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Sample records for borreliosis group spirochete

  1. Complex population structure of Lyme borreliosis group spirochete Borrelia garinii in subarctic Eurasia.

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    Pär Comstedt

    Full Text Available Borrelia garinii, a causative agent of Lyme borreliosis in Europe and Asia, is naturally maintained in marine and terrestrial enzootic cycles, which primarily involve birds, including seabirds and migratory passerines. These bird groups associate with, correspondingly, Ixodes uriae and Ixodes ricinus ticks, of which the latter species may bite and transmit the infection to humans. Studies of the overlap between these two natural cycles of B. garinii have been limited, in part due to the absence of representative collections of this spirochete's samples, as well as of the lack of reliable measure of the genetic heterogeneity of its strains. As a prerequisite for understanding the epidemiological correlates of the complex maintenance of B. garinii, the present study sought to assess the diversity and phylogenetic relationships of this species' strains from its natural hosts and patients with Lyme borreliosis from subarctic Eurasia. We used sequence typing of the partial rrs-rrl intergenic spacer (IGS of archived and prospective samples of B. garinii from I. uriae ticks collected predominantly on Commander Islands in North Pacific, as well as on the islands in northern Sweden and arctic Norway. We also typed B. garinii samples from patients with Lyme borreliosis and I. ricinus ticks infesting migratory birds in southern Sweden, or found questing in selected sites on the islands in the Baltic Sea and Lithuania. Fifty-two (68% of 77 B. garinii samples representing wide geographical range and associated with I. ricinus and infection of humans contributed 12 (60% of total 20 identified IGS variants. In contrast, the remaining 25 (32% samples recovered from I. uriae ticks from a few islands accounted for as many as 10 (50% IGS types, suggesting greater local diversity of B. garinii maintained by seabirds and their ticks. Two IGS variants of the spirochete in common for both tick species were found in I. ricinus larvae from migratory birds, an indication

  2. Reviewing molecular adaptations of Lyme borreliosis spirochetes in the context of reproductive fitness in natural transmission cycles.

    Science.gov (United States)

    Tsao, Jean I

    2009-01-01

    Lyme borreliosis (LB) is caused by a group of pathogenic spirochetes - most often Borrelia burgdorferi, B. afzelii, and B. garinii - that are vectored by hard ticks in the Ixodes ricinus-persulcatus complex, which feed on a variety of mammals, birds, and lizards. Although LB is one of the best-studied vector-borne zoonoses, the annual incidence in North America and Europe leads other vector-borne diseases and continues to increase. What factors make the LB system so successful, and how can researchers hope to reduce disease risk - either through vaccinating humans or reducing the risk of contacting infected ticks in nature? Discoveries of molecular interactions involved in the transmission of LB spirochetes have accelerated recently, revealing complex interactions among the spirochete-tick-vertebrate triad. These interactions involve multiple, and often redundant, pathways that reflect the evolution of general and specific mechanisms by which the spirochetes survive and reproduce. Previous reviews have focused on the molecular interactions or population biology of the system. Here molecular interactions among the LB spirochete, its vector, and vertebrate hosts are reviewed in the context of natural maintenance cycles, which represent the ecological and evolutionary contexts that shape these interactions. This holistic system approach may help researchers develop additional testable hypotheses about transmission processes, interpret laboratory results, and guide development of future LB control measures and management. PMID:19368764

  3. Sensitivity of Lyme Borreliosis Spirochetes to Serum Complement of Regular Zoo Animals: Potential Reservoir Competence of Some Exotic Vertebrates.

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    Ticha, Lucie; Golovchenko, Maryna; Oliver, James H; Grubhoffer, Libor; Rudenko, Nataliia

    2016-01-01

    Reaction of vertebrate serum complement with different Borrelia burgdorferi sensu lato species is used as a basis in determining reservoir hosts among domesticated and wild animals. Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii were tested for their sensitivity to sera of exotic vertebrate species housed in five zoos located in the Czech Republic. We confirmed that different Borrelia species have different sensitivity to host serum. We found that tolerance to Borrelia infection possessed by hosts might differ among individuals of the same genera or species and is not affected by host age or sex. Of all zoo animals included in our study, carnivores demonstrated the highest apparent reservoir competency for Lyme borreliosis spirochetes. We showed that selected exotic ungulate species are tolerant to Borrelia infection. For the first time we showed the high tolerance of Siamese crocodile to Borrelia as compared to the other studied reptile species. While exotic vertebrates present a limited risk to the European human population as reservoirs for the causative agents of Lyme borreliosis, cases of incidental spillover infection could lead to successful replication of the pathogens in a new host, changing the status of selected exotic species and their role in pathogen emergence or maintenance. The question if being tolerant to pathogen means to be a competent reservoir host still needs an answer, simply because the majority of exotic animals might never be exposed to spirochetes in their natural environment. PMID:26783940

  4. Vector competence of the blacklegged tick, Ixodes scapularis, for the recently recognized Lyme borreliosis spirochete Candidatus Borrelia mayonii.

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    Dolan, Marc C; Hojgaard, Andrias; Hoxmeier, J Charles; Replogle, Adam J; Respicio-Kingry, Laurel B; Sexton, Christopher; Williams, Martin A; Pritt, Bobbi S; Schriefer, Martin E; Eisen, Lars

    2016-07-01

    A novel species within the Borrelia burgdorferi sensu lato complex, provisionally named Borrelia mayonii, was recently found to be associated with Lyme borreliosis in the Upper Midwest of the United States. Moreover, B. mayonii was detected from host-seeking Ixodes scapularis, the primary vector of B. burgdorferi sensu stricto in the eastern United States. We therefore conducted a study to confirm the experimental vector competence of I. scapularis for B. mayonii (strain MN14-1420), using colony ticks originating from adults collected in Connecticut and CD-1 white mice. Larvae fed on mice 10 weeks after needle-inoculation with B. mayonii acquired spirochetes and maintained infection through the nymphal stage at an average rate of 12.9%. In a transmission experiment, 40% of naïve mice exposed to a single infected nymph developed viable infections, as compared with 87% of mice fed upon by 2-3 infected nymphs. Transmission of B. mayonii by one or more feeding infected nymphs was uncommon up to 48h after attachment (one of six mice developed viable infection) but occurred frequently when nymphs were allowed to remain attached for 72-96h or feed to completion (11 of 16 mice developed viable infection). Mice infected via tick bite maintained viable infection with B. mayonii, as determined by ear biopsy culture, for at least 28 weeks. Our results demonstrate that I. scapularis is capable of serving as a vector of B. mayonii. This finding, together with data showing that field-collected I. scapularis are infected with B. mayonii, indicate that I. scapularis likely is a primary vector to humans of this recently recognized Lyme borreliosis spirochete. PMID:26922324

  5. Lyme borreliosis vaccination: the facts, the challenge and the future

    NARCIS (Netherlands)

    T.J. Schuijt; J.W. Hovius; T. van der Poll; A.P. van Dam; E. Fikrig

    2011-01-01

    Lyme disease, or Lyme borreliosis, the most prevalent arthropod-borne disease in the Western world, is caused by spirochetes belonging to the Borrelia burgdorferi sensu lato group and is predominantly transmitted through Ixodes ticks. There is currently no vaccine available to prevent Lyme borrelios

  6. Dissecting Lyme borreliosis; Clinical aspects, pathogenesis and prevention

    NARCIS (Netherlands)

    J. Coumou

    2016-01-01

    Lyme borreliosis (LB) is the most prevalent vector-borne disease in Western Europe and Northeastern parts of the USA. The causative agents of LB are spirochetes belonging to the Borrelia burgdorferi sensu lato group, which are transmitted by Ixodes ticks. Since the late 1970’s, researchers in the Un

  7. Laboratory aspects of Lyme borreliosis.

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    Barbour, A G

    1988-01-01

    Lyme borreliosis (Lyme disease), a common tick-borne disorder of people and domestic animals in North America and Europe, is caused by the spirochete Borrelia burgdorferi. Following the discovery and initial propagation of this agent in 1981 came revelations that other tick-associated infectious disorders are but different forms of Lyme borreliosis. A challenge for the clinician and microbiology laboratory is confirmation that a skin rash, a chronic meningitis, an episode of myocarditis, or a...

  8. Variable Tick Protein in Two Genomic Groups of the Relapsing Fever Spirochete Borrelia hermsii in Western North America

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    Porcella, Stephen F.; Raffel, Sandra J.; Anderson, Donald E.; Gilk, Stacey D.; Bono, James L.; Schrumpf, Merry E.; Schwan, Tom G.

    2005-01-01

    Borrelia hermsii is the primary cause of tick-borne relapsing fever in North America. When its tick vector, Ornithodoros hermsi, acquires these spirochetes from the blood of an infected mammal, the bacteria switch their outer surface from one of many bloodstream variable major proteins (Vmps) to a unique protein, Vtp (Vsp33). Vtp may be critical for successful tick transmission of B. hermsii; however, the gene encoding this protein has been described previously in only one isolate. Here we identified and sequenced the vtp gene in 31 isolates of B. hermsii collected over 40 years from localities throughout much of its known geographic distribution. Seven major Vtp types were found. Little or no sequence variation existed within types, but between them significant variation was observed, similar to the pattern of diversity described for the outer surface protein C (OspC) gene in Lyme disease spirochetes. The pattern of sequence relatedness among the Vtp types was incongruent in two branches compared to two genomic groups identified among the isolates by multilocus sequence typing of the 16S rRNA, flaB, gyrB, and glpQ genes. Therefore, both horizontal transfer and recombination within and between the two genomic groups were responsible for some of the variation observed in the vtp gene. O. hermsi ticks were capable of transmitting spirochetes in the newly identified genomic group. Therefore, given the longevity of the tick vector and persistent infection of spirochetes in ticks, these arthropods rather than mammals may be the likely host where the exchange of spirochetal DNA occurs. PMID:16177341

  9. Cross-Species Surface Display of Functional Spirochetal Lipoproteins by Recombinant Borrelia burgdorferi

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    Zückert, Wolfram R.; Lloyd, Jill E.; Stewart, Philip E.; Rosa, Patricia A.; Barbour, Alan G.

    2004-01-01

    Surface-exposed lipoproteins of relapsing fever (RF) and Lyme borreliosis Borrelia spirochetes mediate certain interactions of the bacteria with their arthropod and vertebrate hosts. RF spirochetes such as Borrelia hermsii serially evade the host's antibody response by multiphasic antigenic variation of Vsp and Vlp proteins. Furthermore, the expression of Vsp1 and Vsp2 by Borrelia turicatae is associated with neurotropism and higher blood densities, respectively. In contrast to RF Borrelia sp...

  10. The Cross-Talk between Spirochetal Lipoproteins and Immunity.

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    Kelesidis, Theodoros

    2014-01-01

    Spirochetal diseases such as syphilis, Lyme disease, and leptospirosis are major threats to public health. However, the immunopathogenesis of these diseases has not been fully elucidated. Spirochetes interact with the host through various structural components such as lipopolysaccharides (LPS), surface lipoproteins, and glycolipids. Although spirochetal antigens such as LPS and glycolipids may contribute to the inflammatory response during spirochetal infections, spirochetes such as Treponema pallidum and Borrelia burgdorferi lack LPS. Lipoproteins are most abundant proteins that are expressed in all spirochetes and often determine how spirochetes interact with their environment. Lipoproteins are pro-inflammatory, may regulate responses from both innate and adaptive immunity and enable the spirochetes to adhere to the host or the tick midgut or to evade the immune system. However, most of the spirochetal lipoproteins have unknown function. Herein, the immunomodulatory effects of spirochetal lipoproteins are reviewed and are grouped into two main categories: effects related to immune evasion and effects related to immune activation. Understanding lipoprotein-induced immunomodulation will aid in elucidating innate immunopathogenesis processes and subsequent adaptive mechanisms potentially relevant to spirochetal disease vaccine development and to inflammatory events associated with spirochetal diseases. PMID:25071771

  11. Tired of Lyme borreliosis: Lyme borreliosis in the Netherlands

    NARCIS (Netherlands)

    J. Coumou; T. van der Poll; P. Speelman; J.W.R. Hovius

    2011-01-01

    Lyme borreliosis has become the most common vector-borne illness in North Eastern USA and Europe. It is a zoonotic disease, with well-defined symptoms, caused by B. burgdorferi sensu lato, and transmitted by ticks. Lyme borreliosis is endemic in the Netherlands with a yearly incidence of approximate

  12. Diagnosis of Lyme Borreliosis

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    Aguero-Rosenfeld, Maria E.; Wang, Guiqing; Schwartz, Ira; Wormser, Gary P.

    2005-01-01

    A large amount of knowledge has been acquired since the original descriptions of Lyme borreliosis (LB) and of its causative agent, Borrelia burgdorferi sensu stricto. The complexity of the organism and the variations in the clinical manifestations of LB caused by the different B. burgdorferi sensu lato species were not then anticipated. Considerable improvement has been achieved in detection of B. burgdorferi sensu lato by culture, particularly of blood specimens during early stages of diseas...

  13. Treatment of Lyme borreliosis

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    Girschick, Hermann J.; Morbach, Henner; Tappe, Dennis

    2009-01-01

    Borrelia burgdorferi sensu lato is the causative agent of Lyme borreliosis in humans. This inflammatory disease can affect the skin, the peripheral and central nervous system, the musculoskeletal and cardiovascular system and rarely the eyes. Early stages are directly associated with viable bacteria at the site of inflammation. The pathogen-host interaction is complex and has been elucidated only in part. B. burgdorferi is highly susceptible to antibiotic treatment and the majority of patient...

  14. Uveitis and Lyme borreliosis.

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    Breeveld, J; Kuiper, H; Spanjaard, L.; Luyendijk, L; Rothova, A.

    1993-01-01

    In a retrospective study 56 consecutive patients with uveitis of unknown origin and 56 consecutive patients suffering from uveitis of established aetiology were investigated. The purpose of this study was to determine the frequency of positive serological tests for Lyme borreliosis among patients with uveitis and to relate laboratory data to clinical findings. The antibody titre for Borrelia burgdorferi was determined by two assays: the indirect immunofluorescence assay and the enzyme linked ...

  15. Clocking the Lyme Spirochete

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    Stephen E Malawista; de Boisfleury Chevance, Anne

    2008-01-01

    In order to clear the body of infecting spirochetes, phagocytic cells must be able to get hold of them. In real-time phase-contrast videomicroscopy we were able to measure the speed of Borrelia burgdorferi (Bb), the Lyme spirochete, moving back and forth across a platelet to which it was tethered. Its mean crossing speed was 1,636 µm/min (N = 28), maximum, 2800 µm/min (N = 3). This is the fastest speed recorded for a spirochete, and upward of two orders of magnitude above the speed of a human...

  16. Cotton wool spots as possible indicators of retinal vascular pathology in ocular lyme borreliosis.

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    Klaeger, Andres J; Herbort, Carl P

    2010-10-01

    Lyme borreliosis is an underdiagnosed infectious disease caused by a spirochete and transmitted by certain Ixodes ticks. In Lyme disease diagnostic problems are still discussed extensively as the laboratory workup is not standardized and a positive antibody result is not proof of active infection. It is therefore important to appreciate all clinical signs that can prompt us to the diagnostic investigation of Lyme borreliosis. We present a case of a woman with Lyme borreliosis and recurrent unilateral anterior uveitis in her right eye for 2 years, who developed cotton wool spots (CWS) in her left eye, followed by acute and recurrent anterior uveitis in this second eye. An extensive general examination, including blood coagulopathies and ultrasound of the carotid arteries, did not reveal any pathology. The CWS resolved within a few months. The recurrent anterior uveitis could be controlled by topical steroids. After treatment with 2 g of i.v. ceftriaxone for 3 weeks, she remained free of recurrences for 1 year of observation time. CWS can be the first clinical sign of ocular vascular pathology and/or uveitis. Further investigation will be necessary to confirm the relationship between CWS and ocular borreliosis. In patients with otherwise unexplained CWS, the possibility of an infection with borreliosis should be ruled out carefully. PMID:18854948

  17. Lyme Borreliosis and Skin

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    Biju Vasudevan; Manas Chatterjee

    2013-01-01

    Lyme disease is a multisystem illness which is caused by the strains of spirochete Borrelia burgdorferi sensu lato and transmitted by the tick, Ixodes. Though very commonly reported from the temperate regions of the world, the incidence has increased worldwide due to increasing travel and changing habitats of the vector. Few cases have been reported from the Indian subcontinent too. Skin manifestations are the earliest to occur, and diagnosing these lesions followed by appropriate treatment, ...

  18. Intermediate uveitis and Lyme borreliosis.

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    Breeveld, J; Rothova, A.; Kuiper, H

    1992-01-01

    A case of chronic intermediate uveitis and associated classic snowbanking (pars planitis) with severe cystoid macular oedema probably due to Lyme borreliosis is reported. Despite a disease duration of 10 years the patient's ocular symptoms and visual acuity responded promptly to intravenous ceftriaxone treatment. This case demonstrates that periodic reevaluation of patients with intermediate uveitis is necessary to obtain a specific diagnosis which may include Lyme borreliosis.

  19. Sustained-Release Formulation of Doxycycline Hyclate for Prophylaxis of Tick Bite Infection in a Murine Model of Lyme Borreliosis

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    Zeidner, N.S.; Brandt, K. S.; Dadey, E.; Dolan, M C; Happ, C.; Piesman, J.

