technicians, spouses of veterinary professionals, and others with extensive arthropod exposure and/or frequent animal contact than in a previously reported cohort of patients examined by a rheumatologist because of chronic joint pain or evidence of small-vessel disease (0.7%). Based upon DNA sequence analysis, a Mycoplasma ovis-like species was the most prevalent organism detected; however, infection with "Candidatus Mycoplasma haematoparvum" and a potentially novel, but incompletely characterized, hemotropic Mycoplasma species was also documented. Historical exposure to animals and arthropod vectors that can harbor hemotropic Mycoplasma spp. should be considered during epidemiological investigations and in the evaluation of individual patients.

  9. What are mycoplasmas: the relationship of tempo and mode in bacterial evolution.

    PubMed

    Woese, C R; Stackebrandt, E; Ludwig, W

    In phenotype the mycoplasmas are very different from ordinary bacteria. However, genotypically (i.e., phylogenetically) they are not. On the basis of ribosomal RNA homologies the mycoplasmas belong with the clostridia, and indeed have specific clostridial relatives. Mycoplasmas are, however, unlike almost all other bacteria in the evolutionary characteristics of their ribosomal RNAs. These RNAs contain relatively few of the highly conserved oligonucleotide sequences characteristic of normal eubacterial ribosomal RNAs. This is interpreted to be a reflection of an elevated mutation rate in mycoplasma lines of descent. A general consequence of this would be that the variation associated with a mycoplasma population is augmented both in number and kind, which in turn would lead to an unusual evolutionary course, one unique in all respects. Mycoplasmas, then, are actually tachytelic bacteria. The unusual evolutionary characteristics of their ribosomal RNAs are the imprints of their rapid evolution.

  10. What are mycoplasmas - The relationship of tempo and mode in bacterial evolution

    NASA Technical Reports Server (NTRS)

    Woese, C. R.; Stackebrand, E.; Ludwig, W.

    1985-01-01

    In phenotype the mycoplasmas are very different from ordinary bacteria. However, genotypically (i.e., phylogenetically) they are not. On the basis of ribosomal RNA homologies the mycoplasmas belong with the clostridia, and indeed have specific clostridial relatives. Mycoplasmas are, however, unlike almost all other bacteria in the evolutionary characteristics of their ribosomal RNAs. These RNAs contain relatively few of the highly conserved oligonucleotide sequences characteristic of normal eubacterial ribosomal RNAs. This is interpreted to be a reflection of an elevated mutation rate in mycoplasma lines of descent. A general consequence of this would be that the variation associated with a mycoplasma population is augmented both in number and kind, which in turn would lead to an unusual evolutionary course, one unique in all respects. Mycoplasmas, then, are actually tachytelic bacteria. The unusual evolutionary characteristics of their ribosomal RNAs are the imprints of their rapid evolution.

  11. Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves

    PubMed Central

    Klomp, D. A.; Stuart-Fox, D.; Das, I.; Ord, T. J.

    2014-01-01

    Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds. PMID:25540157

  12. Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves.

    PubMed

    Klomp, D A; Stuart-Fox, D; Das, I; Ord, T J

    2014-12-01

    Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Identification and purification of arginine deiminase that originated from Mycoplasma arginini.

    PubMed Central

    Sugimura, K; Fukuda, S; Wada, Y; Taniai, M; Suzuki, M; Kimura, T; Ohno, T; Yamamoto, K; Azuma, I

    1990-01-01

    A lymphocyte blastogenesis inhibitory factor, (LBIF), was purified from the culture supernatant of human histiocytic lymphoma U937 by fast protein liquid chromatography. In this study, we demonstrated, first, that LBIF originated from a mycoplasma, Mycoplasma arginini, infecting U937 cells, and second, that LBIF bore the arginine deiminase activity. The implication of in vivo immunosuppression induced by arginine-utilizing mycoplasma species is discussed. Images PMID:2370103

  14. The History of Mycoplasma pneumoniae Pneumonia

    PubMed Central

    Saraya, Takeshi

    2016-01-01

    Pinehurst transmission experiments resulted in a lapse of 20 years before acceptance of the Eaton agent as Mycoplasma pneumoniae. This review describes the history of M. pneumoniae pneumonia with a special focus on the recognition between the 1930 and 1960s of the Eaton agent as the infectious cause. PMID:27047477

  15. In Vitro Antibacterial Activity of AZD0914 against Human Mycoplasmas and Ureaplasmas

    PubMed Central

    Crabb, Donna M.; Duffy, Lynn B.; Huband, Michael D.

    2015-01-01

    In this study, susceptibilities were determined for AZD0914, a spiropyrimidinetrione DNA gyrase inhibitor, azithromycin, doxycycline, and levofloxacin against Mycoplasma and Ureaplasma species. The activity of AZD0914 was comparable to that of levofloxacin and doxycycline against Mycoplasma genitalium and Mycoplasma pneumoniae. The AZD0914 MIC90 against Mycoplasma hominis was 8-fold greater than that for levofloxacin. The AZD0914 MIC90 against Ureaplasma species was 4-fold less than that for azithromycin and 8-fold less than that for levofloxacin and doxycycline. PMID:25824220

  16. Mycoplasma detection and isolation from one-humped camels (Camelus dromedarius).

    PubMed

    Mederos-Iriarte, Lidia E; Poveda, José B; Poveda, Carlos G; Vega-Orellana, Orestes M; Gutiérrez, Carlos; Corbera, Juan A; Ramírez, Ana S

    2014-10-01

    In scientific literature, a small amount of information is found concerning mycoplasmosis in camel species. Mycoplasma (M.) arginini, Acholeplasma (A.) laidlawii, and Acholeplasma oculi have been reported to be isolated from these host species. Serologically positive results have been reported for Mycoplasma mycoides subsp. mycoides SC type, Mycoplasma capricolum subsp. capripneumoniae, and M. mycoides subsp. capri. The aims of this study were to detect, isolate, and identify mycoplasmas from camels (Camelus dromedarius). Initially, saliva and ear smears plus conjunctival and vaginal secretions were taken from five female animals, but only conjunctival secretions in three male animals, all belonging to the same farm. An unknown mycoplasma was isolated from one of the vagina samples. Additionally, another unknown and uncultured mycoplasma was detected with molecular biology in the same sample. In the second stage, 23 vaginal secretions were taken from the same farm plus another secretion from a different one. Ten isolates of the same unknown and previously isolated mycoplasma were detected, nine of them recovered from the vagina of female camels. Some mycoplasmas have been related to reproductive disorders; however, there is no evidence that the isolated mycoplasmas are related to such disorders.

  17. Comparison of the prevalence of Mycoplasma species in dogs with and without respiratory disease.

    PubMed

    Schulz, Bianka S; Raufeisen, Katharina; Weber, Karin; Laberke, Siija; Hartmann, Katrin

    2015-01-01

    Aim of the study was to investigate the prevalence of Mycoplasma species in dogs with and without signs of respiratory disease. Bronchoalveolarlavage fluid (BALF) and pharyngeal swabs were collected from 29 dogs with respiratory diseases (RD) and 16 dogs without signs of RD that were euthanised because of other diseases. Samples were tested for Mycoplasma species by PCR and culture, and sequencing was performed in Mycoplasma species-positive BALF samples. Pharyngeal swabs were positive for Mycoplasma species by PCR in 91.7% of dogs with RD and 86.7% of dogs without signs of RD (p = 1.000); BALF samples were PCR-positive in 37.9% of dogs with RD and 18.8% of dogs without signs of RD (p = 0.194) Mycoplasmo culture of BALF was positive in 28.6% of dogs with RD and in 18.8% without signs of RD (p = 0.730). When culture and PCR were compared, there was no significant difference in the detection rate of Mycoplasma species (p = 0.658) Sequencing detected different Mycoplasma species. Out of these, however, Mycoplasma cynos was isolated from four dogs with RD. There is no significant difference in the prevalence of Mycoplasma species between dogs with RD and dogs without evidence of RD; however, Mycoplasma cynos seems to be associated with respiratory disease.