    2004-01-01

    The prophylactic potential of a single injection of sustained-release doxycycline hyclate (Atridox) was compared to that of a single oral dose of doxycycline hyclate in a murine model of Lyme borreliosis. Prophylaxis, as measured by the lack of cultivable spirochetes and demonstrable pathology, was noted for 43% of orally treated mice; in contrast, the sustained-release doxycycline hyclate completely protected mice from infection and resultant pathology.

  20. Upregulation of Intercellular Adhesion Molecule 1 and Proinflammatory Cytokines by the Major Surface Proteins of Treponema maltophilum and Treponema lecithinolyticum, the Phylogenetic Group IV Oral Spirochetes Associated with Periodontitis and Endodontic Infections

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    Lee, Sung-Hoon; Kim, Kack-Kyun; Choi, Bong-Kyu

    2005-01-01

    Treponema maltophilum and Treponema lecithinolyticum belong to the group IV oral spirochetes and are associated with endodontic infections, as well as periodontitis. Recently, the genes encoding the major surface proteins (Msps) of these bacteria (MspA and MspTL, respectively) were cloned and sequenced. The amino acid sequences of these proteins showed significant similarity. In this study we analyzed the functional role of these homologous proteins in human monocytic THP-1 cells and primary ...

  1. [Borreliosis--simultaneous Lyme carditis and psychiatric disorders--case report].

    Science.gov (United States)

    Legatowicz-Koprowska, Marta; Gziut, Aneta I; Walczak, Ewa; Gil, Robert J; Wagner, Teresa

    2008-05-01

    Borreliosis is a multisystemic disease transmitted by ticks. Its diagnosis still remains a challenge because of the varied clinical picture and of difficulties in detection of the etiological agent (Borrelia burgdorferi). We report a case of a 53-years-old woman admitted to the Clinic of Cardiology due to life-threatening arhythmias with simultaneous deficits in concentration and memory. A suspicion of borreliosis was driven from the presence of cardiac symptoms as well as of psychiatric and from the case histories of a tick bite. The diagnosis was confirmed both by specific serological test and endomyocardial biopsy which revealed spirochetes. The patient responded to treatment with doxycyclin and ceftriaxone. Cardiologic disorders retreated entirely, while cognitive deficits did only partly. PMID:18634389

  2. Lyme Borreliosis: is there a preexisting (natural) variation in antimicrobial susceptibility among Borrelia burgdorferi strains?

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    Hodzic, Emir

    2015-01-01

    The development of antibiotics changed the world of medicine and has saved countless human and animal lives. Bacterial resistance/tolerance to antibiotics have spread silently across the world and has emerged as a major public health concern. The recent emergence of pan-resistant bacteria can overcome virtually any antibiotic and poses a major problem for their successful control. Selection for antibiotic resistance may take place where an antibiotic is present in the skin, gut, and other tissues of humans and animals and in the environment. Borrelia burgdorferi, the etiological agents of Lyme borreliosis, evades host immunity and establishes persistent infections in its mammalian hosts. The persistent infection poses a challenge to the effective antibiotic treatment, as demonstrated in various animal models. An increasingly heterogeneous subpopulation of replicatively attenuated spirochetes arises following treatment, and these persistent antimicrobial tolerant/resistant spirochetes are non-cultivable. The non-cultivable spirochetes resurge in multiple tissues at 12 months after treatment, with B. burgdorferi-specific DNA copy levels nearly equivalent to those found in shame-treated experimental animals. These attenuated spirochetes remain viable, but divide slowly, thereby being tolerant to antibiotics. Despite the continued non-cultivable state, RNA transcription of multiple B. burgdorferi genes was detected in host tissues, spirochetes were acquired by xenodiagnostic ticks, and spirochetal forms could be visualized within ticks and mouse tissues. A number of host cytokines were up- or down-regulated in tissues of both shame- and antibiotic-treated mice in the absence of histopathology, indicating a lack of host response to the presence of antimicrobial tolerant/resistant spirochetes. PMID:26295288

  3. [Winged scapula in lyme borreliosis].

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    Rausch, V; Königshausen, M; Gessmann, J; Schildhauer, T A; Seybold, D

    2016-06-01

    Here we present the case of a young patient with one-sided winged scapula and lyme borreliosis. This disease can be very delimitating in daily life. If non-operative treatment fails, dynamic or static stabilization of the scapula can be a therapeutic option. PMID:26849378

  4. Peripheral neuropathy in Lyme borreliosis

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    Kindstrand, Eva

    1999-01-01

    Tick-transmitted Lyme borreliosis (LB) is frequently associated with manifestations from the peripheral nervous system. One aim of the thesis was to describe the relationship between peripheral neuropathy and LB by prospective studies of a) LB in some defined neurological conditions with peripheral nerve engagement and b) peripheral neuropathy in the late dermatological LB manifestation acrodermatitis chronica atrophicans (ACA). A second aim was to evaluate the effect of ant...

  5. Borreliose de Lyme Lyme borreliosis

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    Mônica Santos; Vidal Haddad Júnior; Rodrigo Ribeiro-Rodrigues; Sinésio Talhari

    2010-01-01

    As borrelioses constituem um grupo de doenças infecciosas causadas por espiroquetas do gênero Borrelia. A borreliose de Lyme, também denominada doença de Lyme, é uma doença infecciosa, não contagiosa, causada por espiroquetas pertencentes ao complexo Borrelia burgdorferi Sensu Lato e transmitida, mais frequentemente, por picada de carrapatos do gênero Ixodes. A doença apresenta quadro clínico variado, podendo desencadear manifestações cutâneas, articulares, neurológicas e cardíacas.Borreliosi...

  6. Interaction of spirochetes with the host fibrinolytic system and potential roles in pathogenesis.

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    Vieira, Mônica Larucci; Nascimento, Ana Lucia T O

    2016-08-01

    The pathogenic spirochetes Borrelia burgdorferi, B. hermsii, B. recurrentis, Treponema denticola and Leptospira spp. are the etiologic agents of Lyme disease, relapsing fever, periodontitis and leptospirosis, respectively. Lyme borreliosis is a multi-systemic disorder and the most prevalent tick-borne disease in the northern hemisphere. Tick-borne relapsing fever is persistent in endemic areas worldwide, representing a significant burden in some African regions. Periodontal disease, a chronic inflammatory disorder that often leads to tooth loss, is caused by several potential pathogens found in the oral cavity including T. denticola. Leptospirosis is considered the most widespread zoonosis, and the predominant human disease in tropical, undeveloped regions. What these diseases have in common is that they are a significant burden to healthcare costs in the absence of prophylactic measures. This review addresses the interaction of these spirochetes with the fibrinolytic system, plasminogen (Plg) binding to the surface of bacteria and the generation of plasmin (Pla) on their surface. The consequences on host-pathogen interactions when the spirochetes are endowed with this proteolytic activity are discussed on the basis of the results reported in the literature. Spirochetes equipped with Pla activity have been shown to degrade extracellular matrix (ECM) components, in addition to digesting fibrin, facilitating bacterial invasion and dissemination. Pla generation triggers the induction of matrix metalloproteases (MMPs) in a cascade of events that enhances the proteolytic capacity of the spirochetes. These activities in concert with the interference exerted by the Plg/Pla on the complement system - helping the bacteria to evade the immune system - should illuminate our understanding of the mechanisms involved in host infection. PMID:25914944

  7. Real-time high resolution 3D imaging of the lyme disease spirochete adhering to and escaping from the vasculature of a living host.

    Directory of Open Access Journals (Sweden)

    Tara J Moriarty

    2008-06-01

    Full Text Available Pathogenic spirochetes are bacteria that cause a number of emerging and re-emerging diseases worldwide, including syphilis, leptospirosis, relapsing fever, and Lyme borreliosis. They navigate efficiently through dense extracellular matrix and cross the blood-brain barrier by unknown mechanisms. Due to their slender morphology, spirochetes are difficult to visualize by standard light microscopy, impeding studies of their behavior in situ. We engineered a fluorescent infectious strain of Borrelia burgdorferi, the Lyme disease pathogen, which expressed green fluorescent protein (GFP. Real-time 3D and 4D quantitative analysis of fluorescent spirochete dissemination from the microvasculature of living mice at high resolution revealed that dissemination was a multi-stage process that included transient tethering-type associations, short-term dragging interactions, and stationary adhesion. Stationary adhesions and extravasating spirochetes were most commonly observed at endothelial junctions, and translational motility of spirochetes appeared to play an integral role in transendothelial migration. To our knowledge, this is the first report of high resolution 3D and 4D visualization of dissemination of a bacterial pathogen in a living mammalian host, and provides the first direct insight into spirochete dissemination in vivo.

  8. A CASE OF LYME DISEASE (LYME BORRELIOSIS

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    P. Tabatabaie A. Siadati

    2006-07-01

    Full Text Available While an important infectious disease in the United States and Eurasia, Lyme disease is rare in Iran. We present a 9-year old boy admitted in Children’s Medical Center in December 2001 with final diagnosis of Lyme disease. On admission he showed arthritis and a history of previous skin lesions. Serologic examination including enzyme–linked immunosorbent assay and Western blot was positive for Lyme borreliosis. Patient was treated with doxycycline for four weeks, with good results. Although it is difficult to confirm diagnosis of Lyme disease in our patients, we should be aware that Lyme borreliosis is also found in Iran.

  9. Defensin from the ornate sheep tick Dermacentor marginatus and its effect on Lyme borreliosis spirochetes

    Czech Academy of Sciences Publication Activity Database

    Chrudimská, Tereza; Čeřovský, Václav; Slaninová, Jiřina; Rego, Ryan O. M.; Grubhoffer, Libor

    2014-01-01

    Roč. 46, č. 2 (2014), s. 165-170. ISSN 0145-305X R&D Projects: GA ČR(CZ) GAP302/11/1901 Institutional support: RVO:60077344 ; RVO:61388963 Keywords : Tick * Dermacentor marginatus * Defensin * Borrelia afzelii * Antimicrobial activity * Peptide synthesis Subject RIV: EE - Microbiology, Virology; EE - Microbiology, Virology (UOCHB-X) Impact factor: 2.815, year: 2014

  10. Lectin-binding characteristics of a Lyme borreliosis spirochete Borrelia burgdorferi sensu stricto

    Czech Academy of Sciences Publication Activity Database

    Vancová, M.; Nebesářová, J.; Grubhoffer, Libor

    2005-01-01

    Roč. 50, č. 3 (2005), s. 229-238. ISSN 0015-5632 R&D Projects: GA ČR GA206/03/1323; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * electron microscopy * lectin binding Subject RIV: EE - Microbiology, Virology Impact factor: 0.918, year: 2005

  11. Prevalence and diversity of Lyme borreliosis bacteria in marine birds.

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    Duneau, David; Boulinier, Thierry; Gómez-Díaz, Elena; Petersen, Aevar; Tveraa, Torkild; Barrett, Robert T; McCoy, Karen D

    2008-05-01

    A potential role of seabirds in spreading Lyme disease (LB) spirochetes over large spatial scales was suggested more than 10 years ago when Borrelia garinii was observed in marine birds of both hemispheres. Since then, there have been few studies examining the diversity of Borrelia spp. circulating in seabirds, or the potential interaction between terrestrial and marine disease cycles. To explore these aspects, we tested 402 Ixodes uriae ticks collected from five colonial seabird species by amplification of the flaB gene. Both the average prevalence (26.0%+/-3.9) and diversity of LB spirochetes was high. Phylogenetic analyses grouped marine isolates in two main clades: one associated with B. garinii and another with B. lusitaniae, a genospecies typically associated with lizards. One sequence also clustered most closely with B. burgdorferi sensu stricto. Prevalence in ticks varied both among seabird species within colonies and among colonies. However, there was no clear association between different Borrelia isolates and a given seabird host species. Our findings indicate that LB spirochetes circulating in the marine system are more diverse than previously described and support the hypothesis that seabirds may be an important component in the global epidemiology and evolution of Lyme disease. Future work should help determine the extent to which isolates are shared between marine and terrestrial systems. PMID:18394972

  12. Isolation and cultivation of Lyme disease spirochetes.

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    Barbour, A G

    1984-01-01

    The successful isolation and cultivation of Lyme disease spirochetes traces its lineage to early attempts at cultivating relapsing fever borreliae. Observations on the growth of Lyme disease spirochetes under different in vitro conditions may yield important clues to both the metabolic characteristics of these newly discovered organisms and the pathogenesis of Lyme disease. Images FIG. 1

  13. Forces and Torques on Rotating Spirochete Flagella

    Science.gov (United States)

    Yang, Jing; Huber, Greg; Wolgemuth, Charles W.

    2011-12-01

    Spirochetes are a unique group of motile bacteria that are distinguished by their helical or flat-wave shapes and the location of their flagella, which reside within the tiny space between the bacterial cell wall and the outer membrane (the periplasm). In Borrelia burgdorferi, rotation of the flagella produces cellular undulations that drive swimming. How these shape changes arise due to the forces and torques that act between the flagella and the cell body is unknown. It is possible that resistive forces come from friction or from fluid drag, depending on whether or not the flagella are in contact with the cell wall. Here, we consider both of these cases. By analyzing the motion of an elastic flagellum rotating in the periplasmic space, we show that the flagella are most likely separated from the bacterial cell wall by a lubricating layer of fluid. This analysis then provides drag coefficients for rotation and sliding of a flagellum within the periplasm.

  14. Gender disparity between cutaneous and non-cutaneous manifestations of Lyme borreliosis.

    Directory of Open Access Journals (Sweden)

    Franc Strle

    Full Text Available Cutaneous manifestations of Lyme borreliosis in Europe include erythema migrans (EM and acrodermatitis chronica atrophicans (ACA; the most common non-cutaneous manifestations are Lyme neuroborreliosis (LNB and Lyme arthritis. The purpose of this study was to evaluate the gender distribution of patients with these clinical manifestations of Lyme borreliosis. Data on gender were obtained from the clinical records of patients with Lyme borreliosis aged ≥15 years who had been evaluated at the University Medical Center Ljubljana, Ljubljana, Slovenia. Among 10,539 patients diagnosed with EM, 6,245 (59.3% were female and among 506 ACA patients 347 (68.6% were female. In contrast, among the 60 patients with Lyme arthritis only 15 (25% were female (p<0.0001 for the comparison of gender with EM or ACA and among the 130 patients with LNB only 51 (39.2% were females (p<0.0001for the comparison of gender with EM or ACA. Although the proportion that was female in the LNB group was greater than that of patients with Lyme arthritis, this difference did not reach statistical significance (p = 0.10. Although older individuals are more likely to be female in the general Slovenian population, the age of patients with cutaneous versus non-cutaneous manifestations was not the explanation for the observed differences in gender. In conclusion, patients with cutaneous manifestations of Lyme borreliosis were predominantly female, whereas those with non-cutaneous manifestations were predominantly male. This provocative finding is unexplained but may have direct relevance to the pathogenesis of Lyme borreliosis.

  15. The expanding spectrum of cutaneous borreliosis.

    Science.gov (United States)

    Eisendle, K; Zelger, B

    2009-04-01

    The known spectrum of skin manifestations in cutaneous Lyme disease is continuously expanding and can not be regarded as completed. Besides the classical manifestations of cutaneous borreliosis like erythema (chronicum) migrans, borrelial lymphocytoma and acrodermatitis chronica atrophicans evidence is growing that at least in part also other skin manifestations, especially morphea, lichen sclerosus and cases of cutaneous B-cell lymphoma are causally related to infections with Borrelia. Also granuloma annulare and interstitial granulomatous dermatitis might be partly caused by Borrelia burgdorferi or similar strains. There are also single reports of other skin manifestations to be associated with borrelial infections like cutaneous sarcoidosis, necrobiosis lipoidica and necrobiotic xanthogranuloma. In addition, as the modern chameleon of dermatology, cutaneous borreliosis, especially borrelial lymphocytoma, mimics other skin conditions, as has been shown for erythema annulare centrifugum or lymphocytic infiltration (Jessner Kanof) of the skin. PMID:19357623

  16. A CASE OF LYME DISEASE (LYME BORRELIOSIS)

    OpenAIRE

    P. Tabatabaie A. Siadati

    2006-01-01

    While an important infectious disease in the United States and Eurasia, Lyme disease is rare in Iran. We present a 9-year old boy admitted in Children’s Medical Center in December 2001 with final diagnosis of Lyme disease. On admission he showed arthritis and a history of previous skin lesions. Serologic examination including enzyme–linked immunosorbent assay and Western blot was positive for Lyme borreliosis. Patient was treated with doxycycline for four weeks, with good results. Although it...