  18. Detection and Antibiotic Treatment of Mycoplasma arginini Contamination in a Mouse Epithelial Cell Line Restore Normal Cell Physiology

    PubMed Central

    Resnick, Andrew

    2014-01-01

    Mycoplasma contamination of cultured cell lines is difficult to detect by routine observation. Infected cells can display normal morphology and the slow growth rate of mycoplasma can delay detection for extended periods of time, compromising experimental results. Positive identification of mycoplasma typically requires cells to be either fixed and stained for DNA or processed with PCR. We present a method to detect mycoplasma using live-cell optical microscopy typically used for routine observation of cell cultures. Images of untreated mycoplasma-infected epithelial cells alongside images of infected cells treated with Plasmocin, a commercially available antibiotic targeted to mycoplasma, are shown. We found that optical imaging is an effective screening tool for detection of mycoplasma contamination. Importantly, we found that cells regained normal function after the contamination was cleared. In conclusion, we present a technique to diagnose probable mycoplasma infections in live cultures without fixation, resulting in faster response times and decreased loss of cell material. PMID:24772428

  19. Generation of a monoclonal antibody against Mycoplasma spp. following accidental contamination during production of a monoclonal antibody against Lawsonia intracellularis.

    PubMed

    Hwang, Jeong-Min; Lee, Ji-Hye; Yeh, Jung-Yong

    2012-03-01

    This report describes Mycoplasma contamination of Lawsonia intracellularis cultures that led to the unintended acquisition of a monoclonal antibody against Mycoplasma spp. during the attempted generation of a monoclonal antibody against L. intracellularis.

  20. Detection and antibiotic treatment of Mycoplasma arginini contamination in a mouse epithelial cell line restore normal cell physiology.

    PubMed

    Boslett, Brianna; Nag, Subhra; Resnick, Andrew

    2014-01-01

    Mycoplasma contamination of cultured cell lines is difficult to detect by routine observation. Infected cells can display normal morphology and the slow growth rate of mycoplasma can delay detection for extended periods of time, compromising experimental results. Positive identification of mycoplasma typically requires cells to be either fixed and stained for DNA or processed with PCR. We present a method to detect mycoplasma using live-cell optical microscopy typically used for routine observation of cell cultures. Images of untreated mycoplasma-infected epithelial cells alongside images of infected cells treated with Plasmocin, a commercially available antibiotic targeted to mycoplasma, are shown. We found that optical imaging is an effective screening tool for detection of mycoplasma contamination. Importantly, we found that cells regained normal function after the contamination was cleared. In conclusion, we present a technique to diagnose probable mycoplasma infections in live cultures without fixation, resulting in faster response times and decreased loss of cell material.

  1. Functional gliding spaces of the dorsal side of the human finger.

    PubMed

    Schubert, M; Bade, H; Notermans, H P; Knifka, J; Koebke, J

    1996-01-01

    Although the clinical and functional importance of gliding and connective tissue spaces has been repeatedly emphasized (e.g. their role in the spreading of suppurative phlegmonic inflammation) only few literary findings can be presented dealing with the connective tissue spaces in the finger in the metacarpo-phalangeal transition region. Three separate gliding spaces of the finger above the dorsal aponeurosis and their various regional connections can be displayed by means of a plastic injection technique followed by plastination and production of sectional series. These gliding spaces were also examined on fixed and unfixed hands using plastic injection and subsequent dissection. A space was depicted between the proximal interphalangeal joint and the insertion of the dorsal aponeurosis on the distal phalanx of the finger, as well as a further bursa-like space over the proximal interphalangeal joint. A third space was also depicted between the metacarpophalangeal joint and the proximal interphalangeal joint, which displays a variable connection to the gliding canal of the respective extensor tendons. Methodical, functional and clinical aspects will be discussed.

  2. The Hydrodynamic Study of the Swimming Gliding: a Two-Dimensional Computational Fluid Dynamics (CFD) Analysis.

    PubMed

    Marinho, Daniel A; Barbosa, Tiago M; Rouboa, Abel I; Silva, António J

    2011-09-01

    Nowadays the underwater gliding after the starts and the turns plays a major role in the overall swimming performance. Hence, minimizing hydrodynamic drag during the underwater phases should be a main aim during swimming. Indeed, there are several postures that swimmers can assume during the underwater gliding, although experimental results were not conclusive concerning the best body position to accomplish this aim. Therefore, the purpose of this study was to analyse the effect in hydrodynamic drag forces of using different body positions during gliding through computational fluid dynamics (CFD) methodology. For this purpose, two-dimensional models of the human body in steady flow conditions were studied. Two-dimensional virtual models had been created: (i) a prone position with the arms extended at the front of the body; (ii) a prone position with the arms placed alongside the trunk; (iii) a lateral position with the arms extended at the front and; (iv) a dorsal position with the arms extended at the front. The drag forces were computed between speeds of 1.6 m/s and 2 m/s in a two-dimensional Fluent(®) analysis. The positions with the arms extended at the front presented lower drag values than the position with the arms aside the trunk. The lateral position was the one in which the drag was lower and seems to be the one that should be adopted during the gliding after starts and turns.

  3. Remote Photoregulated Ring Gliding in a [2]Rotaxane via a Molecular Effector.

    PubMed

    Tron, Arnaud; Pianet, Isabelle; Martinez-Cuezva, Alberto; Tucker, James H R; Pisciottani, Luca; Alajarin, Mateo; Berna, Jose; McClenaghan, Nathan D

    2017-01-06

    A molecular barbiturate messenger, which is reversibly released/captured by a photoswitchable artificial molecular receptor, is shown to act as an effector to control ring gliding on a distant hydrogen-bonding [2]rotaxane. Thus, light-driven chemical communication governing the operation of a remote molecular machine is demonstrated using an information-rich neutral molecule.

  4. The effects of real and illusory glides on pure-tone frequency discrimination

    NASA Astrophysics Data System (ADS)

    Lyzenga, J.; Carlyon, R. P.; Moore, B. C. J.

    2004-07-01

    Experiment 1 measured pure-tone frequency difference limens (DLs) at 1 and 4 kHz. The stimuli had two steady-state portions, which differed in frequency for the target. These portions were separated by a middle section of varying length, which consisted of a silent gap, a frequency glide, or a noise burst (conditions: gap, glide, and noise, respectively). The noise burst created an illusion of the tone continuing through the gap. In the first condition, the stimuli had an overall duration of 500 ms. In the second condition, stimuli had a fixed 50-ms middle section, and the overall duration was varied. DLs were lower for the glide than for the gap condition, consistent with the idea that the auditory system contains a mechanism specific for the detection of dynamic changes. DLs were generally lower for the noise than for the gap condition, suggesting that this mechanism extracts information from an illusory glide. In a second experiment, pure-tone frequency direction-discrimination thresholds were measured using similar stimuli as for the first experiment. For this task, the type of the middle section hardly affected the thresholds, suggesting that the frequency-change detection mechanism does not facilitate the identification of the direction of frequency changes.