  17. Filament formation associated with spirochetal infection: a comparative approach to Morgellons disease

    Directory of Open Access Journals (Sweden)

    Middelveen MJ

    2011-11-01

    Full Text Available Marianne J Middelveen, Raphael B StrickerInternational Lyme and Associated Diseases Society, Bethesda, MD, USAAbstract: Bovine digital dermatitis is an emerging infectious disease that causes lameness, decreased milk production, and weight loss in livestock. Proliferative stages of bovine digital dermatitis demonstrate keratin filament formation in skin above the hooves in affected animals. The multifactorial etiology of digital dermatitis is not well understood, but spirochetes and other coinfecting microorganisms have been implicated in the pathogenesis of this veterinary illness. Morgellons disease is an emerging human dermopathy characterized by the presence of filamentous fibers of undetermined composition, both in lesions and subdermally. While the etiology of Morgellons disease is unknown, there is serological and clinical evidence linking this phenomenon to Lyme borreliosis and coinfecting tick-borne agents. Although the microscopy of Morgellons filaments has been described in the medical literature, the structure and pathogenesis of these fibers is poorly understood. In contrast, most microscopy of digital dermatitis has focused on associated pathogens and histology rather than the morphology of late-stage filamentous fibers. Clinical, laboratory, and microscopic characteristics of these two diseases are compared.Keywords: Digital dermatitis, Morgellons disease, Lyme disease, Borrelia burgdorferi, spirochetes

  18. Detection of co-infection with Lyme spirochetes and Spotted fever group rickettsiae in a group of Haemaphysalis longicornis%一组长角血蜱中检出莱姆病螺旋体和斑点热群立克次体复合感染

    Institute of Scientific and Technical Information of China (English)

    孟真; 姜理平; 陆群英; 程苏云; 叶菊莲; 占利

    2008-01-01

    目的 了解浙江省山区野生动物和蜱中莱姆病、斑点热、埃立克体病(无形体病)的感染情况.方法 采用巢式PCR对采集的鼠、蜱标本进行莱姆病伯氏疏螺旋体、斑点热群立克次体、埃立克体(无形体)特异性核酸片段检测分析.结果 从121份鼠标本和105组蜱标本中检出阳性结果 14份.鼠标本中检出伯氏疏螺旋体5S~23S rDNA间隔区片段1份和埃立克体(无形体)16SrDNA 5'端片段2份.蜱标本中检出阳性11份,包括伯氏疏螺旋体5S~23S rDNA间隔区片段3份和斑点热群立克次体外膜蛋白OmpA基因5'端片段8份.其中1组长角血蜱成虫标本为伯氏疏螺旋体和斑点热群立克次体复合感染,5S~23S rRNA基因间隔区和ompA基因片段均阳性,分别与伯氏疏螺旋体法雷氏基因型和马赛立克次体株等关系较近.结论 在同一组长角血蜱成虫中同时检出莱姆病疏螺旋体和斑点热群立克次体复合感染.%Objective The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis (anaplasmosisin) in wild animals and ticks in the mountain areas of Zhejiang province. Methods Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia (anaplasma) from samples of mice and ticks. Results 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borreia burgdorferi and two 5' fragments of Ehrlichia (anaplasma) 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borreia burgdorferi and eight 5' fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and

  19. Phylogenetic position of the spirochetal genus Cristispira

    DEFF Research Database (Denmark)

    Paster, B.J.; Pelletier, D.A.; Dewhirst, F.E.;

    1996-01-01

    a cell-laden crystalline styles of the oyster Crassostrea virginica. The amplified products were then cloned into Escherichia coli plasmids. Sequence comparisons of the gene coding for 16S rRNA (rDNA) insert of one clone, designated CP1, indicated that it was spirochetal. The sequence of the 16S rDNA...... insert of another clone was mycoplasmal. The CP1 sequence possessed most of the individual base signatures that are unique to 16S rRNA (or rDNA) sequences of known spirochetes. CP1 branched deeply among other spirochetal genera within the family Spirochaetaceae, and accordingly, it represents a separate......Comparative sequence analysis of 16S rRNA genes was used to determine the phylogenetic relationship of the genus Cristispira to other spirochetes. Since Cristispira organisms cannot presently be grown in vitro, 16S rRNA genes were amplified directly from bacterial DNA isolated from Cristispira...

  20. Association of spirochetal infection with Morgellons disease.

    Science.gov (United States)

    Middelveen, Marianne J; Burugu, Divya; Poruri, Akhila; Burke, Jennie; Mayne, Peter J; Sapi, Eva; Kahn, Douglas G; Stricker, Raphael B

    2013-01-01

    Morgellons disease (MD) is an emerging multisystem illness characterized by skin lesions with unusual filaments embedded in or projecting from epithelial tissue. Filament formation results from abnormal keratin and collagen expression by epithelial-based keratinocytes and fibroblasts. Recent research comparing MD to bovine digital dermatitis, an animal infectious disease with similar skin features, provided clues that spirochetal infection could play an important role in the human disease as it does in the animal illness. Based on histological staining, immunofluorescent staining, electron microscopic imaging and polymerase chain reaction, we report the detection of Borrelia spirochetes in dermatological tissue of  four randomly-selected MD patients. The association of MD with spirochetal infection provides evidence that this infection may be a significant factor in the illness and refutes claims that MD lesions are self-inflicted and that people suffering from this disorder are delusional. Molecular characterization of the Borrelia spirochetes found in MD patients is warranted. PMID:24715950

  1. Relapsing Fever Spirochetes Retain Infectivity After Prolonged in vitro Cultivation

    Science.gov (United States)

    Schrumpf, Merry E.; Raffel, Sandra J.; Policastro, Paul F.; Porcella, Stephen F.; Schwan, Tom G.

    2008-01-01

    Abstract Borrelia hermsii and Borrelia burgdorferi, two closely related spirochetes, are the etiological agents of tick-borne relapsing fever and Lyme disease, respectively. Previous studies have shown the loss of infectivity of B. burgdorferi is associated with in vitro cultivation. This diminished infectivity of B. burgdorferi has occurred as early as three in vitro passages, and the loss of plasmids have been observed with these less virulent to noninfective cultures. The effects of long-term in vitro cultivation on B. hermsii have not been investigated. However, understanding the degree of genomic degradation during in vitro cultivation is important for investigating pathogenic mechanisms of spirochetes. In this study, we analyzed the effects of continuous in vitro cultivation on the genomic composition and infectivity of B. hermsii and B. turicatae. We report that all seven isolates of B. hermsii and the one isolate of B. turicatae examined retained infectivity in mice after 1 year of continuous in vitro cultivation. Furthermore, there were few apparent differences in the plasmid profiles after long-term cultivation. Two isolates of B. hermsii remained infective after high passage despite losing a portion of the 200-kb linear plasmid containing the fhbA gene encoding the factor H binding protein. Also, sequence analysis of multiple B. hermsii isolates demonstrated two types of fhbA with complete congruence with the two genomic groups of B. hermsii spirochetes. Therefore, these results suggest that relapsing fever spirochetes are genetically stable during in vitro cultivation, and the fhbA-containing segment of DNA that is lost during cultivation is not required for infection. PMID:18637723

  2. Determinants of the geographic distribution of Puumala virus and Lyme borreliosis infections in Belgium

    Directory of Open Access Journals (Sweden)

    Tersago Katrien

    2007-05-01

    Full Text Available Abstract Background Vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. Land cover and land use influence disease transmission by controlling both the spatial distribution of vectors or hosts, and the probability of contact with susceptible human populations. The objective of this study was to combine environmental and socio-economic factors to explain the spatial distribution of two emerging human diseases in Belgium, Puumala virus (PUUV and Lyme borreliosis. Municipalities were taken as units of analysis. Results Negative binomial regressions including a correction for spatial endogeneity show that the spatial distribution of PUUV and Lyme borreliosis infections are associated with a combination of factors linked to the vector and host populations, to human behaviours, and to landscape attributes. Both diseases are associated with the presence of forests, which are the preferred habitat for vector or host populations. The PUUV infection risk is higher in remote forest areas, where the level of urbanisation is low, and among low-income populations. The Lyme borreliosis transmission risk is higher in mixed landscapes with forests and spatially dispersed houses, mostly in wealthy peri-urban areas. The spatial dependence resulting from a combination of endogenous and exogenous processes could be accounted for in the model on PUUV but not for Lyme borreliosis. Conclusion A large part of the spatial variation in disease risk can be explained by environmental and socio-economic factors. The two diseases not only are most prevalent in different regions but also affect different groups of people. Combining these two criteria may increase the efficiency of information campaigns through appropriate targeting.

  3. DNA characterization of Lyme disease spirochetes.

    OpenAIRE

    Schmid, G P; Steigerwalt, A G; Johnson, S; Barbour, A G; Steere, A. C.; Robinson, I M; Brenner, D J

    1984-01-01

    Lyme disease spirochetes (LDS) have phenotypic characteristics of both treponemes and borreliae. To ascertain whether one or more species of LDS exist, as well as their taxonomic status, we determined the DNA base (G + C) content for three strains of LDS, the DNA relatedness of ten strains isolated in the United States or Europe, and the DNA relatedness of LDS to other spirochetes. The G + C content of the three LDS strains was 28.1-29.0 mol%, most similar to those of Borellia hermsii (30.6 m...

  4. Characterization of a Novel Relapsing Fever Spirochete in the Midgut, Coxal Fluid, and Salivary Glands of the Bat Tick Carios kelleyi

    Science.gov (United States)

    Raffel, Sandra J.; Schrumpf, Merry E.; Gill, James S.; Piesman, Joseph

    2009-01-01

    Abstract Bat ticks, Carios kelleyi, from Iowa were examined for the presence of relapsing fever group borreliae. A novel spirochete was characterized by DNA sequence analysis of polymerase chain reaction amplicons for the 16S rRNA, flaB, and glpQ genes in either triturated tick pools or single ticks. All loci and the concatenated DNA sequence of 3,289 bases identified the Carios bacterium as a relapsing fever spirochete most closely related to, but distinct from, Borrelia turicatae. Spirochetes reactive with a Borrelia-specific monoclonal antibody were observed microscopically in the coxal fluid and salivary glands from one tick. These data confirm the presence of a novel species of relapsing fever spirochete in bat ticks and the potential for new enzootic foci for endemic relapsing fever that warrants further investigation. The name Borrelia johnsonii is proposed for this novel spirochete in honor of Dr. Russell C. Johnson. PMID:19281412

  5. Filament formation associated with spirochetal infection: a comparative approach to Morgellons disease.

    Science.gov (United States)

    Middelveen, Marianne J; Stricker, Raphael B

    2011-01-01

    Bovine digital dermatitis is an emerging infectious disease that causes lameness, decreased milk production, and weight loss in livestock. Proliferative stages of bovine digital dermatitis demonstrate keratin filament formation in skin above the hooves in affected animals. The multifactorial etiology of digital dermatitis is not well understood, but spirochetes and other coinfecting microorganisms have been implicated in the pathogenesis of this veterinary illness. Morgellons disease is an emerging human dermopathy characterized by the presence of filamentous fibers of undetermined composition, both in lesions and subdermally. While the etiology of Morgellons disease is unknown, there is serological and clinical evidence linking this phenomenon to Lyme borreliosis and coinfecting tick-borne agents. Although the microscopy of Morgellons filaments has been described in the medical literature, the structure and pathogenesis of these fibers is poorly understood. In contrast, most microscopy of digital dermatitis has focused on associated pathogens and histology rather than the morphology of late-stage filamentous fibers. Clinical, laboratory, and microscopic characteristics of these two diseases are compared. PMID:22253541

  6. Association of spirochetal infection with Morgellons disease

    OpenAIRE

    Middelveen, Marianne J; Divya Burugu; Akhila Poruri; Jennie Burke; Mayne, Peter J; Eva Sapi; Douglas G Kahn; Stricker, Raphael B.

    2013-01-01

    Morgellons disease (MD) is an emerging multisystem illness characterized by skin lesions with unusual filaments embedded in or projecting from epithelial tissue. Filament formation results from abnormal keratin and collagen expression by epithelial-based keratinocytes and fibroblasts. Recent research comparing MD to bovine digital dermatitis, an animal infectious disease with similar skin features, provided clues that spirochetal infection could play an important role in the human disease as ...

  7. The unique paradigm of spirochete motility and chemotaxis

    OpenAIRE

    Charon, Nyles W.; Cockburn, Andrew; Li, Chunhao; Liu, Jun; Miller, Kelly A.; MILLER, MICHAEL R.; Motaleb, Md.; Wolgemuth, Charles W.

    2012-01-01

    Spirochete motility is enigmatic: It differs from the motility of most other bacteria in that the entire bacterium is involved in translocation in the absence of external appendages. Using the Lyme disease spirochete Borrelia burgdorferi (Bb) as a model system, we explore the current research on spirochete motility and chemotaxis. Bb has periplasmic flagella (PFs) subterminally attached to each end of the protoplasmic cell cylinder, and surrounding the cell is an outer membrane. These interna...

  8. Lyme disease spirochetes and ixodid tick spirochetes share a common surface antigenic determinant defined by a monoclonal antibody.

    OpenAIRE

    Barbour, A. G; Tessier, S L; Todd, W J

    1983-01-01

    Ixodid tick-associated spirochetes have been implicated as the etiological agents of Lyme disease. We raised a murine monoclonal antibody (H5332) against a spirochete, strain B31, isolated from Ixodes dammini ticks. In indirect immunofluorescence assays and western blot analyses, H5332 reacted with whole cells or isolated components of not only strain B31 but also spirochetes isolated from Ixodes ricinus ticks, a field mouse, a raccoon, and patients with Lyme disease. In contrast, H5332 did n...

  9. Ribotyping on small-sized spirochetes isolated from subgingival plaque

    DEFF Research Database (Denmark)

    Fiehn, N E; Bangsborg, J M; Colding, H

    1995-01-01

    In the present study DNA restriction patterns and corresponding ribotypes of 17 subgingival small-sized spirochetes (1:2:1 and 2:4:2 isolates), 2 Treponema socranskii strains and two Treponema denticola strains were examined. Purified chromosomal DNA was digested by BamHI, HindIII, PstI and Cla...... distinct bands were observed after digestion with HindIII, whereas a maximum of 6 bands were observed when PstI or ClaI was used. By using ClaI, the examined 1:2:1 isolates were separated into 8 groups, whereas PstI and HindIII separated these isolates into 5 groups. The ribotyping showed that the tested 1...

  10. Lyme borreliosis : reviewing potential vaccines, clinical aspects and health economics

    NARCIS (Netherlands)

    Smit, Renata; Postma, Maarten J.

    2015-01-01

    Lyme borreliosis (LB) is a multisystem infectious disease with a growing burden in many parts of North America, Asia and Europe. Persistent infection of LB can usually be treated effectively with antibiotic therapy, but it may be followed by post-treatment Lyme disease syndrome. Therefore, it is imp

  11. Phylogeny of not-yet-cultured spirochetes from termite guts

    DEFF Research Database (Denmark)

    Paster, B.J.; Dewhirst, F.E.; Cooke, S.M.;

    1996-01-01

    Comparisons of 16S rDNA sequences were used to determine the phylogeny of not-yet-cultured spirochetes from hindguts of the African higher termite, Nasutitermes lujae (Wasmann). The 16S rRNA genes were amplified directly from spirochete-rich hindguts by using universal primers, and the amplified...

  12. Phylogenetic position of the spirochetal genus Cristispira

    DEFF Research Database (Denmark)

    Paster, B.J.; Pelletier, D.A.; Dewhirst, F.E.; Weisburg, W.G.; Fussing, V.; Poulsen, Lars K.; Dannenberg, S.; Schroeder, I.

    1996-01-01

    Comparative sequence analysis of 16S rRNA genes was used to determine the phylogenetic relationship of the genus Cristispira to other spirochetes. Since Cristispira organisms cannot presently be grown in vitro, 16S rRNA genes were amplified directly from bacterial DNA isolated from Cristispira a...... genus within this family. A fluorescently labeled DNA probe designed from the CP1 sequence was used for in situ hybridization experiments to verify that the sequence obtained was derived from the observed Cristispira cells....

  13. Cryptic vector divergence masks vector-specific patterns of infection: an example from the marine cycle of Lyme borreliosis.

    Science.gov (United States)

    Gómez-Díaz, Elena; Doherty, Paul F; Duneau, David; McCoy, Karen D

    2010-07-01

    Vector organisms are implicated in the transmission of close to a third of all infectious diseases. In many cases, multiple vectors (species or populations) can participate in transmission but may contribute differently to disease ecology and evolution. The presence of cryptic vector populations can be particularly problematic as differences in infection can be difficult to evaluate and may lead to erroneous evolutionary and epidemiological inferences. Here, we combine site-occupancy modeling and molecular assays to evaluate patterns of infection in the marine cycle of Lyme borreliosis, involving colonial seabirds, the tick Ixodes uriae, and bacteria of the Borrelia burgdorferi s.l. complex. In this cycle, the tick vector consists of multiple, cryptic (phenotypically undistinguishable but genetically distinct) host races that are frequently found in sympatry. Our results show that bacterial detection varies strongly among tick races leading to vector-specific biases if raw counts are used to calculate Borrelia prevalence. These differences are largely explained by differences in infection intensity among tick races. After accounting for detection probabilities, we found that overall prevalence in this system is higher than previously suspected and that certain vector-host combinations likely contribute more than others to the local dynamics and large-scale dispersal of Borrelia spirochetes. These results highlight the importance of evaluating vector population structure and accounting for detection probability when trying to understand the evolutionary ecology of vector-borne diseases. PMID:25567933

  14. Evaluation of Borrelia burgdorferi BbHtrA Protease as a Vaccine Candidate for Lyme Borreliosis in Mice.

    Directory of Open Access Journals (Sweden)

    Amy J Ullmann

    Full Text Available Borrelia burgdorferi synthesizes an HtrA protease (BbHtrA which is a surface-exposed, conserved protein within Lyme disease spirochetes with activity toward CheX and BmpD of Borrelia spp, as well as aggrecan, fibronectin and proteoglycans found in skin, joints and neural tissues of vertebrates. An antibody response against BbHtrA is observed in Lyme disease patients and in experimentally infected laboratory mice and rabbits. Given the surface location of BbHtrA on B. burgdorferi and its ability to elicit an antibody response in infected hosts, we explored recombinant BbHtrA as a potential vaccine candidate in a mouse model of tick-transmitted Lyme disease. We immunized mice with two forms of BbHtrA: the proteolytically active native form and BbHtrA ablated of activity by a serine to alanine mutation at amino acid 226 (BbHtrA(S226A. Although inoculation with either BbHtrA or BbHtrA(S226A produced high-titer antibody responses in C3H/HeJ mice, neither antigen was successful in protecting mice from B. burgdorferi challenge. These results indicate that the search for novel vaccine candidates against Lyme borreliosis remains a challenge.

  15. Travelling between Two Worlds: Complement as a Gatekeeper for an Expanded Host Range of Lyme Disease Spirochetes

    Directory of Open Access Journals (Sweden)

    Peter Kraiczy

    2016-06-01

    Full Text Available Evading innate immunity is a prerequisite for pathogenic microorganisms in order to survive in their respective hosts. Concerning Lyme disease spirochetes belonging to the Borrelia (B. burgdorferi sensu lato group, a broad range of diverse vertebrates serve as reservoir or even as incidental hosts, including humans. The capability to infect multiple hosts implies that spirochetes have developed sophisticated means to counter the destructive effects of complement of humans and various animals. While the means by which spirochetes overcome the hosts immune defense are far from being completely understood, there is a growing body of evidence suggesting that binding of the key regulator of the alternative pathway, Factor H, plays a pivotal role for immune evasion and that Factor H is an important determinant of host specificity. This review covers (i the contribution of complement in host-specificity and transmissibility of Lyme disease spirochetes; (ii the involvement of borrelial-derived determinants to host specificity; (iii the interplay of human and animal Factor H with complement-acquiring surface proteins of diverse borrelial species; and (iv the potential role of additional animal complement proteins in the immune evasion of spirochetes.

  16. Tick-Borne Relapsing Fever Spirochetes in the Americas

    Directory of Open Access Journals (Sweden)

    Job E. Lopez

    2016-08-01

    Full Text Available Relapsing fever spirochetes are tick- and louse-borne pathogens that primarily afflict those in impoverished countries. Historically the pathogens have had a significant impact on public health, yet currently they are often overlooked because of the nonspecific display of disease. In this review, we discuss aspects of relapsing fever (RF spirochete pathogenesis including the: (1 clinical manifestation of disease; (2 ability to diagnose pathogen exposure; (3 the pathogen’s life cycle in the tick and mammal; and (4 ecological factors contributing to the maintenance of RF spirochetes in nature.

  17. Swimming Dynamics of the Lyme Disease Spirochete

    Science.gov (United States)

    Vig, Dhruv K.; Wolgemuth, Charles W.

    2012-11-01

    The Lyme disease spirochete, Borrelia burgdorferi, swims by undulating its cell body in the form of a traveling flat wave, a process driven by rotating internal flagella. We study B. burgdorferi’s swimming by treating the cell body and flagella as linearly elastic filaments. The dynamics of the cell are then determined from the balance between elastic and resistive forces and moments. We find that planar, traveling waves only exist when the flagella are effectively anchored at both ends of the bacterium and that these traveling flat waves rotate as they undulate. The model predicts how the undulation frequency is related to the torque from the flagellar motors and how the stiffness of the cell body and flagella affect the undulations and morphology.

  18. PERIPHERAL FACIAL PALSY IN CHILDHOOD - LYME BORRELIOSIS TO BE SUSPECTED UNLESS PROVEN OTHERWISE

    NARCIS (Netherlands)

    CHRISTEN, HJ; BARTLAU, N; HANEFELD, F; EIFFERT, H; THOMSSEN, R

    1990-01-01

    27 consecutive cases with acute peripheral facial palsy were studied for Lyme borreliosis. In 16 out of 27 children Lyme borreliosis could be diagnosed by detection of specific IgM antibodies in CSF. CSF findings allow a clear distinction according to etiology. All children with facial palsy due to

  19. Serum carnitine concentration is decreased in patients with Lyme borreliosis

    Directory of Open Access Journals (Sweden)

    Alina Kępka

    2016-03-01

    Full Text Available Background: Lyme borreliosis (LB is a serious infectious disease. Carnitine plays a crucial role in metabolism and inflammatory responses. Carnitine may be important in improving neuronal dysfunction and loss of neurons. Aim: To evaluate serum carnitine concentration in adult patients with various clinical types of LB. Material/Methods: Groups: 1 patients with erythema migrans (EM, n=16, 2 neuroborreliosis (NB, n=10, 3 post-Lyme disease (PLD, n=22 and healthy controls (HC, n=32. Total (TC and free (FC carnitine were determined with the spectrophotometric method. Results: TC levels (44.9±10.4, 28.0±8.4, 35.9±15.6 μmol/L in the EM, NB and PLD patients were lower than in HC (54.0±11.4 μmol/L, p < 0.001. FC levels (32.7±7.7, 23.6±6.8, 26.3±11.2 μmol/L in the EM, NB and PLD patients were lower than in HC (40.5±7.6 μmol/L, p < 0.001. AC levels (12.2±5.2, 4.4±2.6, 9.6±7.4 μmol/L in the EM, NB and PLD patients were lower in the NB and PLD patients than in HC (13.5±8.40 μmol/L, p <0.001. AC/FC ratio was 0.31±0.14, 0.18±0.09, 0.39±0.33 in the EM, NB and PLD patients. Conclusions: LB patients exhibit a significant decrease of their serum carnitine concentrations. The largest changes were in the NB and PLD patients. To prevent late complications of the disease a possibility of early supplementation with carnitine should be considered. Further studies are required to explain the pathophysiological significance of our findings.

  20. Enfermedad de Lyme (Borreliosis de Lyme en Costa Rica Lyme disease in Costa Rica, a case report

    Directory of Open Access Journals (Sweden)

    Ricardo Boza-Cordero

    2011-01-01

    Full Text Available La enfermedad de Lyme o borreliosis de Lyme es una zoonosis transmitida por garrapatas del género Ixodes y producida por la espiroqueta Borrelia burgdorferi. Ha sido descrita principalmente en Norteamérica, Europa y Asia, y se caracteriza clínicamente por una presentación en tres etapas: inicial con eritema migrans que comienza alrededor de la picadura de la garrapata; infección diseminada con fiebre, ataque al estado general, artritis migratoria, linfadenopatías, alteraciones neurológicas y hepatitis; y la forma crónica, caracterizada por artritis, periostitis, encefalomielitis crónica y polirradiculopatía, entre otras manifestaciones. En Costa Rica se desconocen notificaciones de pacientes con esta patología, por lo que se presenta el caso de una mujer adulta que tras un viaje al Estado de La Florida en los Estados Unidos, presentó cuadro clínico y serológico compatible con la forma leve de la enfermedad de Lyme. Se discuten los hallazgos y se alerta sobre la posibilidad de diagnosticar esta zoonosis, dado el auge del turismo ecológico en estos días.Lyme disease or Lyme borreliosis is a zoonosis transmitted by the Ixodes ticks and caused by a spirochete Borrelia burgdorferi. It has been reported mostly in North America, Europe and Asia and is clinically characterized by a presentation on 3 stages, starting with erythema migrans that begins around the tick bite. Disseminated infection with fever, migratory arthritis, lymphadenopathy, neurological alterations and hepatitis and the chronic phase characterized by arthritis, periostitis, chronic encephalomielitis, polyradiculopathy amongst other manifestations. In Costa Rica, we know of no reports of patients with this disease, so we herein present the case of an woman who, after a trip to the state of Florida, presented clinical and serological alterations compatible with the mild form of Lyme disease. The findings are discussed and also we alert to the possibility of diagnosing

  1. Interaction of spirochetes with the host.

    Science.gov (United States)

    Hindersson, P; Thomas, D; Stamm, L; Penn, C; Norris, S; Joens, L A

    1992-01-01

    The success of an invading organism must depend on several cytoplasmic, surface-associated and secreted factors. The technical difficulties in handling pathogenic spirochetes like Treponema pallidum and Borrelia burgdorferi have made it difficult to define specific factors involved in entry and long-term survival. The problem of defining virulence factors has been attacked by several strategies: T. pallidum secretes a number of immunogenic low molecular mass proteins. The most predominant are of molecular weight 15.5 and 22 kDa. Preliminary data suggest that antibodies against these proteins induce protective immunity in rabbits experimentally infected with T. pallidum. Many potentially important surface-associated antigens of T. pallidum have now been cloned and characterized. Two of these, TpD and TpE, are lipoproteins which exhibit characteristic size heterogeneity. The apparent molecular weight of TpE from T. pallidum and T. pertenue are different. The clinical symptoms in syphilis and yaws are very different, but sequence analysis of TpE has shown that the TpE proteins are indeed very similar in the two strains. This observation makes it unlikely that heterogeneity of TpE can account for the different clinical symptoms of syphilis and yaws. Sequence data for another newly sequenced surface-associated antigen of T. pallidum (molecular weight 41 kDa) indicate that this protein is involved in glucose transport and chemotaxis/motility. Intracellular factors like the molecular chaperonin GroEL have been documented both in treponemes and borreliae. This stress protein is involved in cellular repair processes and folding/assembly of protein subunits. Indirect evidence suggests that GroEL affects the ability of spirochetes to survive in the stressful environment of the infected host. Several lines of evidence suggest that the Osp proteins of Borrelia are important for host/parasite interaction. Further support for this idea has come from studies of a series of

  2. Postinfectious syndrome of convalescentsixodes tick-borne borreliosis

    Directory of Open Access Journals (Sweden)

    O. N. Sumlivaya

    2014-01-01

    Full Text Available The aim: to study the psycho-vegetative status of the quantitative contents of serotonin in blood platelets in patients after the Ixodes tick-borne borreliosis, to evaluate the clinical efficiency treatment by adamantilfenilamin of postinfection asthenia.Materials and methods: there was clinical supervision and inspection conducted of 118 convalescents borreliosis after a course of inpatient treatment. All patients were examined using psychovegetative tests. Platelet serotonin concentration levels were measured by enzyme immunoassay. For the treatment of postinfectious asthenia 36 convalescents received adamantilbromfenilamin in a dose of 100 mg for 25 days.Results: when tested convalescents marked change in indicators of emotional and personality disorders. Quantitative study of blood platelet serotonin content revealed a significant decrease in this indicator relative to control values. Study the correlations between obtained when testing the psycho-emotional parameters and platelet serotonin levels showed a negative correlation between serotonin and an indicator of reactive anxiety (R = -0,81, p <0,05. To correct these violations convalescents with severe asthenia postinfection were treated adamantilfenilamin. Established clinical efficacy contributing to the improvement of the quality of life.Conclusion: the research of neurotransmitter serotonin in patients during the convalescence period after borreliosis possible to evaluate the extent of potential damage to the nervous tissue in the inflammatory process and its involvement in the formation of anxiety and depressive symptoms. adamantilbromfenilamin can be recommended for rehabilitation patients with residual effects in the form of postinfectious asthenia.

  3. Enfermedad de Lyme (Borreliosis de Lyme) en Costa Rica

    OpenAIRE

    Ricardo Boza-Cordero

    2011-01-01

    La enfermedad de Lyme o borreliosis de Lyme es una zoonosis transmitida por garrapatas del género Ixodes y producida por la espiroqueta Borrelia burgdorferi. Ha sido descrita principalmente en Norteamérica, Europa y Asia, y se caracteriza clínicamente por una presentación en tres etapas: inicial con eritema migrans que comienza alrededor de la picadura de la garrapata; infección diseminada con fiebre, ataque al estado general, artritis migratoria, linfadenopatías, alteraciones neurológicas y ...

  4. Prevalence and diversity of Lyme borreliosis bacteria in marine birds

    OpenAIRE

    Duneau, David; Boulinier, T.; Gomez Diaz, E.; Petersen, A.; Tveraa, Torkild; Barrett, R. T.; McCoy, Karen

    2008-01-01

    A potential role of seabirds in spreading Lyme disease (LB) spirochetes over large spatial scales was suggested more than 10 years ago when Borrelia garinii was observed in marine birds of both hemispheres. Since then, there have been few studies examining the diversity of Borrelia spp. circulating in seabirds, or the potential interaction between terrestrial and marine disease cycles. To explore these aspects, we tested 402 Ixodes uriae ticks collected from five colonial seabird species by a...

  5. Elimination of Lyme Disease Spirochetes from Ticks Feeding on Domestic Ruminants▿

    OpenAIRE

    Richter, Dania; Matuschka, Franz-Rainer

    2010-01-01

    To determine whether and which spirochetes are cleared from Ixodes ricinus ticks during feeding on ruminants, ticks were removed from goats and cattle grazing on tick-infested pastures. Although about a quarter of ticks questing on the pasture were infected by spirochetes, no molted ticks that had previously engorged to repletion on ruminants harbored Lyme disease spirochetes. Borrelia miyamotoi spirochetes, however, appear not to be eliminated. Thus, the more subadult ticks are diverted from...

  6. The diagnostic accuracy of serological tests for Lyme borreliosis in Europe

    DEFF Research Database (Denmark)

    Leeflang, M M G; Ang, C W; Berkhout, J;

    2016-01-01

    BACKGROUND: Interpretation of serological assays in Lyme borreliosis requires an understanding of the clinical indications and the limitations of the currently available tests. We therefore systematically reviewed the accuracy of serological tests for the diagnosis of Lyme borreliosis in Europe....... METHODS: We searched EMBASE en MEDLINE and contacted experts. Studies evaluating the diagnostic accuracy of serological assays for Lyme borreliosis in Europe were eligible. Study selection and data-extraction were done by two authors independently. We assessed study quality using the QUADAS-2 checklist...... % CI 40 % to 61 %); neuroborreliosis 77 % (95 % CI 67 % to 85 %); acrodermatitis chronica atrophicans 97 % (95 % CI 94 % to 99 %); unspecified Lyme borreliosis 73 % (95 % CI 53 % to 87 %). Specificity was around 95 % in studies with healthy controls, but around 80 % in cross-sectional studies. Two...

  7. Complete genome sequence of Treponema pallidum, the syphilis spirochete.

    Science.gov (United States)

    Fraser, C M; Norris, S J; Weinstock, G M; White, O; Sutton, G G; Dodson, R; Gwinn, M; Hickey, E K; Clayton, R; Ketchum, K A; Sodergren, E; Hardham, J M; McLeod, M P; Salzberg, S; Peterson, J; Khalak, H; Richardson, D; Howell, J K; Chidambaram, M; Utterback, T; McDonald, L; Artiach, P; Bowman, C; Cotton, M D; Fujii, C; Garland, S; Hatch, B; Horst, K; Roberts, K; Sandusky, M; Weidman, J; Smith, H O; Venter, J C

    1998-07-17

    The complete genome sequence of Treponema pallidum was determined and shown to be 1,138,006 base pairs containing 1041 predicted coding sequences (open reading frames). Systems for DNA replication, transcription, translation, and repair are intact, but catabolic and biosynthetic activities are minimized. The number of identifiable transporters is small, and no phosphoenolpyruvate:phosphotransferase carbohydrate transporters were found. Potential virulence factors include a family of 12 potential membrane proteins and several putative hemolysins. Comparison of the T. pallidum genome sequence with that of another pathogenic spirochete, Borrelia burgdorferi, the agent of Lyme disease, identified unique and common genes and substantiates the considerable diversity observed among pathogenic spirochetes. PMID:9665876

  8. Isolation of Borrelia spirochetes from patients in Texas.

    OpenAIRE

    Rawlings, J A; Fournier, P V; Teltow, G. J.

    1987-01-01

    The Texas Department of Health Laboratory began culturing the Lyme disease spirochete Borrelia burgdorferi in 1985. This organism was subsequently isolated from blood, cerebrospinal fluid, joint fluid, skin, bone, and autopsy tissues from humans. Fluorescent-antibody tests with murine monoclonal antibodies confirmed that seven of these isolates were B. burgdorferi and that two others belonged to the genus Borrelia.

  9. Lyme borreliosis: insights into tick- / host-borrelia relations

    Czech Academy of Sciences Publication Activity Database

    Grubhoffer, Libor; Golovchenko, Maryna; Vancová, Marie; Zacharovová, Klára; Rudenko, Natalia; Oliver, J. H., Jr.

    2005-01-01

    Roč. 52, č. 4 (2005), s. 279-294. ISSN 0015-5683 R&D Projects: GA ČR GA524/03/1326; GA ČR GA206/03/1323 Grant ostatní: National Institutes of Health(US) R37 AI-24899; Science and Technology Collaboration AVCR-NRC Canada(CZ) Z60220518/58-8500 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia spirochetes * ticks * lectins * glycoproteins Subject RIV: EE - Microbiology, Virology Impact factor: 1.138, year: 2005

  10. Mapping human risk of infection with Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, in a periurban forest in France.