  5. Flavobacterium columnare type IX secretion system mutations result in defects in gliding motility and virulence

    USDA-ARS?s Scientific Manuscript database

    Background: The gliding bacterium Flavobacterium columnare causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. The related bacterium Flavobacterium johnsoniae uses a type IX secretion system (T9SS) to secrete enzy...

  6. Evolutionarily divergent, unstable filamentous actin is essential for gliding motility in apicomplexan parasites.

    PubMed

    Skillman, Kristen M; Diraviyam, Karthikeyan; Khan, Asis; Tang, Keliang; Sept, David; Sibley, L David

    2011-10-01

    Apicomplexan parasites rely on a novel form of actin-based motility called gliding, which depends on parasite actin polymerization, to migrate through their hosts and invade cells. However, parasite actins are divergent both in sequence and function and only form short, unstable filaments in contrast to the stability of conventional actin filaments. The molecular basis for parasite actin filament instability and its relationship to gliding motility remain unresolved. We demonstrate that recombinant Toxoplasma (TgACTI) and Plasmodium (PfACTI and PfACTII) actins polymerized into very short filaments in vitro but were induced to form long, stable filaments by addition of equimolar levels of phalloidin. Parasite actins contain a conserved phalloidin-binding site as determined by molecular modeling and computational docking, yet vary in several residues that are predicted to impact filament stability. In particular, two residues were identified that form intermolecular contacts between different protomers in conventional actin filaments and these residues showed non-conservative differences in apicomplexan parasites. Substitution of divergent residues found in TgACTI with those from mammalian actin resulted in formation of longer, more stable filaments in vitro. Expression of these stabilized actins in T. gondii increased sensitivity to the actin-stabilizing compound jasplakinolide and disrupted normal gliding motility in the absence of treatment. These results identify the molecular basis for short, dynamic filaments in apicomplexan parasites and demonstrate that inherent instability of parasite actin filaments is a critical adaptation for gliding motility.

  7. An In Vitro Comparison of Root Canal Transportation by Reciproc File With and Without Glide Path

    PubMed Central

    Nazarimoghadam, Kiumars; Daryaeian, Mohammad; Ramazani, Nahid

    2014-01-01

    Objective: The aim of ideal canal preparation is to prevent iatrogenic aberrations such as transportation. The aim of this study was to evaluate the root canal transportation by Reciproc file with and without glide path. Materials and Methods: Thirty acrylic-resin blocks with a curvature of 60° and size#10 (2% taper) were assigned into two groups (n= 15). In group 1, the glide path was performed using stainless steel k-files size#10 and 15 at working length In group 2, canals were prepared with Reciproc file system at working length. By using digital imaging software (AutoCAD 2008), the pre-instrumentation and post-instrumentation digital images were superimposed over, taking the landmarks as reference points. Then the radius of the internal and external curve of the specimens was calculated at three α, β and γ points (1mm to apex as α, 3mm to apex as β, and 5mm to apex as γ). The data were statically analyzed using the independent T-test and Mann-Whitney U test by SPSS version 16. Results: Glide path was found significant for only external curve in the apical third of the canal; that is, 5mm to apex (P=0.005). But in the other third, canal modification was not significant (P> 0.008). Conclusion: Canal transportation in the apical third of the canal seems to be significantly reduced when glide path is performed using reciprocating files. PMID:25628682

  8. The Hydrodynamic Study of the Swimming Gliding: a Two-Dimensional Computational Fluid Dynamics (CFD) Analysis

    PubMed Central

    Marinho, Daniel A.; Barbosa, Tiago M.; Rouboa, Abel I.; Silva, António J.

    2011-01-01

    Nowadays the underwater gliding after the starts and the turns plays a major role in the overall swimming performance. Hence, minimizing hydrodynamic drag during the underwater phases should be a main aim during swimming. Indeed, there are several postures that swimmers can assume during the underwater gliding, although experimental results were not conclusive concerning the best body position to accomplish this aim. Therefore, the purpose of this study was to analyse the effect in hydrodynamic drag forces of using different body positions during gliding through computational fluid dynamics (CFD) methodology. For this purpose, two-dimensional models of the human body in steady flow conditions were studied. Two-dimensional virtual models had been created: (i) a prone position with the arms extended at the front of the body; (ii) a prone position with the arms placed alongside the trunk; (iii) a lateral position with the arms extended at the front and; (iv) a dorsal position with the arms extended at the front. The drag forces were computed between speeds of 1.6 m/s and 2 m/s in a two-dimensional Fluent® analysis. The positions with the arms extended at the front presented lower drag values than the position with the arms aside the trunk. The lateral position was the one in which the drag was lower and seems to be the one that should be adopted during the gliding after starts and turns. PMID:23486656

  9. Carborane Clusters in Computational Drug Design: A Comparative Docking Evaluation Using Autodock, Flexx, Glide and Surflex#

    PubMed Central

    Tiwari, Rohit; Mahasenan, Kiran; Pavlovicz, Ryan; Li, Chenglong; Tjarks, Werner

    2009-01-01

    Compounds containing boron atoms play increasingly important roles in the therapy and diagnosis of various diseases, particularly cancer. However, computational drug design of boron-containing therapeutics and diagnostics is hampered by the fact that many software packages used for this purpose lack parameters for all or part of the various types of boron atoms. In the present paper, we describe simple and efficient strategies to overcome this problem, which are based on the replacement of the boron atom types with carbon atom types. The developed methods were validated by docking closo- and nido-carboranyl antifolates into the active site of a human dihydrofolate reductase (hDHFR) using AutoDock, Glide, FlexX, and Surflex and comparing the obtained docking poses with the poses of their counterparts in the original hDHFR-carboranyl antifolate crystal structures. Under optimized conditions, AutoDock and Glide were equally good in docking of the closo-carboranyl antifolates followed by Surflex and FlexX whereas Autodock, Glide, and Surflex proved to be comparably efficient in the docking of nido-carboranyl antifolates followed by FlexX. Differences in geometries and partial atom charges in the structures of the carboranyl antifolates resulting from different data sources and/or optimization methods did not impact the docking performances of AutoDock or Glide significantly. Scoring functions generated by all four programs were in accordance with experimental data. PMID:19449853

  10. STS-26 Discovery, OV-103, with landing gear deployed glides above EAFB runway

    NASA Image and Video Library

    1988-10-03

    STS-26 Discovery, Orbiter Vehicle (OV) 103, with nose landing gear (NLG) and main landing gear (MLG) deployed glides above dry lakebed runway 17 at Edwards Air Force Base (EAFB), California. This profile view shows OV-103's port side just before MLG touchdown.