    Science.gov (United States)

    Vourc'h, G; Abrial, D; Bord, S; Jacquot, M; Masséglia, S; Poux, V; Pisanu, B; Bailly, X; Chapuis, J-L

    2016-07-01

    Lyme borreliosis is a major zoonosis in Europe, with estimates of over 26,000 cases per year in France alone. The etiological agents are spirochete bacteria that belong to the Borrelia burgdorferi sensu lato (s. l.) complex and are transmitted by hard ticks among a large range of vertebrate hosts. In Europe, the tick Ixodes ricinus is the main vector. In the absence of a vaccine and given the current difficulties to diagnose and treat chronic Lyme syndromes, there is urgent need for prevention. In this context, accurate information on the spatial patterns of risk of exposure to ticks is of prime importance for public health. The objective of our study was to provide a snapshot map of the risk of human infection with B. burgdorferi s. l. pathogens in a periurban forest at a high resolution, and to analyze the factors that contribute to variation in this risk. Field monitoring took place over three weeks in May 2011 in the suburban Sénart forest (3,200ha; southeast of Paris), which receives over 3 million people annually. We sampled ticks over the entire forest area (from 220 forest stands with a total area of 35,200m(2)) and quantified the density of questing nymphs (DON), the prevalence of infection among nymphs (NIP), and the density of infected nymphs (DIN), which is the most important predictor of the human risk of Lyme borreliosis. For each of these response variables, we explored the relative roles of weather (saturation deficit), hosts (abundance indices of ungulates and Tamias sibiricus, an introduced rodent species), vegetation and forest cover, superficial soil composition, and the distance to forest roads. In total, 19,546 questing nymphs were collected and the presence of B. burgdorferi s. l. was tested in 3,903 nymphs by qPCR. The mean DON was 5.6 nymphs per 10m(2) (standard deviation=10.4) with an average NIP of 10.1% (standard deviation=0.11). The highest DIN was 8.9 infected nymphs per 10m(2), with a mean of 0.59 (standard deviation=0.6). Our

  11. Utilization of serology for the diagnosis of suspected Lyme borreliosis in Denmark: survey of patients seen in general practice

    DEFF Research Database (Denmark)

    Dessau, Ram; Bangsborg, Jette Marie; Ejlertsen, Tove;

    2010-01-01

    Serological testing for Lyme borreliosis (LB) is frequently requested by general practitioners for patients with a wide variety of symptoms.......Serological testing for Lyme borreliosis (LB) is frequently requested by general practitioners for patients with a wide variety of symptoms....

  12. Genospecies diversity of Lyme disease spirochetes in rodent reservoirs.

    OpenAIRE

    Richter, D.; Endepols, S.; Ohlenbusch, A.; Eiffert, H.; Spielman, A.; Matuschka, F. R.

    1999-01-01

    To determine whether particular Borrelia burgdorferi s.l. genospecies associate solely with rodent reservoir hosts, we compared the genospecies prevalence in questing nymphal Ixodes ticks with that in xenodiagnostic ticks that had fed as larvae on rodents captured in the same site. No genospecies was more prevalent in rodent-fed ticks than in questing ticks. The three main spirochete genospecies, therefore, share common rodent hosts.

  13. Lyme arthritis. Spirochetes found in synovial microangiopathic lesions.

    OpenAIRE

    Johnston, Y. E.; Duray, P. H.; Steere, A. C.; Kashgarian, M.; Buza, J.; Malawista, S E; Askenase, P. W.

    1985-01-01

    In 17 patients with Lyme disease, synovial specimens, obtained by synovectomy or needle biopsy, showed nonspecific villous hypertrophy, synovial cell hyperplasia, prominent microvasculature, lymphoplasmacellular infiltration, and sometimes lymphoid follicles. The larger surgically obtained specimens also showed striking deposition of fibrin in synovial stroma and a form of endarteritis obliterans. In 2 patients, spirochetes were seen in and around blood vessels by the Dieterle silver stain. C...

  14. Interaction of the Lyme disease spirochete with its tick vector.

    Science.gov (United States)

    Caimano, Melissa J; Drecktrah, Dan; Kung, Faith; Samuels, D Scott

    2016-07-01

    Borrelia burgdorferi, the causative agent of Lyme disease (along with closely related genospecies), is in the deeply branching spirochete phylum. The bacterium is maintained in nature in an enzootic cycle that involves transmission from a tick vector to a vertebrate host and acquisition from a vertebrate host to a tick vector. During its arthropod sojourn, B. burgdorferi faces a variety of stresses, including nutrient deprivation. Here, we review some of the spirochetal factors that promote persistence, maintenance and dissemination of B. burgdorferi in the tick, and then focus on the utilization of available carbohydrates as well as the exquisite regulatory systems invoked to adapt to the austere environment between blood meals and to signal species transitions as the bacteria traverse their enzootic cycle. The spirochetes shift their source of carbon and energy from glucose in the vertebrate to glycerol in the tick. Regulation of survival under limiting nutrients requires the classic stringent response in which RelBbu controls the levels of the alarmones guanosine tetraphosphate and guanosine pentaphosphate (collectively termed (p)ppGpp), while regulation at the tick-vertebrate interface as well as regulation of protective responses to the blood meal require the two-component system Hk1/Rrp1 to activate production of the second messenger cyclic-dimeric-GMP (c-di-GMP). PMID:27147446

  15. Amplification of the flgE gene provides evidence for the existence of a Brazilian borreliosis

    Directory of Open Access Journals (Sweden)

    Elenice Mantovani

    2012-06-01

    Full Text Available INTRODUCTION: The symptoms of Brazilian borreliosis resemble the clinical manifestations of Lyme disease (LD. However, there are differences between the two in terms of epidemiological and laboratory findings. Primers usually employed to diagnose LD have failed to detect Borrelia strains in Brazil. OBJECTIVE: We aimed to identify the Brazilian Borrelia using a conserved gene that synthesizes the flagellar hook (flgE of Borrelia burgdorferi sensu lato. METHOD: Three patients presenting with erythema migrans and positive epidemiological histories were recruited for the study. Blood samples were collected, and the DNA was extracted by commercial kits. RESULTS: The gene flgE was amplified from DNA of all selected patients. Upon sequencing, these positive samples revealed 99% homology to B. burgdorferi flgE. CONCLUSION: These results support the existence of borreliosis in Brazil. However, it is unclear whether this borreliosis is caused by a genetically modified B. burgdorferi sensu stricto or by a new species of Borrelia spp.

  16. Enfermedad de Lyme (Borreliosis de Lyme en Costa Rica

    Directory of Open Access Journals (Sweden)

    Ricardo Boza-Cordero

    2011-01-01

    Full Text Available La enfermedad de Lyme o borreliosis de Lyme es una zoonosis transmitida por garrapatas del género Ixodes y producida por la espiroqueta Borrelia burgdorferi. Ha sido descrita principalmente en Norteamérica, Europa y Asia, y se caracteriza clínicamente por una presentación en tres etapas: inicial con eritema migrans que comienza alrededor de la picadura de la garrapata; infección diseminada con fiebre, ataque al estado general, artritis migratoria, linfadenopatías, alteraciones neurológicas y hepatitis; y la forma crónica, caracterizada por artritis, periostitis, encefalomielitis crónica y polirradiculopatía, entre otras manifestaciones. En Costa Rica se desconocen notificaciones de pacientes con esta patología, por lo que se presenta el caso de una mujer adulta que tras un viaje al Estado de La Florida en los Estados Unidos, presentó cuadro clínico y serológico compatible con la forma leve de la enfermedad de Lyme. Se discuten los hallazgos y se alerta sobre la posibilidad de diagnosticar esta zoonosis, dado el auge del turismo ecológico en estos días.

  17. Differential spirochetal infectivities to vector ticks of mice chronically infected by the agent of Lyme disease.

    OpenAIRE

    Shih, C M; L. P. LIU; Spielman, A.

    1995-01-01

    We determined whether the infectivity of the Lyme disease spirochete (Borrelia burgdorferi) to vector ticks varies with the duration of infection in laboratory mice. Thus, noninfected nymphal deer ticks were permitted to feed on two strains of early (2 months after infection) and late (8 months after infection) spirochete-infected mice. The attached ticks were removed from their hosts at specified time intervals and were thereafter examined for spirochetes by direct immunofluorescence microsc...

  18. Ocular Lyme borreliosis as a rare presentation of unilateral vision loss.

    Science.gov (United States)

    Patterson-Fortin, Jeffrey; Kohli, Anita; Suarez, Maria J; Miller, P Elliott

    2016-01-01

    Ocular Lyme borreliosis is a rare manifestation of Lyme disease. We describe a case of an 80-year-old woman who presented with a 1-month history of unilateral painless central vision loss. Based on a temporal artery biopsy, she was initially diagnosed with giant cell arteritis and treated with a 3-day course of high-dose intravenous steroids. A more detailed history uncovered multiple previous treatments for Lyme disease and residence in an endemic Lyme area. The patient was subsequently diagnosed with ocular Lyme borreliosis and treated with intravenous antibiotics. After 5 weeks of treatment, unilateral vision loss did not progress and optic disc oedema resolved. PMID:27113793

  19. Utilization of serology for the diagnosis of suspected Lyme borreliosis in Denmark: Survey of patients seen in general practice

    Directory of Open Access Journals (Sweden)

    Skarphedinsson Sigurdur

    2010-11-01

    Full Text Available Abstract Background Serological testing for Lyme borreliosis (LB is frequently requested by general practitioners for patients with a wide variety of symptoms. Methods A survey was performed in order to characterize test utilization and clinical features of patients investigated for serum antibodies to Borrelia burgdorferi sensu lato. During one calendar year a questionnaire was sent to the general practitioners who had ordered LB serology from patients in three Danish counties (population 1.5 million inhabitants. Testing was done with a commercial ELISA assay with purified flagella antigen from a Danish strain of B. afzelii. Results A total of 4,664 patients were tested. The IgM and IgG seropositivity rates were 9.2% and 3.3%, respectively. Questionnaires from 2,643 (57% patients were available for analysis. Erythema migrans (EM was suspected in 38% of patients, Lyme arthritis/disseminated disease in 23% and early neuroborreliosis in 13%. Age 0-15 years and suspected EM were significant predictors of IgM seropositivity, whereas suspected acrodermatitis was a predictor of IgG seropositivity. LB was suspected in 646 patients with arthritis, but only 2.3% were IgG seropositive. This is comparable to the level of seropositivity in the background population indicating that Lyme arthritis is a rare entity in Denmark, and the low pretest probability should alert general practitioners to the possibility of false positive LB serology. Significant predictors for treating the patient were a reported tick bite and suspected EM. Conclusions A detailed description of the utilization of serology for Lyme borreliosis with rates of seropositivity according to clinical symptoms is presented. Low rates of seropositivity in certain patient groups indicate a low pretest probability and there is a notable risk of false positive results. 38% of all patients tested were suspected of EM, although this is not a recommended indication due to a low sensitivity of

  20. Relationships of a Novel Lyme Disease Spirochete, Borrelia spielmani sp. nov., with Its Hosts in Central Europe

    OpenAIRE

    Richter, Dania; Schlee, Daniela B.; Allgöwer, Rainer; Matuschka, Franz-Rainer

    2004-01-01

    To determine whether the pathogenic variant of Lyme disease spirochetes, isolate A14S, is perpetuated in a particular reservoir-vector relationship, we screened vector ticks in various Central European sites for a related spirochete and determined its host association. A14S-like spirochetes infect numerous questing ticks in the Petite Camargue Alsacienne (PC). They frequently infect dormice, but no mice or voles. Garden dormice appear to be better reservoir hosts for A14S-like spirochetes tha...

  1. Allelic Variation of the Lyme Disease Spirochete Adhesin DbpA Influences Spirochetal Binding to Decorin, Dermatan Sulfate, and Mammalian Cells▿

    OpenAIRE

    Benoit, Vivian M.; Fischer, Joshua R.; Lin, Yi-Pin; Parveen, Nikhat; Leong, John M.

    2011-01-01

    After transmission by an infected tick, the Lyme disease spirochete, Borrelia burgdorferi sensu lato, colonizes the mammalian skin and may disseminate systemically. The three major species of Lyme disease spirochete—B. burgdorferi sensu stricto, B. garinii, and B. afzelii—are associated with different chronic disease manifestations. Colonization is likely promoted by the ability to bind to target tissues, and Lyme disease spirochetes utilize multiple adhesive molecules to interact with divers...

  2. C6 Peptide-Based Multiplex Phosphorescence Analysis (PHOSPHAN for Serologic Confirmation of Lyme Borreliosis.

    Directory of Open Access Journals (Sweden)

    Vera G Pomelova

    Full Text Available A single-tier immunoassay using the C6 peptide of VlsE (C6 from Borrelia burgdorferi sensu stricto (Bb has been proposed as a potential alternative to conventional two-tier testing for the serologic diagnosis of Lyme disease in the United States and Europe.To evaluate the performance of C6 peptide based multiplex Phosphorescence Analysis (PHOSPHAN for the serologic confirmation of Lyme borreliosis (LB in Russian patients.Serum samples (n = 351 were collected from 146 patients with erythema migrans (EM; samples from 131 of these patients were taken several times prior to treatment and at different stages of recovery. The control group consisted of 197 healthy blood donors and 31 patients with other diseases, all from the same highly endemic region of Russia. All samples were analyzed by PHOSPHAN for IgM and IgG to Bb C6, recombinant OspC and VlsE proteins, and C6 peptides from B. garinii and B. afzelii.IgM and IgG to Bb C6 were identified in 43 and 95 out of 131 patients (32.8 and 72.5%, respectively; seroconversion of IgM antibodies was observed in about half of the patients (51.2%, and of IgG antibodies, in almost all of them (88.4%. Additional detection of OspC-IgM and VlsE-IgM or IgG to C6 from B. garinii or B. afzelii did not contribute significantly to the overall sensitivity of the multiplex immunoassay.The multiplex phosphorescence immunoassay is a promising method for simultaneously revealing the spectrum of antibodies to several Borrelia antigens. Detection of IgM and IgG to Bb C6 in the sera of EM patients provides effective serologic confirmation of LB and, with high probability, indicates an active infection process.

  3. Emerging vector-borne diseases and environmental change: The rise of Lyme borreliosis in Western-Europe

    OpenAIRE

    Huitema, Tim

    2013-01-01

    SUMMARY During the last decade several infectious diseases started to emerge in Western-Europe. At the same time numerous environmental factors were changing. One of the diseases that apparently emerged is Lyme borreliosis (LB). This thesis aims to incre

  4. Emerging vector-borne diseases and environmental change : The rise of Lyme borreliosis in Western-Europe

    NARCIS (Netherlands)

    Huitema, Tim

    2013-01-01

    SUMMARY During the last decade several infectious diseases started to emerge in Western-Europe. At the same time numerous environmental factors were changing. One of the diseases that apparently emerged is Lyme borreliosis (LB). This thesis aims to incre

  5. Periplasmal Physics: The Rotational Dynamics of Spirochetal Flagella

    Science.gov (United States)

    Huber, Greg

    2012-02-01

    Spirochetes are distinguished by the location of their flagella, which reside within the periplasm: the tiny space between the bacterial cell wall and the outer membrane. In Borrelia burgdorferi/ (the causative agent of Lyme Disease), rotation of the flagella leads to cellular undulations that drive swimming. Exactly how these shape changes arise due to the forces and torques acting between the flagella and the cell body is unknown. By applying low-Reynolds number hydrodynamic theory to the motion of an elastic flagellum rotating in the periplasm, we show that the flagella are most likely separated from the bacterial cell wall by a lubricating layer of fluid. We obtain analytical solutions for the force and torque on the rotating flagellum through lubrication analysis, as well as through scaling analysis, and find results are in close agreement numerical simulations. (Joint work with J. Yang and C.W. Wolgemuth.)

  6. Genetic structure of marine Borrelia garinii and population admixture with the terrestrial cycle of Lyme borreliosis

    OpenAIRE

    Gomez-Diaz, E.; Boulinier, T.; Sertour, N.; Cornet, M.; Ferquel, E.; McCoy, Karen

    2011-01-01

    Despite the importance of population structure for the epidemiology of pathogenic bacteria, the spatial and ecological heterogeneity of these populations is often poorly characterized. Here, we investigated the genetic diversity and population structure of the Lyme borreliosis (LB) spirochaete Borrelia garinii in its marine cycle involving colonial seabirds and different host races of the seabird tick Ixodes uriae. Multilocus sequence analyses (MLSA) on eight chromosomal and two plasmid loci ...

  7. Introduced Siberian Chipmunks (Tamias sibiricus barberi) Contribute More to Lyme Borreliosis Risk than Native Reservoir Rodents

    OpenAIRE

    Maud Marsot; Jean-Louis Chapuis; Patrick Gasqui; Anne Dozières; Sébastien Masséglia; Benoit Pisanu; Elisabeth Ferquel; Gwenaël Vourc'h

    2013-01-01

    The variation of the composition in species of host communities can modify the risk of disease transmission. In particular, the introduction of a new host species can increase health threats by adding a new reservoir and/or by amplifying the circulation of either exotic or native pathogens. Lyme borreliosis is a multi-host vector-borne disease caused by bacteria belonging to the Borrelia burgdorferi sensu lato complex. It is transmitted by the bite of hard ticks, especially Ixodes ricinus in ...

  8. Purification, crystallization and preliminary X-ray analysis of TP0435 (Tp17) from the syphilis spirochete Treponema pallidum

    International Nuclear Information System (INIS)

    The soluble portion of TP0435, a putative periplasmic lipoprotein from the syphilis spirochete T. pallidum, has been purified and crystallized in a rhombohedral space group. A complete native data set has been collected to 2.4 Å resolution. Syphilis, caused by the bacterial spirochete Treponema pallidum, remains a prominent sexually transmitted infection worldwide. Despite sequencing of the genome of this obligate human pathogen 15 years ago, the functions of a large number of the gene products of T. pallidum are still unknown, particularly with respect to those of the organism’s periplasmic lipoproteins. To better understand their functions, a structural biology approach has been pursued. To this end, the soluble portion of the T. pallidum TP0435 lipoprotein (also known as Tp17) was cloned, hyper-expressed in Escherichia coli and purified to apparent homogeneity. The protein crystals obtained from this preparation diffracted to 2.4 Å resolution and had the symmetry of space group R3. In the hexagonal setting, the unit-cell parameters were a = b = 85.7, c = 85.4 Å

  9. Interactions of phagocytes with the Lyme disease spirochete: role of the Fc receptor

    Energy Technology Data Exchange (ETDEWEB)

    Benach, J.L.; Fleit, H.B.; Habicht, G.S.; Coleman, J.L.; Bosler, E.M.; Lane, B.P.

    1984-10-01

    The phagocytic capacity of murine and human mononuclear and polymorphonuclear phagocytes (including peripheral blood monocytes and neutrophils), rabbit and murine peritoneal exudate cells, and the murine macrophage cell line P388D1 against the Lyme disease spirochete was studied. All of these cells were capable of phagocytosing the spirochete; phagocytosis was measured by the uptake of radiolabeled spirochetes, the appearance of immunofluorescent bodies in phagocytic cells, and electron microscopy. Both opsonized and nonopsonized organisms were phagocytosed. The uptake of opsonized organisms by neutrophils was blocked by a monoclonal antibody specific for the Fc receptor and by immune complexes; these findings suggested that most phagocytosis is mediated by the Fc receptor. Similarly, the uptake of opsonized organisms by human monocytes was inhibited by human monomeric IgG1 and by immune complexes. These results illustrate the role of immune phagocytosis of spirochetes in host defense against Lyme disease.

  10. Interactions of phagocytes with the Lyme disease spirochete: role of the Fc receptor

    International Nuclear Information System (INIS)

    The phagocytic capacity of murine and human mononuclear and polymorphonuclear phagocytes (including peripheral blood monocytes and neutrophils), rabbit and murine peritoneal exudate cells, and the murine macrophage cell line P388D1 against the Lyme disease spirochete was studied. All of these cells were capable of phagocytosing the spirochete; phagocytosis was measured by the uptake of radiolabeled spirochetes, the appearance of immunofluorescent bodies in phagocytic cells, and electron microscopy. Both opsonized and nonopsonized organisms were phagocytosed. The uptake of opsonized organisms by neutrophils was blocked by a monoclonal antibody specific for the Fc receptor and by immune complexes; these findings suggested that most phagocytosis is mediated by the Fc receptor. Similarly, the uptake of opsonized organisms by human monocytes was inhibited by human monomeric IgG1 and by immune complexes. These results illustrate the role of immune phagocytosis of spirochetes in host defense against Lyme disease

  11. Comparison of the genome of the oral pathogen Treponema denticola with other spirochete genomes

    OpenAIRE

    Seshadri, Rekha; Myers, Garry S A; Tettelin, Hervé; Eisen, Jonathan A.; Heidelberg, John F.; Robert J Dodson; Davidsen, Tanja M.; DeBoy, Robert T; Derrick E Fouts; Haft, Dan H.; Selengut, Jeremy; Ren, Qinghu; Brinkac, Lauren M.; Madupu, Ramana; Kolonay, Jamie

    2004-01-01

    We present the complete 2,843,201-bp genome sequence of Treponema denticola (ATCC 35405) an oral spirochete associated with periodontal disease. Analysis of the T. denticola genome reveals factors mediating coaggregation, cell signaling, stress protection, and other competitive and cooperative measures, consistent with its pathogenic nature and lifestyle within the mixed-species environment of subgingival dental plaque. Comparisons with previously sequenced spirochete genomes revealed specifi...

  12. Isolation of live Borrelia burgdorferi sensu lato spirochaetes from patients with undefined disorders and symptoms not typical for Lyme borreliosis.

    Science.gov (United States)

    Rudenko, N; Golovchenko, M; Vancova, M; Clark, K; Grubhoffer, L; Oliver, J H

    2016-03-01

    Lyme borreliosis is a multisystem disorder with a diverse spectrum of clinical manifestations, caused by spirochaetes of the Borrelia burgdorferi sensu lato complex. It is an infectious disease that can be successfully cured by antibiotic therapy in the early stages; however, the possibility of the appearance of persistent signs and symptoms of disease following antibiotic treatment is recognized. It is known that Lyme borreliosis mimics multiple diseases that were never proven to have a spirochaete aetiology. Using complete modified Kelly-Pettenkofer medium we succeeded in cultivating live B. burgdorferi sensu lato spirochaetes from samples taken from people who suffered from undefined disorders, had symptoms not typical for Lyme borreliosis, but who had undergone antibiotic treatment due to a suspicion of having Lyme disease even though they were seronegative. We report the first recovery of live B. burgdorferi sensu stricto from residents of southeastern USA and the first successful cultivation of live Borrelia bissettii-like strain from residents of North America. Our results support the fact that B. bissettii is responsible for human Lyme borreliosis worldwide along with B. burgdorferi s.s. The involvement of new spirochaete species in Lyme borreliosis changes the understanding and recognition of clinical manifestations of this disease. PMID:26673735

  13. Seropositivity of Lyme borreliosis and associated risk factors: a population-based study in Children and Adolescents in Germany (KiGGS.

    Directory of Open Access Journals (Sweden)

    Manuel Dehnert

    Full Text Available BACKGROUND: Lyme borreliosis (LB caused by spirochetes of the Borrelia burgdorferi sensu lato complex is the most common tick-borne disease in the northern hemisphere. Data on the distribution and on risk factors in Germany are sketchy. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples of a nationwide population-based cross-sectional study from 2003-2006 in children and adolescents aged 1 to 17 years in Germany (KiGGS were analysed (n = 12,614 to assess the seroprevalence of anti-Borrelia antibodies. Data from standardized interviews were used to assess potential risk factors. First, sera were screened for anti-Borrelia antibodies by ELISA. The overall prevalence was 4.8% (95% confidence interval (CI 4.3-5.4%. Positive and borderline ELISA test results were confirmed by a line blot revealing a combined prevalence of 4.0% (95% CI 3.6-4.5%. Seroprevalence of ELISA was significantly higher in males (odds ratio (OR = 1.37; CI 1.15-1.63 and in the southern part of Germany (OR = 1.41; CI 1.09-1.83, but significantly lower in children and adolescents with migration background (OR = 0.33; CI 0.24-0.44. Study participants from households with cats had a higher chance of seropositivity (OR = 6.7; CI 5.6-8.0. In a multivariable model the odds of seropositivity increases by 11% for every year of age for boys and 6% for girls. CONCLUSIONS/SIGNIFICANCE: This survey is the first nationwide, representative seroprevalence survey of LB in children and young adolescents. The study shows that infections with Borrelia burgdorferi are endemic in all parts of Germany despite regional differences. Even at a young age children are exposed to tick bites including seropositivity. Encouraging a thorough check for ticks and promptly removal of ticks are the key public health strategies to reduce the risk of LB and other tick-borne diseases in children and adolescents. Further epidemiological studies are warranted to better understand the burden of disease related to LB.

  14. Lyme arthritis in Southern Norway - an endemic area for Lyme Borreliosis

    OpenAIRE

    Haugeberg, Glenn; Hansen, Inger Johanne W.; Skarpaas, Tone; Noraas, Sølvi; Kjelland, Vivian

    2014-01-01

    Background: Despite Southern Norway is an endemic area for Lyme borreliosis there is a lack of data on Lyme arthritis (LA). In the literature controversies exist if acute LA can develop into chronic arthritis. Our objective was to identify and characterize patients with LA in Southern Norway and explore disease course after antibiotic treatment.Methods: Patients aged 20 years or older with arthritis and a positive serology for Borrelia burgdorferi infection (IgG and/or IgM) suspected of havin...

  15. Direct measurement of helical cell motion of the spirochete leptospira.

    Science.gov (United States)

    Nakamura, Shuichi; Leshansky, Alexander; Magariyama, Yukio; Namba, Keiichi; Kudo, Seishi

    2014-01-01

    Leptospira are spirochete bacteria distinguished by a short-pitch coiled body and intracellular flagella. Leptospira cells swim in liquid with an asymmetric morphology of the cell body; the anterior end has a long-pitch spiral shape (S-end) and the posterior end is hook-shaped (H-end). Although the S-end and the coiled cell body called the protoplasmic cylinder are thought to be responsible for propulsion together, most observations on the motion mechanism have remained qualitative. In this study, we analyzed the swimming speed and rotation rate of the S-end, protoplasmic cylinder, and H-end of individual Leptospira cells by one-sided dark-field microscopy. At various viscosities of media containing different concentrations of Ficoll, the rotation rate of the S-end and protoplasmic cylinder showed a clear correlation with the swimming speed, suggesting that these two helical parts play a central role in the motion of Leptospira. In contrast, the H-end rotation rate was unstable and showed much less correlation with the swimming speed. Forces produced by the rotation of the S-end and protoplasmic cylinder showed that these two helical parts contribute to propulsion at nearly equal magnitude. Torque generated by each part, also obtained from experimental motion parameters, indicated that the flagellar motor can generate torque >4000 pN nm, twice as large as that of Escherichia coli. Furthermore, the S-end torque was found to show a markedly larger fluctuation than the protoplasmic cylinder torque, suggesting that the unstable H-end rotation might be mechanically related to changes in the S-end rotation rate for torque balance of the entire cell. Variations in torque at the anterior and posterior ends of the Leptospira cell body could be transmitted from one end to the other through the cell body to coordinate the morphological transformations of the two ends for a rapid change in the swimming direction. PMID:24411236

  16. Beta-Amyloid Deposition and Alzheimer's Type Changes Induced by Borrelia Spirochetes

    Energy Technology Data Exchange (ETDEWEB)

    Miklossy,J.; Kis, A.; Radenovic, A.; Miller, L.; Forro, L.; Martins, R.; Reiss, K.; Darbinian, N.; Darekar, P.; et al.

    2006-01-01

    The pathological hallmarks of Alzheimer's disease (AD) consist of {beta}-amyloid plaques and neurofibrillary tangles in affected brain areas. The processes, which drive this host reaction are unknown. To determine whether an analogous host reaction to that occurring in AD could be induced by infectious agents, we exposed mammalian glial and neuronal cells in vitro to Borrelia burgdorferi spirochetes and to the inflammatory bacterial lipopolysaccharide (LPS). Morphological changes analogous to the amyloid deposits of AD brain were observed following 2-8 weeks of exposure to the spirochetes. Increased levels of {beta}-amyloid presursor protein (A{beta}PP) and hyperphosphorylated tau were also detected by Western blots of extracts of cultured cells that had been treated with spirochetes or LPS. These observations indicate that, by exposure to bacteria or to their toxic products, host responses similar in nature to those observed in AD may be induced.

  17. Viscous Dynamics of Lyme Disease and Syphilis Spirochetes Reveal Flagellar Torque and Drag

    Science.gov (United States)

    Harman, Michael; Vig, Dhruv K.; Radolf, Justin D.; Wolgemuth, Charles W.

    2013-01-01

    The spirochetes that cause Lyme disease (Borrelia burgdorferi) and syphilis (Treponema pallidum) swim through viscous fluids, such as blood and interstitial fluid, by undulating their bodies as traveling, planar waves. These undulations are driven by rotation of the flagella within the periplasmic space, the narrow (∼20–40 nm in width) compartment between the inner and outer membranes. We show here that the swimming speeds of B. burgdorferi and T. pallidum decrease with increases in viscosity of the external aqueous milieu, even though the flagella are entirely intracellular. We then use mathematical modeling to show that the measured changes in speed are consistent with the exertion of constant torque by the spirochetal flagellar motors. Comparison of simulations, experiments, and a simple model for power dissipation allows us to estimate the torque and resistive drag that act on the flagella of these major spirochetal pathogens. PMID:24268139

  18. Purification, crystallization and preliminary X-ray analysis of TP0435 (Tp17) from the syphilis spirochete Treponema pallidum

    Science.gov (United States)

    Brautigam, Chad A.; Deka, Ranjit K.; Norgard, Michael V.

    2013-01-01

    Syphilis, caused by the bacterial spirochete Treponema pallidum, remains a prominent sexually transmitted infection worldwide. Despite sequencing of the genome of this obligate human pathogen 15 years ago, the functions of a large number of the gene products of T. pallidum are still unknown, particularly with respect to those of the organism’s periplasmic lipoproteins. To better understand their functions, a structural biology approach has been pursued. To this end, the soluble portion of the T. pallidum TP0435 lipoprotein (also known as Tp17) was cloned, hyper-expressed in Escherichia coli and purified to apparent homogeneity. The protein crystals obtained from this preparation diffracted to 2.4 Å resolution and had the symmetry of space group R3. In the hexagonal setting, the unit-cell parameters were a = b = 85.7, c = 85.4 Å. PMID:23545658

  19. Rapid Typing of Borrelia burgdorferi Sensu Lato Species in Specimens from Patients with Different Manifestations of Lyme Borreliosis

    OpenAIRE

    Lünemann, Jan D.; Zarmas, Silvia; Priem, Susanne; Franz, Juliane; Zschenderlein, Rolf; Aberer, Elisabeth; Klein, Rolf; Schouls, Leon; Burmester, Gerd R.; Krause, Andreas

    2001-01-01

    To further investigate the pathogenic potential of different Borrelia burgdorferi genospecies, specimens from 27 patients with different manifestations of Lyme borreliosis were analyzed by PCR and reverse line blotting (RLB). In samples from Lyme arthritis patients, B. burgdorferi sensu stricto was predominantly identified, while in patients with neuroborreliosis or acrodermatitis, Borrelia garinii and Borrelia afzelii, respectively, were exclusively detected. The results demonstrate that PCR...

  20. Simultaneous use of serum IgG and IgM for risk scoring of suspected early Lyme borreliosis

    DEFF Research Database (Denmark)

    Dessau, Ram B; Ejlertsen, Tove; Hilden, Jørgen

    2010-01-01

    The laboratory diagnosis of early disseminated Lyme borreliosis (LB) rests on IgM and IgG antibodies in serum. The purpose of this study was to refine the statistical interpretation of IgM and IgG by combining the diagnostic evidence provided by the two immunoglobulins and exploiting the whole...

  1. Genetic structure of marine Borrelia garinii and population admixture with the terrestrial cycle of Lyme borreliosis.

    Science.gov (United States)

    Gómez-Díaz, Elena; Boulinier, Thierry; Sertour, Natacha; Cornet, Muriel; Ferquel, Elisabeth; McCoy, Karen D

    2011-09-01

    Despite the importance of population structure for the epidemiology of pathogenic bacteria, the spatial and ecological heterogeneity of these populations is often poorly characterized. Here, we investigated the genetic diversity and population structure of the Lyme borreliosis (LB) spirochaete Borrelia garinii in its marine cycle involving colonial seabirds and different host races of the seabird tick Ixodes uriae. Multilocus sequence analyses (MLSA) on eight chromosomal and two plasmid loci (ospA and ospC) indicate that B. garinii circulating in the marine system is highly diverse. Microevolution in marine B. garinii seems to be mainly clonal, but recombination and selection do occur. Sequence types were not evenly distributed among geographic regions, with substantial population subdivision between Atlantic and Pacific Ocean basins. However, no geographic structuring was evident within regions. Results of selection analyses and phylogenetic discordance between chromosomal and plasmid loci indicate adaptive evolution is likely occurring in this system, but no pattern of host or vector-associated divergence was found. Recombination analyses showed evidence for population admixture between terrestrial and marine strains, suggesting that LB spirochaetes are exchanged between these enzootic cycles. Importantly, our results highlight the need to explicitly consider the marine system for a complete understanding of the evolutionary ecology and global epidemiology of Lyme borreliosis. PMID:21651685

  2. Zoonotic occupational diseases in forestry workers – Lyme borreliosis, tularemia and leptospirosis in Europe

    Directory of Open Access Journals (Sweden)

    Stéphanie Richard

    2015-02-01

    Full Text Available [b]Introduction[/b]. Forestry workers and other people who come into close contact with wild animals, such as hunters, natural science researchers, game managers or mushroom/berry pickers, are at risk of contracting bacterial, parasitological or viral zoonotic diseases. Synthetic data on the incidence and prevalence of zoonotic diseases in both animals and humans in European forests do not exist. It is therefore difficult to promote appropriate preventive measures among workers or people who come into direct or indirect contact with forest animals. [b]Objectives.[/b] The objectives of this review are to synthesise existing knowledge on the prevalence of the three predominant bacterial zoonotic diseases in Europe, i.e. Lyme borreliosis, tularemia and leptospirosis, in order to draw up recommendations for occupational or public health. [b]Methods[/b]. 88 papers published between 1995–2013 (33 on Lyme borreliosis, 30 on tularemia and 25 on leptospirosis were analyzed. [b]Conclusions[/b]. The prevalences of these three zoonotic diseases are not negligible and information targeting the public is needed. Moreover, the results highlight the lack of standardised surveys among different European countries. It was also noted that epidemiological data on leptospirosis are very scarce

  3. Papillomatous Digital Dermatitis Spirochetes Suppress the Bovine Macrophage Innate Immune Response

    Science.gov (United States)

    Papillomatous digital dermatitis (PDD) is a polymicrobial infection in soft tissue adjacent to the hoof and is the leading cause of lameness in dairy cattle. Treponema phagedenis-like (TPL) spirochetes are a constant feature of PDD lesions and are localized deep in infected tissue. Host-cell respon...