  11. The effect of lubricin on the gliding resistance of mouse intrasynovial tendon.

    PubMed

    Hayashi, Masanori; Zhao, Chunfeng; Thoreson, Andrew R; Chikenji, Takako; Jay, Gregory D; An, Kai-Nan; Amadio, Peter C

    2013-01-01

    The purpose of this study was to investigate the role of lubricin on the gliding resistance of intrasynovial tendons by comparing lubricin knockout, heterozygous, and wild type mice. A total of thirty-six deep digital flexor (DDF) tendons in the third digits of each hind paw from eighteen adult mice were used, including six lubricin knockout mice (Prg4 -/-), six heterozygous mice (Prg4 +/-), and six wild type mice (Prg4 +/+). The tendon gliding resistance was measured using a custom-made device. Tendon structural changes were evaluated by scanning electron and light microscopy. The gliding resistance of intrasynovial tendons from lubricin knockout mice was significantly higher than the gliding resistance of either wild type or heterozygous mice. The surface of the lubricin knockout tendons appeared to be rougher, compared to the wild type and heterozygous tendons. Synovial hyperplasia was found in the lubricin knockout mice. Cartilage-like tissue was found in the tendon and pulley of the lubricin knockout mice. Our findings confirm the importance of lubricin in intrasynovial tendon lubrication. This knockout model may be useful in determining the effect of lubricin on tendon healing and the response to injury.

  12. 14 CFR 121.360 - Ground proximity warning-glide slope deviation alerting system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ground proximity warning-glide slope deviation alerting system. 121.360 Section 121.360 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS:...

  13. Use of glide-ins in CMS for production and analysis

    SciTech Connect

    Bradley, D.; Gutsche, O.; Hahn, K.; Holzman, B.; Padhi, S.; Pi, H.; Spiga, D.; Sfiligoi, I.; Vaandering, E.; Wurthwein, F.; /UC, San Diego

    2010-01-01

    With the evolution of various grid federations, the Condor glide-ins represent a key feature in providing a homogeneous pool of resources using late-binding technology. The CMS collaboration uses the glide-in based Workload Management System, glideinWMS, for production (ProdAgent) and distributed analysis (CRAB) of the data. The Condor glide-in daemons traverse to the worker nodes, submitted via Condor-G. Once activated, they preserve the Master-Worker relationships, with the worker first validating the execution environment on the worker node before pulling the jobs sequentially until the expiry of their lifetimes. The combination of late-binding and validation significantly reduces the overall failure rate visible to CMS physicists. We discuss the extensive use of the glideinWMS since the computing challenge, CCRC-08, in order to prepare for the forthcoming LHC data-taking period. The key features essential to the success of large-scale production and analysis on CMS resources across major grid federations, including EGEE, OSG and NorduGrid are outlined. Use of glide-ins via the CRAB server mechanism and ProdAgent, as well as first hand experience of using the next generation CREAM computing element within the CMS framework is discussed.

  14. Use of glide-ins in CMS for production and analysis

    NASA Astrophysics Data System (ADS)

    Bradley, D.; Gutsche, O.; Hahn, K.; Holzman, B.; Padhi, S.; Pi, H.; Spiga, D.; Sfiligoi, I.; Vaandering, E.; Würthwein, F.; CMS Offline Computing Projects

    2010-04-01

    With the evolution of various grid federations, the Condor glide-ins represent a key feature in providing a homogeneous pool of resources using late-binding technology. The CMS collaboration uses the glide-in based Workload Management System, glideinWMS, for production (ProdAgent) and distributed analysis (CRAB) of the data. The Condor glide-in daemons traverse to the worker nodes, submitted via Condor-G. Once activated, they preserve the Master-Worker relationships, with the worker first validating the execution environment on the worker node before pulling the jobs sequentially until the expiry of their lifetimes. The combination of late-binding and validation significantly reduces the overall failure rate visible to CMS physicists. We discuss the extensive use of the glideinWMS since the computing challenge, CCRC-08, in order to prepare for the forthcoming LHC data-taking period. The key features essential to the success of large-scale production and analysis on CMS resources across major grid federations, including EGEE, OSG and NorduGrid are outlined. Use of glide-ins via the CRAB server mechanism and ProdAgent, as well as first hand experience of using the next generation CREAM computing element within the CMS framework is discussed.

  15. Evolutionarily Divergent, Unstable Filamentous Actin Is Essential for Gliding Motility in Apicomplexan Parasites

    PubMed Central

    Skillman, Kristen M.; Diraviyam, Karthikeyan; Khan, Asis; Tang, Keliang; Sept, David; Sibley, L. David

    2011-01-01

    Apicomplexan parasites rely on a novel form of actin-based motility called gliding, which depends on parasite actin polymerization, to migrate through their hosts and invade cells. However, parasite actins are divergent both in sequence and function and only form short, unstable filaments in contrast to the stability of conventional actin filaments. The molecular basis for parasite actin filament instability and its relationship to gliding motility remain unresolved. We demonstrate that recombinant Toxoplasma (TgACTI) and Plasmodium (PfACTI and PfACTII) actins polymerized into very short filaments in vitro but were induced to form long, stable filaments by addition of equimolar levels of phalloidin. Parasite actins contain a conserved phalloidin-binding site as determined by molecular modeling and computational docking, yet vary in several residues that are predicted to impact filament stability. In particular, two residues were identified that form intermolecular contacts between different protomers in conventional actin filaments and these residues showed non-conservative differences in apicomplexan parasites. Substitution of divergent residues found in TgACTI with those from mammalian actin resulted in formation of longer, more stable filaments in vitro. Expression of these stabilized actins in T. gondii increased sensitivity to the actin-stabilizing compound jasplakinolide and disrupted normal gliding motility in the absence of treatment. These results identify the molecular basis for short, dynamic filaments in apicomplexan parasites and demonstrate that inherent instability of parasite actin filaments is a critical adaptation for gliding motility. PMID:21998582

  16. The double sheath system and tendon gliding in zone 2C.

    PubMed

    Tang, J B

    1995-06-01

    Anatomical structures, the morphology of gliding tunnel, the gliding amplitude of tendons and the range of finger motion after sheath incision in zone 2C were studied in 40 fingers of ten preserved cadaver hands. The tendon of FDS in zone 2C courses around that of FDP, and FDS serves functionally as a second sheath for FDP. This "double sheath" system in zone 2C accounts for the poor results of tendon repair in zone 2C. The tendon repairs in zone 2C glide into zone 2D during finger flexion. Therefore, the condition of the gliding tunnel of zone 2D is also important to the function of tendon repairs in zone 2C. The range of motion was shown to be insignificantly influenced by partial incision of the A2 pulley, and this did not decrease the total strength of the sheath markedly. These suggest that partial incision or enlargement of the A2 pulley can be carried out for tendon repairs in zone 2C without causing mechanical problems of function.

  17. Temporal evolution characteristics of an annular-mode gliding arc discharge in a vortex flow

    SciTech Connect

    Zhao, Tian-Liang; Liu, Jing-Lin; Li, Xiao-Song; Liu, Jin-Bao; Song, Yuan-Hong; Xu, Yong; Zhu, Ai-Min

    2014-05-15

    An annular-mode gliding arc discharge powered by a 50 Hz alternating current (ac) supply was studied in a vortex flow of dry and humid air. Its temporal evolution characteristics were investigated by electrical measurement, temporally resolved imaging, and temporally resolved optical emission spectroscopic measurements. Three discharge stages of arc-ignition, arc-gliding, and arc-extinction were clearly observed in each half-cycle of the discharge. During the arc-gliding stage, the intensity of light emission from the arc root at the cathode was remarkably higher than that at other areas. The spectral intensity of N{sub 2}(C{sup 3}Π{sub u}−B{sup 3}Π{sub g}) during the arc-ignition stage was much higher than that during the arc-gliding stage, which was contrary to the temporal evolutions of spectral intensities for N{sub 2}{sup +}(B{sup 2}Σ{sub u}{sup +}−X{sup 2}Σ{sub g}{sup +}) and OH(A{sup 2}Σ{sup +}−X{sup 2}Π{sub i}). Temporally resolved vibrational and rotational temperatures of N{sub 2} were also presented and decreased with increasing the water vapor content.

  18. Effect of pH on Human Mycoplasma Strains

    PubMed Central

    Shepard, Maurice C.; Lunceford, Carl D.

    1965-01-01

    Shepard, Maurice C. (U.S. Naval Medical Field Research Laboratory, Camp Lejeune, N.C.), and Carl D. Lunceford. Effect of pH on human Mycoplasma strains. J. Bacteriol. 89:265–270. 1965.—The optimal reaction of culture media for the cultivation of T-strain Mycoplasma of human origin was investigated. By use of a recently modified tryptic digest medium, the optimal reaction in either agar or fluid medium was found to be pH 6.0. In contrast, human classic (large-colony) Mycoplasma could be cultivated in agar or fluid medium over a rather broad pH range, and the influence of the reaction of the medium appeared to be primarily species-dependent. M. salivarium, for example, grew best in agar from pH 5.5 through 6.5. M. pneumoniae (Easton's agent) yielded largest colony numbers in agar and highest titers in broth at pH 8.0. In the case of T-strain Mycoplasma, both maximal colony numbers in agar and highest titers in fluid media were achieved at a reaction of pH 6.0. In addition, largest colony size of T-strain Mycoplasma was also achieved in agar at pH 6.0, and averaged 50 to 100% larger than that obtained by cultivation at pH 8.0 with the same medium. Although T-strains will develop in agar media over a pH range of from 5.0 through 10.0, the extremely small colony size and poor staining properties resulting from growth in an alkaline medium make their recognition in agar cultures difficult. Aerobic cultivation of T-strains was first achieved in agar adjusted to pH 5.5 to 6.0. In fluid medium, multiplication of T-strains occurred only within the limits of pH 5.0 through 8.0, with highest titers being reached at pH 6.0. Greater attention to the reaction of complete Mycoplasma media is stressed. PMID:14255688

  19. Involvement of the Type IX Secretion System in Capnocytophaga ochracea Gliding Motility and Biofilm Formation

    PubMed Central

    Kita, Daichi; Shibata, Satoshi; Kikuchi, Yuichiro; Kokubu, Eitoyo; Nakayama, Koji; Saito, Atsushi

    2016-01-01

    Capnocytophaga ochracea is a Gram-negative, rod-shaped bacterium that demonstrates gliding motility when cultured on solid agar surfaces. C. ochracea possesses the ability to form biofilms; however, factors involved in biofilm formation by this bacterium are unclear. A type IX secretion system (T9SS) in Flavobacterium johnsoniae was shown to be involved in the transport of proteins (e.g., several adhesins) to the cell surface. Genes orthologous to those encoding T9SS proteins in F. johnsoniae have been identified in the genome of C. ochracea; therefore, the T9SS may be involved in biofilm formation by C. ochracea. Here we constructed three ortholog-deficient C. ochracea mutants lacking sprB (which encodes a gliding motility adhesin) or gldK or sprT (which encode T9SS proteins in F. johnsoniae). Gliding motility was lost in each mutant, suggesting that, in C. ochracea, the proteins encoded by sprB, gldK, and sprT are necessary for gliding motility, and SprB is transported to the cell surface by the T9SS. For the ΔgldK, ΔsprT, and ΔsprB strains, the amounts of crystal violet-associated biofilm, relative to wild-type values, were 49%, 34%, and 65%, respectively, at 48 h. Confocal laser scanning and scanning electron microscopy revealed that the biofilms formed by wild-type C. ochracea were denser and bacterial cells were closer together than in those formed by the mutant strains. Together, these results indicate that proteins exported by the T9SS are key elements of the gliding motility and biofilm formation of C. ochracea. PMID:26729712

  20. Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling.

    PubMed

    Wang, Weizong; Patil, Bhaskar; Heijkers, Stjin; Hessel, Volker; Bogaerts, Annemie

    2017-03-08

    The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO2 yields and the corresponding energy efficiency for NOx formation for different N2 /O2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NOx . The results indicate that vibrational excitation of N2 in the gliding arc contributes significantly to activating the N2 molecules, and leads to an energy efficient way of NOx production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NOx formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber-Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which low-temperature plasma technology might play an important role.

  1. Flexor digitorum superficialis repair outside the A2 pulley after zone II laceration: gliding and bowstringing.

    PubMed

    Geary, Michael B; English, Christopher; Yaseen, Zaneb; Stanbury, Spencer; Awad, Hani; Elfar, John C

    2015-04-01

    To evaluate the changes in maximum flexion angle, gliding coefficient, and bowstringing after a combined repair of both flexor tendons with the flexor digitorum superficialis (FDS) rerouted outside the A2 pulley in cadaveric hands. We performed 4 different repairs on cadaveric hands, with each repair tested on 9 unique digits. In total, 12 cadaveric hands and 36 digits were used. The thumb and little finger were removed from each hand and excluded from testing. Group 1 was sham surgery. Group 2 combined flexor digitorum profundus (FDP) and FDS laceration and repair with both slips of the FDS repaired inside the A2 pulley. Group 3 was FDP repair with one slip of the FDS repaired inside A2 and the other slip left unrepaired. Group 4 was FDP repair with both slips of the FDS rerouted and repaired outside the A2 pulley. Maximum flexion angle, gliding coefficient, and bowstringing were measured in simulated active digital motion for each group. Rerouting and repairing the FDS outside the A2 pulley (group 4) significantly lowered gliding coefficient compared with repairs with both slips inside A2, with values similar to sham surgery. We observed no significant differences in maximum flexion angle among the 4 groups. Increased bowstringing was observed with both slips of the FDS repaired and rerouted outside the A2 pulley. In this cadaveric model, repair of both slips of the FDS outside the A2 pulley improved the gliding coefficient relative to repair within the A2 pulley, which suggests decreased resistance to finger flexion. Repair of the FDS outside the A2 pulley led to a slight increase in bowstringing of the FDS tendon. We describe a technique for managing combined laceration of the FDP and FDS tendons that improves gliding function and merits consideration. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  2. The Effect of Depth on Drag During the Streamlined Glide: A Three-Dimensional CFD Analysis

    PubMed Central

    Novais, Maria L.; Silva, António J.; Mantha, Vishveshwar R.; Ramos, Rui J.; Rouboa, Abel I.; Vilas-Boas, J. Paulo; Luís, Sérgio R.; Marinho, Daniel A.