  4. Remotely sensed vegetation moisture as explanatory variable of Lyme borreliosis incidence

    Science.gov (United States)

    Barrios, J. M.; Verstraeten, W. W.; Maes, P.; Clement, J.; Aerts, J. M.; Farifteh, J.; Lagrou, K.; Van Ranst, M.; Coppin, P.

    2012-08-01

    The strong correlation between environmental conditions and abundance and spatial spread of the tick Ixodes ricinus is widely documented. I. ricinus is in Europe the main vector of the bacterium Borrelia burgdorferi, the pathogen causing Lyme borreliosis (LB). Humidity in vegetated systems is a major factor in tick ecology and its effects might translate into disease incidence in humans. Time series of two remotely sensed indices with sensitivity to vegetation greenness and moisture were tested as explanatory variables of LB incidence. Wavelet-based multiresolution analysis allowed the examination of these signals at different temporal scales in study sites in Belgium, where increases in LB incidence were reported in recent years. The analysis showed the potential of the tested indices for disease monitoring, the usefulness of analyzing the signal in different time frames and the importance of local characteristics of the study area for the selection of the vegetation index.

  5. Helical Conformation of Treponema pallidum (Nichols Strain), Treponema paraluis-cuniculi, Treponema denticola, Borrelia turicatae, and Unidentified Oral Spirochetes

    OpenAIRE

    Stepan, Daniel E.; Johnson, Russell C.

    1981-01-01

    Borrelia turicatae (mouse virulent) and Treponema denticola, a small oral treponeme, formed right-handed helices as determined by scanning electron microscopy. Treponema pallidum (Nichols strain), Treponema paraluis-cuniculi, and two unidentified oral spirochetes displayed left-handed helices.

  6. Range of atrioventricular conduction disturbances in Lyme borreliosis: a report of four cases and review of other published reports.

    OpenAIRE

    van der Linde, M R; Crijns, H. J.; de Koning, J; Hoogkamp-Korstanje, J A; de Graaf, J J; Piers, D A; van der Galiën, A; Lie, K I

    1990-01-01

    Four patients with Lyme borreliosis had atrioventricular conduction disturbances. All four were positive for specific antibodies against Borrelia burgdorferi measured by indirect immunofluorescence tests. Biopsy specimens, which were obtained in three patients, showed band-like infiltrates of plasma cells and lymphocytes in the endocardium. There was diffuse infiltration of the interstitium of the myocardium by lymphocytes, plasma cells, and macrophages. In two patients single fibre necrosis ...

  7. Validity of Interpretation Criteria for Standardized Western Blots (Immunoblots) for Serodiagnosis of Lyme Borreliosis Based on Sera Collected throughout Europe

    OpenAIRE

    Hauser, Ulrike; Lehnert, Gisela; Wilske, Bettina

    1999-01-01

    Western blotting (WB; immunoblotting) is a widely used tool for the serodiagnosis of Lyme borreliosis (LB), but so far, no generally accepted criteria for performance and interpretation have been established in Europe. The current study was preceeded by a detailed analysis of WB with whole-cell lysates of three species of Borrelia burgdorferi sensu lato (U. Hauser, G. Lehnert, R. Lobentanzer, and B. Wilske, J. Clin. Microbiol. 35:1433–1444, 1997). In that study, interpretation criteria for a ...

  8. The Binary Protein Interactome of Treponema pallidum – The Syphilis Spirochete

    OpenAIRE

    Titz, Björn; Rajagopala, Seesandra V.; Goll, Johannes; Häuser, Roman; McKevitt, Matthew T; Palzkill, Timothy; Uetz, Peter

    2008-01-01

    Protein interaction networks shed light on the global organization of proteomes but can also place individual proteins into a functional context. If we know the function of bacterial proteins we will be able to understand how these species have adapted to diverse environments including many extreme habitats. Here we present the protein interaction network for the syphilis spirochete Treponema pallidum which encodes 1,039 proteins, 726 (or 70%) of which interact via 3,649 interactions as revea...

  9. Strain Variation in Glycosaminoglycan Recognition Influences Cell-Type-Specific Binding by Lyme Disease Spirochetes

    OpenAIRE

    Parveen, Nikhat; Robbins, Douglas; Leong, John M.

    1999-01-01

    Lyme disease, a chronic multisystemic disorder that can affect the skin, heart, joints, and nervous system is caused by Borrelia burgdorferi sensu lato. Lyme disease spirochetes were previously shown to bind glycosaminoglycans (GAGs). In the current study, the GAG-binding properties of eight Lyme disease strains were determined. Binding by two high-passage HB19 derivatives to Vero cells could not be inhibited by enzymatic removal of GAGs or by the addition of exogenous GAG. The other six stra...

  10. The Riboswitch Regulates a Thiamine Pyrophosphate ABC Transporter of the Oral Spirochete Treponema denticola ▿ †

    OpenAIRE

    Bian, Jiang; Shen, Hongwu; Tu, Youbin; Yu, Aiming; Li, Chunhao

    2011-01-01

    Thiamine pyrophosphate (TPP), a biologically active form of thiamine (vitamin B1), is an essential cofactor in all living systems. Microorganisms either synthesize TPP via de novo biosynthesis pathways or uptake exogenous thiamine from the environment via specific transporters. The oral spirochete Treponema denticola is an important pathogen that is associated with human periodontal diseases. It lacks a de novo TPP biosynthesis pathway and needs exogenous TPP for growth, suggesting that it ma...

  11. Microscopic agglutination and polyacrylamide gel electrophoresis analyses of oral anaerobic spirochetes.

    OpenAIRE

    Tall, B D; Nauman, R K

    1986-01-01

    Microscopic agglutination (MA) analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine strain and species similarities and dissimilarities among three species of oral anaerobic spirochetes, Treponema denticola, Treponema pectinovorum, and Treponema vincentii. The MA analysis revealed a diversity of serologic reactivity or sharing of common antigens within each species. However, there was no cross-reactivity or sharing of common antigens among t...

  12. Cryo-electron tomography elucidates the molecular architecture of Treponema pallidum, the syphilis spirochete.

    Science.gov (United States)

    Izard, Jacques; Renken, Christian; Hsieh, Chyong-Ere; Desrosiers, Daniel C; Dunham-Ems, Star; La Vake, Carson; Gebhardt, Linda L; Limberger, Ronald J; Cox, David L; Marko, Michael; Radolf, Justin D

    2009-12-01

    Cryo-electron tomography (CET) was used to examine the native cellular organization of Treponema pallidum, the syphilis spirochete. T. pallidum cells appeared to form flat waves, did not contain an outer coat and, except for bulges over the basal bodies and widening in the vicinity of flagellar filaments, displayed a uniform periplasmic space. Although the outer membrane (OM) generally was smooth in contour, OM extrusions and blebs frequently were observed, highlighting the structure's fluidity and lack of attachment to underlying periplasmic constituents. Cytoplasmic filaments converged from their attachment points opposite the basal bodies to form arrays that ran roughly parallel to the flagellar filaments along the inner surface of the cytoplasmic membrane (CM). Motile treponemes stably attached to rabbit epithelial cells predominantly via their tips. CET revealed that T. pallidum cell ends have a complex morphology and assume at least four distinct morphotypes. Images of dividing treponemes and organisms shedding cell envelope-derived blebs provided evidence for the spirochete's complex membrane biology. In the regions without flagellar filaments, peptidoglycan (PG) was visualized as a thin layer that divided the periplasmic space into zones of higher and lower electron densities adjacent to the CM and OM, respectively. Flagellar filaments were observed overlying the PG layer, while image modeling placed the PG-basal body contact site in the vicinity of the stator-P-collar junction. Bioinformatics and homology modeling indicated that the MotB proteins of T. pallidum, Treponema denticola, and Borrelia burgdorferi have membrane topologies and PG binding sites highly similar to those of their well-characterized Escherichia coli and Helicobacter pylori orthologs. Collectively, our results help to clarify fundamental differences in cell envelope ultrastructure between spirochetes and gram-negative bacteria. They also confirm that PG stabilizes the flagellar motor

  13. Filament formation associated with spirochetal infection: a comparative approach to Morgellons disease

    OpenAIRE

    Middelveen MJ; Stricker RB

    2011-01-01

    Marianne J Middelveen, Raphael B StrickerInternational Lyme and Associated Diseases Society, Bethesda, MD, USAAbstract: Bovine digital dermatitis is an emerging infectious disease that causes lameness, decreased milk production, and weight loss in livestock. Proliferative stages of bovine digital dermatitis demonstrate keratin filament formation in skin above the hooves in affected animals. The multifactorial etiology of digital dermatitis is not well understood, but spirochetes and other coi...

  14. Novel spirochetes isolated from mosquitoes and black flies in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Šikutová, Silvie; Halouzka, Jiří; Mendel, Jan; Knoz, J.; Rudolf, Ivo

    2010-01-01

    Roč. 35, č. 1 (2010), s. 50-55. ISSN 1081-1710 R&D Projects: GA ČR GA206/00/1234; GA ČR GA206/03/0726 Institutional research plan: CEZ:AV0Z60930519 Keywords : Spirochetes * mosquitoes * black flies * tabanid flies * Czech Republic Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.256, year: 2010

  15. Isolation of Spirochetes of Genus Treponema from Pigs with Ear Necrosis

    OpenAIRE

    Pringle, Märit; Backhans, Annette; Otman, Faruk; Sjölund, Marie; Fellström, Claes

    2009-01-01

    Abstract Various ear lesions, often caused by ear biting, are common in pigs. Some herds have a high frequency of ear necrosis, a syndrome characterized by necrotic lesions along the rim of the pinna, often bilateral and sometimes resulting in loss of the entire ear. In samples from such lesions spirochetes have been observed microscopically but never isolated or identified. In this study two herds with periodic outbreaks of ear necrosis among weaners were investigated. Samples wer...

  16. Incidence and hospitalisation rates of Lyme borreliosis, France, 2004 to 2012.

    Science.gov (United States)

    Vandenesch, A; Turbelin, C; Couturier, E; Arena, C; Jaulhac, B; Ferquel, E; Choumet, V; Saugeon, C; Coffinieres, E; Blanchon, T; Vaillant, V; Hanslik, T

    2014-08-28

    Lyme borreliosis (LB) has become a major concern recently, as trends in several epidemiological studies indicate that there has been an increase in this disease in Europe and America over the last decade. This work provides estimates of LB incidence and hospitalisation rates in France. LB data was obtained from the Sentinelles general practitioner surveillance network (2009–2012) and from the Programme de Médicalisation des Systèmes d’Information (PMSI) data processing centre for hospital discharges (2004–09). The yearly LB incidence rate averaged 42 per 100,000 inhabitants (95% confidence interval (CI): 37–48), ranging from 0 to 184 per 100,000 depending on the region. The annual hospitalisation rate due to LB averaged 1.55 per 100,000 inhabitants (95% CI: 1.42–1.70). Both rates peaked during the summer and fall and had a bimodal age distribution (5–10 years and 50–70 years). Healthcare providers should continue to invest attention to prompt recognition and early therapy for LB, whereas public health strategies should keep promoting use of repellent, daily checks for ticks and their prompt removal. PMID:25188613

  17. A novel lymphocyte transformation test (LTT-MELISA) for Lyme borreliosis.

    Science.gov (United States)

    Valentine-Thon, Elizabeth; Ilsemann, Karsten; Sandkamp, Martin

    2007-01-01

    Diagnosis of active Lyme borreliosis (LB) remains a challenge in clinically ambiguous, serologically indeterminant, and polymerase chain reaction-negative patients. Lymphocyte transformation tests (LTTs) have been applied to detect specific cellular immune reactivity, but their clinical application has been severely hampered by the poorly defined Borrelia antigens and nonstandardized LTT formats used. In this study, we describe the development and clinical relevance of a novel LTT using a validated format (MELISA) together with well-defined recombinant Borrelia-specific antigens. From an initial screening of 244 patients with suspected Borrelia infection or disease, 4 informative recombinant antigens were selected: OspC (Borrelia afzelii), p41-1 (Borrelia garinii), p41-2 (B. afzelii), and p100 (B. afzelii). Thereafter, 30 seronegative healthy controls were tested in LTT-MELISA(R) to determine specificity, 68 patients were tested in parallel to determine reproducibility, and 54 lymphocyte-reactive symptomatic patients were tested before and after antibiotic therapy to assess clinical relevance. Most (86.2%) of the 36.9% (90/244) LTT-MELISA positive patients were seropositive and showed symptoms of active LB. Specificity was 96.7% and reproducibility 92.6%. After therapy, most patients (90.7%) showed negative or markedly reduced lymphocyte reactivity correlating with clinical improvement. This novel LTT-MELISA assay appears to correlate with active LB and may have diagnostic relevance in confirming LB in clinically and serologically ambiguous cases. PMID:16876371

  18. Increase in Ticks and Lyme Borreliosis, Yet Research into Its Prevention on the Wane.

    Science.gov (United States)

    Beaujean, Desirée; Crutzen, Rik; Kengen, Cindy; van Steenbergen, Jim; Ruwaard, Dirk

    2016-05-01

    There is increased concern about the upward incidence of Lyme Borreliosis (LB) in Europe, the United States, Asia, and Northern Africa. However, effective measures to control tick populations or vaccines for LB are not yet available. Therefore, behavioral measures including avoidance of areas inhabited by ticks, performing routine body checks, using protective clothing, and the application of tick repellents are of great importance. Unfortunately, acceptance and uptake of many of these preventive behaviors are currently low. Hence, effective health education and public health communication aimed at promoting the uptake of preventive behaviors regarding tick bites and LB are urgently needed. In 2012, Mowbray recommended to conduct more research aimed at improving evidence-based insights regarding the promotion of preventive behaviors among the general public when exposed to the risk of LB. We fully agree with Mowbray and repeated her systematic review in May 2015 covering the period 1995-May 2015. Unfortunately, our review yielded exactly the same studies as already included in the review by Mowbray. Therefore, we again sound the alarm bell, just as Mowbray did a few years ago. As long as there are no effective measures for controlling tick populations and there is no vaccine available, we rely solely on health education and communication efforts to prevent tick bites and LB. We call on researchers and funders to prioritize research in the field of public health interventions for tick bites and LB because, in the words of Benjamin Franklin, "an ounce of prevention is worth a pound of cure." PMID:26901844

  19. Evaluation of Six Recombinant Proteins for Serological Diagnosis of Lyme Borreliosis in China

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; LIU Hui Xin; ZHANG Lin; HOU Xue Xia; WAN Kang Lin; HAO Qin

    2016-01-01

    ObjectiveIn this study, we evaluated the diagnostic efficiency of six recombinant proteins for the serodiagnosis of Lyme borreliosis (LB) and screened out the appropriate antigens to support the production of a Chinese clinical ELISA (enzyme-linked immunosorbent assay) kit for LB. MethodsSix recombinant antigens, Fla B.g, OspC B.a, OspC B.g, P39 B.g, P83 B.g, and VlsE B.a, were used for ELISA to detect serum antibodies in LB, syphilis, and healthy controls. The ELISA results were used to generate receiver operating characteristic (ROC) curves, and the sensitivity and specificity of each protein was evaluated. All recombinant proteins were evaluated and screened by using logistic regression models. ResultsTwo IgG (VlsE and OspC B.g) and two IgM (OspC B.g and OspC B.a) antigens were left by the logistic regression model screened. VlsE had the highest specificity for syphilis samples in the IgG test (87.7%,P ConclusionThree recombinant antigens, OspC B.g, OspC B.a, and VlsE B.a, were useful for ELISAs of LB. Additionally, the interaction between OspC B.a and Fla B.g should be examined in future research.