    2012-01-01

    The aim of this study was to analyze the effects of depth on drag during the streamlined glide in swimming using Computational Fluid Dynamics. The Computation Fluid Dynamic analysis consisted of using a three-dimensional mesh of cells that simulates the flow around the considered domain. We used the K-epsilon turbulent model implemented in the commercial code Fluent® and applied it to the flow around a three-dimensional model of an Olympic swimmer. The swimmer was modeled as if he were gliding underwater in a streamlined prone position, with hands overlapping, head between the extended arms, feet together and plantar flexed. Steady-state computational fluid dynamics analyses were performed using the Fluent® code and the drag coefficient and the drag force was calculated for velocities ranging from 1.5 to 2.5 m/s, in increments of 0.50m/s, which represents the velocity range used by club to elite level swimmers during the push-off and glide following a turn. The swimmer model middle line was placed at different water depths between 0 and 1.0 m underwater, in 0.25m increments. Hydrodynamic drag decreased with depth, although after 0.75m values remained almost constant. Water depth seems to have a positive effect on reducing hydrodynamic drag during the gliding. Although increasing depth position could contribute to decrease hydrodynamic drag, this reduction seems to be lower with depth, especially after 0.75 m depth, thus suggesting that possibly performing the underwater gliding more than 0.75 m depth could not be to the benefit of the swimmer. PMID:23487502

  3. The Effect of Depth on Drag During the Streamlined Glide: A Three-Dimensional CFD Analysis.

    PubMed

    Novais, Maria L; Silva, António J; Mantha, Vishveshwar R; Ramos, Rui J; Rouboa, Abel I; Vilas-Boas, J Paulo; Luís, Sérgio R; Marinho, Daniel A

    2012-06-01

    The aim of this study was to analyze the effects of depth on drag during the streamlined glide in swimming using Computational Fluid Dynamics. The Computation Fluid Dynamic analysis consisted of using a three-dimensional mesh of cells that simulates the flow around the considered domain. We used the K-epsilon turbulent model implemented in the commercial code Fluent(®) and applied it to the flow around a three-dimensional model of an Olympic swimmer. The swimmer was modeled as if he were gliding underwater in a streamlined prone position, with hands overlapping, head between the extended arms, feet together and plantar flexed. Steady-state computational fluid dynamics analyses were performed using the Fluent(®) code and the drag coefficient and the drag force was calculated for velocities ranging from 1.5 to 2.5 m/s, in increments of 0.50m/s, which represents the velocity range used by club to elite level swimmers during the push-off and glide following a turn. The swimmer model middle line was placed at different water depths between 0 and 1.0 m underwater, in 0.25m increments. Hydrodynamic drag decreased with depth, although after 0.75m values remained almost constant. Water depth seems to have a positive effect on reducing hydrodynamic drag during the gliding. Although increasing depth position could contribute to decrease hydrodynamic drag, this reduction seems to be lower with depth, especially after 0.75 m depth, thus suggesting that possibly performing the underwater gliding more than 0.75 m depth could not be to the benefit of the swimmer.

  4. Ancient phylogenetic divergence of the enigmatic African rodent Zenkerella and the origin of anomalurid gliding

    PubMed Central

    Fernández, David; Sallam, Hesham M.; Cronin, Drew T.; Esara Echube, José Manuel

    2016-01-01

    The “scaly-tailed squirrels” of the rodent family Anomaluridae have a long evolutionary history in Africa, and are now represented by two gliding genera (Anomalurus and Idiurus) and a rare and obscure genus (Zenkerella) that has never been observed alive by mammalogists. Zenkerella shows no anatomical adaptations for gliding, but has traditionally been grouped with the glider Idiurus on the basis of craniodental similarities, implying that either the Zenkerella lineage lost its gliding adaptations, or that Anomalurus and Idiurus evolved theirs independently. Here we present the first nuclear and mitochondrial DNA sequences of Zenkerella, based on recently recovered whole-body specimens from Bioko Island (Equatorial Guinea), which show unambiguously that Zenkerella is the sister taxon of Anomalurus and Idiurus. These data indicate that gliding likely evolved only once within Anomaluridae, and that there were no subsequent evolutionary reversals. We combine this new molecular evidence with morphological data from living and extinct anomaluromorph rodents and estimate that the lineage leading to Zenkerella has been evolving independently in Africa since the early Eocene, approximately 49 million years ago. Recently discovered fossils further attest to the antiquity of the lineage leading to Zenkerella, which can now be recognized as a classic example of a “living fossil,” about which we know remarkably little. The osteological markers of gliding are estimated to have evolved along the stem lineage of the Anomalurus–Idiurus clade by the early Oligocene, potentially indicating that this adaptation evolved in response to climatic perturbations at the Eocene–Oligocene boundary (∼34 million years ago). PMID:27602286

  5. The effect of sustained natural apophyseal glide (SNAG) combined with neurodynamics in the management of a patient with cervical radiculopathy: a case report.

    PubMed

    Anandkumar, Sudarshan

    2015-02-01

    This case report describes a 47-year-old female who presented with complaints of pain in the right elbow radiating down to the thumb. Physical examination revealed symptom reproduction with Spurling A test, upper limb neurodynamic testing-1 and right cervical rotation along with reduced symptoms with neck distraction. Clinical diagnosis of cervical radiculopathy (CR) was made based on a clinical prediction rule. This case report speculates a potentially first-time description of successful conservative management of CR in a patient utilizing simultaneous combination of sustained natural apophyseal glide and neurodynamic mobilization. Immediate improvements were seen in pain, cervical range of motion and functional abilities. The patient was discharged from physical therapy by the second week after four treatment sessions with complete pain resolution maintained at a four-month follow-up period.

  6. Collaborative study report: evaluation of the ATCC experimental mycoplasma reference strains panel prepared for comparison of NAT-based and conventional mycoplasma detection methods.

    PubMed

    Dabrazhynetskaya, Alena; Volokhov, Dmitriy V; Lin, Tsai-Lien; Beck, Brian; Gupta, Rajesh K; Chizhikov, Vladimir

    2013-11-01

    The main goal of this collaborative study was to evaluate the experimental panel of cryopreserved mycoplasma reference strains recently prepared by the American Type Culture Collection (ATCC(®)) in order to assess the viability and dispersion of cells in the mycoplasma stocks by measuring the ratio between the number of genomic copies (GC) and the number of colony forming units (CFU) in the reference preparations. The employment of microbial reference cultures with low GC/CFU ratios is critical for unbiased and reliable comparison of mycoplasma testing methods based on different methodological approaches, i.e., Nucleic Acid Testing (NAT) and compendial culture-based techniques. The experimental panel included ten different mycoplasma species known to represent potential human and animal pathogens as well as common contaminants of mammalian and avian cell substrates used in research, development, and manufacture of biological products. Fifteen laboratories with expertise in field of mycoplasma titration and quantification of mycoplasmal genomic DNA participated in the study conducted from February to October of 2012. The results of this study demonstrated the feasibility of preparing highly viable and dispersed (possessing low GC/CFU ratios) frozen stocks of mycoplasma reference materials, required for reliable comparison of NAT-based and conventional mycoplasma detection methods.

  7. Displacement-Weighted Velocity Analysis of Gliding Assays Reveals that Chlamydomonas Axonemal Dynein Preferentially Moves Conspecific Microtubules

    PubMed Central

    Alper, Joshua D.; Tovar, Miguel; Howard, Jonathon

    2013-01-01

    In vitro gliding assays, in which microtubules are observed to glide over surfaces coated with motor proteins, are important tools for studying the biophysics of motility. Gliding assays with axonemal dyneins have the unusual feature that the microtubules exhibit large variations in gliding speed despite measures taken to eliminate unsteadiness. Because axonemal dynein gliding assays are usually done using heterologous proteins, i.e., dynein and tubulin from different organisms, we asked whether the source of tubulin could underlie the unsteadiness. By comparing gliding assays with microtubules polymerized from Chlamydomonas axonemal tubulin with those from porcine brain tubulin, we found that the unsteadiness is present despite matching the source of tubulin to the source of dynein. We developed a novel, to our knowledge, displacement-weighted velocity analysis to quantify both the velocity and the unsteadiness of gliding assays systematically and without introducing bias toward low motility. We found that the quantified unsteadiness is independent of tubulin source. In addition, we found that the short Chlamydomonas microtubules translocate significantly faster than their porcine counterparts. By modeling the effect of length on velocity, we propose that the observed effect may be due to a higher rate of binding of Chlamydomonas axonemal dynein to Chlamydomonas microtubules than to porcine microtubules. PMID:23663842

  8. Detection of feline Mycoplasma species in cats with feline asthma and chronic bronchitis.

    PubMed

    Schulz, Bianka S; Richter, Petra; Weber, Karin; Mueller, Ralf S; Wess, Gerhard; Zenker, Isabella; Hartmann, Katrin

    2014-12-01

    Little is known about the aetiology of inflammatory lower airway disease in cats. The aim of this study was to investigate the role of Mycoplasma species in cats with feline asthma (FA) and chronic bronchitis (CB). The study population consisted of 17 cats with FA/CB, and 14 sick cats without clinical and historical signs of respiratory disease, which were euthanased for various other reasons. Nasal swabs, nasal lavage and bronchoalveolar lavage fluid (BALF) samples were taken from patients from both groups. Mycoplasma species culture with modified Hayflick agar and Mycoplasma polymerase chain reaction (PCR) were performed on all samples followed by sequencing of all Mycoplasma species-positive samples for differentiation of subspecies. PCR testing detected significantly more Mycoplasma species-positive BALF samples than Mycoplasma culture (P = 0.021). When cats with oropharyngeal contamination were excluded from comparison, the numbers of Mycoplasma species-positive BALF samples in the group with FA/CB (6/17) and the control group (4/9) were not significantly different (P = 0.6924). While all nasal samples of the cats with FA/CB were negative for Mycoplasma organisms, five samples in the control group (P = 0.041) were positive on PCR. Sequencing revealed Mycoplasma felis in all PCR-positive samples. Mycoplasma species can be detected in the lower airways of cats with FA/CB, as well as in the BALF of sick cats without respiratory signs. Further studies are warranted to investigate the possibility that Mycoplasma species represent commensals of the lower respiratory tract of cats.

  9. Isolation and Characterization of Mycoplasma sphenisci sp. nov. from the Choana of an Aquarium-Reared Jackass Penguin (Spheniscus demersus)

    PubMed Central

    Frasca, Salvatore; Weber, E. Scott; Urquhart, Heather; Liao, Xiaofen; Gladd, Martha; Cecchini, Katharine; Hudson, Paul; May, Meghan; Gast, Rebecca J.; Gorton, Timothy S.; Geary, Steven J.

    2005-01-01

    Strain UCMJ was isolated from the choana of a jackass penguin (Spheniscus demersus) with recurrent mucocaseous choanal discharge. Isolation of this mycoplasma expands the known range of species hosting mycoplasmas. The name Mycoplasma sphenisci sp. nov. is proposed for this new species, for which strain UCMJ is the type strain. PMID:15956436

  10. Studies into the prevalence of Mycoplasma species in small ruminants in Benue State, North-central Nigeria.

    PubMed

    Akwuobu, Chinedu A; Ayling, Roger D; Chah, Kennedy Foinkfu; Oboegbulem, Stephen I

    2014-08-01

    The indicative prevalence of respiratory Mycoplasma species in small ruminants (SR) was determined in North-central Nigeria. Nasal swabs from 172 sheep and 336 goats from the Northeast, Northwest and South Senatorial Districts of Benue State were examined. Initial Mycoplasma isolation used Mycoplasma culture techniques followed by digitonin sensitivity testing. Species identification was done using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Overall, Mycoplasma organisms were isolated from 131 (25.8 %) of the 508 SR examined. Prevalence rates of 18.1 and 29.8 % were recorded for sheep and goats, respectively. A total of 135 isolates of Mycoplasma belonging to three different species were identified: Mycoplasma ovipneumoniae (127), Mycoplasma arginini (7) and Mycoplasma mycoides subspecies capri (1). More than one Mycoplasma species were detected in four (3.1 %) of the 131 confirmed Mycoplasma positive cultures. Mycoplasma was isolated from 16.2 and 29.1 % of animals with and without respiratory signs, respectively. The high isolation rate of mycoplasmas in apparently healthy and clinically sick sheep and goats in this study indicates a carrier status in these SR which may constitute a serious problem in disease control.

  11. Mycoplasma testudineum in free-ranging desert tortoises, Gopherus agassizii

    USGS Publications Warehouse

    Jacobson, Elliott R.; Berry, Kristin H.

    2012-01-01

    We performed clinico-pathological evaluations of 11 wild Agassiz's desert tortoises (Gopherus agassizii) from a translocation project in the central Mojave Desert, California, USA. Group 1 consisted of nine tortoises that were selected primarily due to serologic status, indicating exposure to Mycoplasma testudineum (seven) or both M. agassizii and M. testudineum (two), and secondarily due to clinical signs of upper respiratory tract disease (URTD). Group 2 consisted of two tortoises that were antibody-negative for Mycoplasma and had no clinical signs of URTD, but did have other signs of illness. Of the Group 1 tortoises, M. testudineum, but not M. agassizii, was amplified by polymerase chain reaction and DNA fingerprinted from two tortoises. Using light microscopy, mild to severe pathologic changes were observed in one or more histologic sections of either one or both nasal cavities of each tortoise in Group 1. Our findings support a causal relationship between M. testudineum and URTD in desert tortoises.

  12. Mycoplasmacidal activity of bovine milk for T-mycoplasmas.

    PubMed

    Brownlie, J; Howard, C J; Gourlay, R N

    1974-12-01

    Normal bovine milk and whey was mycoplasmacidal for 6 of the 13 strains of bovine T-mycoplasmas examined. The in vitro assay used also demonstrated no killing of the human, canine and simian T-mycoplasma strains after 4 hr. incubation. However, there appeared to be some cow-to-cow variation in possession of this activity, and following E. coli endotoxin stimulation of the mammary gland the activity was considerably reduced.Whey from three normal cows was fractionated on a Bio-Gel A 1.5 m. column and the mycoplasmacidal activity of the resulting five peaks assayed. Only the second peak, peak B, contained activity and was characterized as the only peak containing bovine IgA. The active component in whey, however, was found to be heat stable at 60 degrees C. for 60 minutes and to pass through a dialysis membrane. This is inconsistent with it being immunoglobulin.

  13. Detection of Mycoplasma pneumoniae by using the polymerase chain reaction.

    PubMed Central

    Bernet, C; Garret, M; de Barbeyrac, B; Bebear, C; Bonnet, J

    1989-01-01

    The polymerase chain reaction (PCR) technique was used to detect Mycoplasma pneumoniae. A specific DNA sequence for M. pneumoniae was selected from a genomic library, and two oligonucleotides were chosen in this sequence to give an amplified fragment of 144 base pairs. We show that DNA from different M. pneumoniae strains can be detected by PCR, with DNA from other Mycoplasma species giving negative results. Analysis of biological samples (throat swabs) obtained from hamsters that were experimentally infected with M. pneumoniae showed that PCR was more sensitive and reliable than conventional culture techniques for the detection of M. pneumoniae. Initial experiments on artificially seeded human bronchoalveolar lavages showed that PCR can be used to detect 10(2) to 10(3) organisms. Images PMID:2509513

  14. Phospholipids and Glycolipids of Sterol-requiring Mycoplasma

    PubMed Central

    Smith, Paul F.; Koostra, Walter L.

    1967-01-01

    The phospholipids of Mycoplasma hominis type 2 strain 07 are composed almost entirely of phosphatidyl glycerol. Traces of other glycerophospholipids may exist. No glycolipids are found. The phospholipids of Mycoplasma sp. avian strain J are composed of diphosphatidyl glycerol, which predominates in older cultures, a monoacyl glycerophosphoryl glycerophosphate, which may serve as a precursor of diphosphatidyl glycerol, and phosphatidyl glycerophosphate. This organism also contains cholesteryl glucoside and an unidentified glycolipid which appears to be similar to a monoglucosyl diglyceride. No turnover or radioisotope labeling of the phospholipids occurs during metabolism. This lack of turnover during growth is indicative of a structural role for these glycerophospholipids. A concomitant decrease of monoacyl glycerophosphoryl glycerophosphate and increase of diphosphatidyl glycerol occurs during growth. PMID:6025304

  15. [Posterior lamellar keratoplasty with DSEK technique and use of the Tan EndoGlide - short-term results].

    PubMed

    Kałuiny, Bartłomiej J; Piotrowiak, Ilona; Sołdańska, Beata; Grzybek, Katarzyna; Czajkowska, Monika; Galas, Małgorzata; Malukiewicz, Grazyna

    2013-01-01

    To present the differences in surgical technique of DSEK (Descemet's Stripping Endothelial Keratoplasty) with the use of Tan EndoGlide (Coronet, UK) and Busin Glide (Moria, FR). Short-term results will also be presented, DSEK was performed in 24 eyes, in 8 cases the surgery was combined with cataract phacoemulsification and lOL implantation. Surgery course and 6 months postoperative results of first 12 eyes performed with the use of Tan EndoGlide were compared with 12 consecutive eyes preformed with Busin Glide. Tan EndoGlide provided much more stable anterior chamber, donor tissue unfolding process was better controlled but the incision was wider incision. Surgically induced mean refractory cylinder 6. months after the surgery was 1.56 - 1.15 Dsph in Tan EndoGlide group and 1.18 +/- 1.10 Dsph in Busin Glide group (P <0.05). The endothelial cell loss was 20.5% and 21.12% respectively (P>0.05). Mean CDVA was 0.65+/- 0.27 and 0.63 +/- 0.25, respectively (P>0,05). Statistically significant differences in intra- and post-operative complications between both groups were not found. The Tan EndoGlide used during posterior lamellar keratoplasty with DSEK technique is a good alternative to currently used methods. It provides better stabilization of the anterior chamber, however its use is linked with higher postoperative astigmatism in comparison with Busin Glide. The visual outcomes and endothelial cell loss 6 months after the surgery were similar in both groups.

  16. Mycoplasma synoviae infection on Newcastle disease vaccination of chickens

    PubMed Central

    de Cássia Figueira Silva, Rita; do Nascimento, Elmiro Rosendo; de Almeida Pereira, Virgínia Léo; Barreto, Maria Lúcia; do Nascimento, Maria da Graça Fichel

    2008-01-01

    Newcastle disease is characterized by respiratory manifestations in association with nervous and/or digestive symptoms. Its prevention is done by vaccination with live attenuated (lentogenic strains) and/or killed vaccines. The lentogenic strains can lead to strong post-vaccination reaction, principally due to the presence of other pathogenic agents. Among them, Mycoplasma synoviae is worldwide important, mainly in Brazil. The dissemination of this agent in poultry flocks has been achieved due to difficulties in diagnosis and disease reproduction, virulence variations among different M.synoviae strains, and attribution of typical M.synoviae disease manifestation to other disease agents. This experimental study in SPF chicks (Gallus gallus), previously infected by M.synoviae and thereafter vaccinated against Newcastle disease, was done with the objective of evaluating M.synoviae pathogenicity through assessment of post-vaccinal respiratory reactions and serologic responses to Newcastle disease virus vaccine in the absence of environmental factors. A total of 86 three days old chicks were used, being 57 infected by eye and nostril drop, with chicken activated M. synoviae strain WVU 1853. Seven days later, 21 mycoplasma infected birds plus 29 not mycoplasma infected ones were vaccinated against Newcastle disease. As results, the not infected and vaccinated birds yielded, significantly, higher and longer lasting serologic responses to Newcastle disease vaccine virus than those infected and vaccinated. Similarly, the infected and vaccinated birds yielded lower serologic reactions to M.synoviae than those only mycoplasma infected. No post-vaccinal respiratory reaction was observed in the vaccinated birds. PMID:24031234

  17. In vitro activity of chlorhydroxyquinoline against mycoplasma species.

    PubMed

    Cosgrove, R F; Baines, S

    1978-03-01

    The in vitro activities of 5-chloro-8-hydroxyquinoline (CHQ) against single strains of 12 different species of mycoplasma and the impacts of repeated exposure of these strains to CHQ on their susceptibility to this agent have been studied. On initial exposure, the minimal inhibitory concentrations for these strains ranged from 0.24 to 1.92 micrograms of CHQ per ml of test medium; activities remained unchanged during 10 serial transfers in CHQ-containing medium.

  18. In vitro activity of chlorhydroxyquinoline against mycoplasma species.

    PubMed Central

    Cosgrove, R F; Baines, S

    1978-01-01

    The in vitro activities of 5-chloro-8-hydroxyquinoline (CHQ) against single strains of 12 different species of mycoplasma and the impacts of repeated exposure of these strains to CHQ on their susceptibility to this agent have been studied. On initial exposure, the minimal inhibitory concentrations for these strains ranged from 0.24 to 1.92 micrograms of CHQ per ml of test medium; activities remained unchanged during 10 serial transfers in CHQ-containing medium. PMID:263891

  19. A change in the genetic code in Mycoplasma capricolum

    NASA Technical Reports Server (NTRS)

    Jukes, T. H.

    1985-01-01

    Mycoplasma capricolum was previously found to use UGA instead of UGG as its codon for tryptophan and to contain 75 percent A + T in its DNA. The codon change could have been due to mutational pressure to replace C + G by A + T, resulting in the replacement of UGA stop codons by UAA, change of the anticodon in tryptophan tRNA from CCA to UCA, and replacement of UGG tryptophan codons by UGA. None of these changes should have been deleterious.

  20. A change in the genetic code in Mycoplasma capricolum

    NASA Technical Reports Server (NTRS)

    Jukes, T. H.

    1985-01-01

    Mycoplasma capricolum was previously found to use UGA instead of UGG as its codon for tryptophan and to contain 75 percent A + T in its DNA. The codon change could have been due to mutational pressure to replace C + G by A + T, resulting in the replacement of UGA stop codons by UAA, change of the anticodon in tryptophan tRNA from CCA to UCA, and replacement of UGG tryptophan codons by UGA. None of these changes should have been deleterious.