  20. Borreliose de Lyme simile: uma doença emergente e relevante para a dermatologia no Brasil Lyme borreliosis simile: an emergent and relevant disease to dermatology in Brazil

    Directory of Open Access Journals (Sweden)

    Adivaldo Henrique da Fonseca

    2005-04-01

    Full Text Available Neste trabalho de revisão são apresentadas doenças relacionadas com espiroquetas do gênero Borrelia, agentes etiológicos de diferentes enfermidades comuns ao homem e a animais. Enfatizou-se a Borrelia burgdorferi lato sensu, que inclui diferentes espécies causadoras de doenças e com envolvimento sistêmico, com interesse em várias especialidades médicas, como dermatologia, reumatologia, cardiologia e neurologia. Considerando que existem diferenças quanto ao agente etiológico, além dos aspectos clínicos e laboratoriais, quando comparada com a borreliose de Lyme causada pelas Borrelia burgdorferi, B. garinii e B. afzelli, a infecção no Brasil deve ser referida como borreliose de Lyme simile. O eritema migratório recidivante é a principal manifestação clínica da borreliose existente tanto no Brasil como nos demais países. Essa lesão clássica está relacionada com a picada do carrapato vetor e inicia-se como uma mácula ou pápula cutânea avermelhada, de caráter expansivo, eventualmente surgem lesões semelhantes múltiplas a distância. A manifestação clínica da enfermidade, em especial o envolvimento cutâneo, é o parâmetro diagnóstico mais relevante, e os exames complementares sorológicos confirmam a suspeita clínica.This review article presents diseases related to spirochetes of the genus Borrelia, which are the etiological agents of many human and animal diseases. Focus was given to the Borrelia burgdorferi sensu lato complex, including nine different species that cause diseases often with multisystemic involvement and raising interest to many medical specialties, such as Dermatology, Rheumatology, Cardiology and Neurology. Due to differences concerning the etiologic agent, clinical and laboratorial presentations, when comparing with Borrelia burgdorferi, B. garinii and B. afzelli, the infection must be referred as Lyme disease-like illness in Brazil. The recurrent erythema migrans is the main clinical

  1. Bacterial Amyloid and DNA are Important Constituents of Senile Plaques: Further Evidence of the Spirochetal and Biofilm Nature of Senile Plaques

    Science.gov (United States)

    Miklossy, Judith

    2016-01-01

    It has long been known that spirochetes form clumps or micro colonies in vitro and in vivo. Cortical spirochetal colonies in syphilitic dementia were considered as reproductive centers for spirochetes. Historic and recent data demonstrate that senile plaques in Alzheimer’s disease (AD) are made up by spirochetes. Spirochetes, are able to form biofilm in vitro. Senile plaques are also reported to contain elements of biofilm constituents. We expected that AβPP and Aβ (the main components of senile plaques) also occur in pure spirochetal biofilms, and bacterial DNA (an important component of biofilm) is also present in senile plaques. Histochemical, immunohistochemical, and in situ hybridization techniques and the TUNEL assay were used to answer these questions. The results obtained demonstrate that Aβ and DNA, including spirochete-specific DNA, are key components of both pure spirochetal biofilms and senile plaques in AD and confirm the biofilm nature of senile plaques. These results validate validate previous observations that AβPP and/or an AβPP-like amyloidogenic protein are an integral part of spirochetes, and indicate that bacterial and host derived Aβ are both constituents of senile plaques. DNA fragmentation in senile plaques further confirms their bacterial nature and provides biochemical evidence for spirochetal cell death. Spirochetes evade host defenses, locate intracellularly, form more resistant atypical forms and notably biofilms, which contribute to sustain chronic infection and inflammation and explain the slowly progressive course of dementia in AD. To consider co-infecting microorganisms is equally important, as multi-species biofilms result in a higher resistance to treatments and a more severe dementia. PMID:27314530

  2. Enfermedad de Lyme (Borreliosis de Lyme) en Costa Rica Lyme disease in Costa Rica, a case report

    OpenAIRE

    Ricardo Boza-Cordero

    2011-01-01

    La enfermedad de Lyme o borreliosis de Lyme es una zoonosis transmitida por garrapatas del género Ixodes y producida por la espiroqueta Borrelia burgdorferi. Ha sido descrita principalmente en Norteamérica, Europa y Asia, y se caracteriza clínicamente por una presentación en tres etapas: inicial con eritema migrans que comienza alrededor de la picadura de la garrapata; infección diseminada con fiebre, ataque al estado general, artritis migratoria, linfadenopatías, alteraciones neurológicas y ...

  3. Diagnostic Value of PCR for Detection of Borrelia burgdorferi in Skin Biopsy and Urine Samples from Patients with Skin Borreliosis

    OpenAIRE

    Brettschneider, S; Bruckbauer, H.; Klugbauer, N; Hofmann, H.

    1998-01-01

    Skin biopsies of 36 patients with erythema migrans and acrodermatitis chronica atrophicans (ACA) before therapy and those of 8 patients after therapy were examined for Borrelia burgdorferi DNA by PCR. Skin biopsies of 27 patients with dermatological diseases other than Lyme borreliosis and those of 10 healthy persons were examined as controls. Two different primer sets targeting 23S rRNA (PCR I) and 66-kDa protein (PCR II) genes were used. PCR was performed with freshly frozen tissue (FFT) an...

  4. Development of a System for Expressing Heterologous Genes in the Oral Spirochete Treponema denticola and Its Use in Expression of the Treponema pallidum flaA Gene

    OpenAIRE

    Chi, Bo; Chauhan, Sarita; Kuramitsu, Howard

    1999-01-01

    The present communication describes the construction of a new Escherichia coli-Treponema denticola shuttle vector based on the naturally occurring spirochete plasmid pTS1 and the expression of the heterologous T. pallidum flaA gene from the plasmid in T. denticola. This new shuttle vector system should prove useful in characterizing virulence factors from unculturable pathogenic spirochetes.

  5. Development of a system for expressing heterologous genes in the oral spirochete Treponema denticola and its use in expression of the Treponema pallidum flaA gene.

    Science.gov (United States)

    Chi, B; Chauhan, S; Kuramitsu, H

    1999-07-01

    The present communication describes the construction of a new Escherichia coli-Treponema denticola shuttle vector based on the naturally occurring spirochete plasmid pTS1 and the expression of the heterologous T. pallidum flaA gene from the plasmid in T. denticola. This new shuttle vector system should prove useful in characterizing virulence factors from unculturable pathogenic spirochetes. PMID:10377154

  6. A novel animal model of Borrelia recurrentis louse-borne relapsing fever borreliosis using immunodeficient mice.

    Directory of Open Access Journals (Sweden)

    Christer Larsson

    Full Text Available Louse-borne relapsing fever (LBRF borreliosis is caused by Borrelia recurrentis, and it is a deadly although treatable disease that is endemic in the Horn of Africa but has epidemic potential. Research on LBRF has been severely hampered because successful infection with B. recurrentis has been achieved only in primates (i.e., not in other laboratory or domestic animals. Here, we present the first non-primate animal model of LBRF, using SCID (-B, -T cells and SCID BEIGE (-B, -T, -NK cells immunocompromised mice. These animals were infected with B. recurrentis A11 or A17, or with B. duttonii 1120K3 as controls. B. recurrentis caused a relatively mild but persistent infection in SCID and SCID BEIGE mice, but did not proliferate in NUDE (-T and BALB/c (wild-type mice. B. duttonii was infectious but not lethal in all animals. These findings demonstrate that the immune response can limit relapsing fever even in the absence of humoral defense mechanisms. To study the significance of phagocytic cells in this context, we induced systemic depletion of such cells in the experimental mice by injecting them with clodronate liposomes, which resulted in uncontrolled B. duttonii growth and a one-hundred-fold increase in B. recurrentis titers in blood. This observation highlights the role of macrophages and other phagocytes in controlling relapsing fever infection. B. recurrentis evolved from B. duttonii to become a primate-specific pathogen that has lost the ability to infect immunocompetent rodents, probably through genetic degeneration. Here, we describe a novel animal model of B. recurrentis based on B- and T-cell-deficient mice, which we believe will be very valuable in future research on LBRF. Our study also reveals the importance of B-cells and phagocytes in controlling relapsing fever infection.

  7. Mitogenomes reveal diversity of the European Lyme borreliosis vector Ixodes ricinus in Italy.

    Science.gov (United States)

    Carpi, Giovanna; Kitchen, Andrew; Kim, Hie Lim; Ratan, Aakrosh; Drautz-Moses, Daniela I; McGraw, John J; Kazimirova, Maria; Rizzoli, Annapaola; Schuster, Stephan C

    2016-08-01

    In Europe, the Ixodes ricinus tick is the most important vector of the etiological agents of Lyme borreliosis and several other emerging tick-borne diseases. Because tick-borne pathogens are dependent on their vectors for transmission, understanding the vector population structure is crucial to inform public health research of pathogen dynamics and spread. However, the population structure and dynamics of this important vector species are not well understood as most genetic studies utilize short mitochondrial and nuclear sequences with little diversity. Herein we obtained and analyzed complete mitochondrial genome (hereafter "mitogenome") sequences to better understand the genetic diversity and the population structure of I. ricinus from two long-standing tick-borne disease foci in northern Italy. Complete mitogenomes of 23 I. ricinus ticks were sequenced at high coverage. Out of 23 mitogenome sequences we identified 17 unique haplotypes composed of 244 segregating sites. Phylogenetic reconstruction using 18 complete mitogenome sequences revealed the coexistence of four highly divergent I. ricinus maternal lineages despite the narrow spatial scale over which these samples were obtained (100km). Notably, the estimated coalescence time of the 18 mitogenome haplotypes is ∼427 thousand years ago (95% HPD 330, 540). This divergence between I. ricinus lineages is consistent with the mitochondrial diversity of other arthropod vector species and indicates that long-term I. ricinus populations may have been less structured and larger than previously thought. Thus, this study suggests that a rapid and accurate retrieval of full mitochondrial genomes from this disease vector enables fine-resolution studies of tick intraspecies genetic relationships, population differentiation, and demographic history. PMID:27165938

  8. Characterization of spirochetal isolates from arthropods collected in South Moravia, Czech Republic, using fatty acid methyl esters analysis

    Czech Academy of Sciences Publication Activity Database

    Čechová, L.; Durnová, E.; Šikutová, Silvie; Halouzka, Jiří; Němec, M.

    2004-01-01

    Roč. 808, č. 2 (2004), s. 249-254. ISSN 1570-0232 R&D Projects: GA ČR GA206/03/0726 Institutional research plan: CEZ:AV0Z6093917 Keywords : spirochetes * arthropods * fatty acid methyl esters Subject RIV: EE - Microbiology, Virology Impact factor: 2.176, year: 2004

  9. Bovine Immune Response to Papillomatous Digital Dermatitis (PDD)-Associated Spirochetes are Skewed in Isolate Reactivity and Subclass Elicitation

    Science.gov (United States)

    Background: Papillomatous digital dermatitis (PDD), also known as hairy heel wart, is a growing cause of lameness of cows in the U.S. dairy industry. Previous work using lesion material from a dairy farm in Iowa resulted in the isolation of four different Treponema phagedenis-like spirochetes (1A, 3...

  10. Serological, clinical and epidemiological aspects of Lyme borreliosis in Mures County, Romania

    Directory of Open Access Journals (Sweden)

    Țilea Brîndușa

    2014-06-01

    Full Text Available Borrelioza Lyme (BL este cea mai frecventă infecţie transmisă de căpuşe din genul Ixodes, atât în Statele Unite ale Americii (SUA, cât şi în Europa. Obiectivele studiului au constat în monitorizarea incidenţei şi a manifestărilor clinice ale bolii în judeţul Mureș. Material şi metodă. Studiul s-a efectuat pe o perioadă de 2 ani, 1 ianuarie 2010 - 31 decembrie 2011, pe un număr de 120 pacienţi. Diagnosticul cert sau probabil al BL s-a stabilit pe baza criteriilorCenters for Diseases Control and Prevention (CDC, Atlanta, SUA şi European Union Concerted Action on Lyme Borreliosis (EUCALB şi anume epidemiologice, clinice şi serologice. Pentru identificarea anticorpilor antiBb IgM, IgG din ser şi LCR s-au utilizat tehnicile ELISA şi Western-Blot. Rezultate. În anul 2010 s-au înregistrat 44 cazuri, iar în anul 2011, 76 cazuri. Conform definiţiei de caz, 106 cazuri au fost confirmate, 14 probabile. BL a fost evidenţiată cu o frecvenţă mai ridicată la copii, adulţi tineri şi adulţi, comparativ cu grupa de vârstă peste 60 ani. Incidenţa afecţiunii a fost mai ridicată la sexul feminin, 68 pacienţi (56,66% faţă de sexul masculin 52 pacienţi (43,33%, cu o pondere, mai crescută la persoanele din mediul urban, 78 pacienţi (65,0%, comparativ cu cele din mediul rural 42 pacienţi (35,0%. Manifestările clinice au fost acute de tipul eritemului migrator (EM la 64,16 din pacienţi, neurologice la 22,50% pacienţi, articulare la 1,66% pacienţi şi cardiace la 0,83% din cazuri. Concluzii. În judetul Mureș s-a constatat o incidenţă în creştere a bolii în anul 2011 comparativ cu anul 2010. Manifestările clinice predominante au fost cele acute dermatologice, neurologice.

  11. Search for eukaryotic motility proteins in spirochetes: immunological detection of a tektin-like protein in Spirochaeta halophila.

    Science.gov (United States)

    Barth, A L; Stricker, J A; Margulis, L

    1991-01-01

    The serial endosymbiotic theory (SET) for the spirochete origin of undulipodia (cilia and eukaryotic flagella) predicts that a greater number of axonemal proteins will show homology to spirochete than to other bacterial proteins. To continue testing, the SET proteins associated with eukaryotic motility (tektin, centrin and calmodulin) were sought in Spirochaeta halophila. Western blot immunological detection techniques (for tektin and centrin) and two-dimensional gel analysis (for calmodulin) were used. Tektins are filamentous proteins extending the length of the axoneme in sperm tails and other undulipodia. Whole cell extracts of S. halophila were probed with antibodies made against three sea urchin (Lytechinus pictus) sperm axonemal tektins (tektins A, B, and C). In the spirochetes, one tektin-like protein was detected as a band on Western blots (a C tektin.) An antibody made against Lytechinus pictus sperm tail axonemes, affinity-purified against the C tektin of another sea urchin, Stronglyocentrotus purpuratus, bound to a 30 kDa protein from Spirochaeta halophila. The C tektin epitope was not detected in Escherichia coli. Both the poly- and monoclonal anti-centrin antibodies cross-reacted with multiple proteins in the control alga (Tetraselmis striata) and in the putatively negative control bacterium E. coli. No cross reaction was seen between any anti-centrin antibody and S. halophila. Neither did a two-dimensional gel analysis reveal the presence of calmodulin in these spirochetes or in the two other prokaryotes tested (Spiroplasma citri, Acholeplasma laidlawii). Although neither centrin nor calmodulin were detected, a 30 kDa tektin-like protein apparently is present in these spirochetes. PMID:1863720

  12. Reservoir competence of Microtus pennsylvanicus (Rodentia: Cricetidae) for the Lyme disease spirochete, Borrelia burgdorferi

    Science.gov (United States)

    Markowski, D.; Ginsberg, H.S.; Hyland, K.E.; Hu, R.

    1998-01-01

    The reservoir competence of the meadow vole, Microtus pennsylvanicus Ord, for the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner was established on Patience Island, RI. Meadow voles were collected from 5 locations throughout Rhode Island. At 4 of the field sites, M. pennsylvanicus represented only 4.0% (n = 141) of the animals captured. However, on Patience Island, M. pennsylvanicus was the sole small mammal collected (n = 48). Of the larval Ixodes scapularis Say obtained from the meadow voles on Patience Island, 62% (n = 78) was infected with B. burgdorferi. Meadow voles from all 5 locations were successfully infected with B. burgdorferi in the laboratory and were capable of passing the infection to xenodiagnostic I. scapularis larvae for 9 wk. We concluded that M. pennsylvanicus was physiologically capable of maintaining B. burgdorferi infection. However, in locations where Peromyscus leucopus (Rafinesque) is abundant, the role of M. pennsylvanicus as a primary reservoir for B. burgdorferi was reduced.

  13. Neelaredoxin, an iron-binding protein from the syphilis spirochete, Treponema pallidum, is a superoxide reductase.

    Science.gov (United States)

    Jovanović, T; Ascenso, C; Hazlett, K R; Sikkink, R; Krebs, C; Litwiller, R; Benson, L M; Moura, I; Moura, J J; Radolf, J D; Huynh, B H; Naylor, S; Rusnak, F

    2000-09-15

    Treponema pallidum, the causative agent of venereal syphilis, is a microaerophilic obligate pathogen of humans. As it disseminates hematogenously and invades a wide range of tissues, T. pallidum presumably must tolerate substantial oxidative stress. Analysis of the T. pallidum genome indicates that the syphilis spirochete lacks most of the iron-binding proteins present in many other bacterial pathogens, including the oxidative defense enzymes superoxide dismutase, catalase, and peroxidase, but does possess an orthologue (TP0823) for neelaredoxin, an enzyme of hyperthermophilic and sulfate-reducing anaerobes shown to possess superoxide reductase activity. To analyze the potential role of neelaredoxin in treponemal oxidative defense, we examined the biochemical, spectroscopic, and antioxidant properties of recombinant T. pallidum neelaredoxin. Neelaredoxin was shown to be expressed in T. pallidum by reverse transcriptase-polymerase chain reaction and Western blot analysis. Recombinant neelaredoxin is a 26-kDa alpha(2) homodimer containing, on average, 0.7 iron atoms/subunit. Mössbauer and EPR analysis of the purified protein indicates that the iron atom exists as a mononuclear center in a mixture of high spin ferrous and ferric oxidation states. The fully oxidized form, obtained by the addition of K(3)(Fe(CN)(6)), exhibits an optical spectrum with absorbances at 280, 320, and 656 nm; the last feature is responsible for the protein's blue color, which disappears upon ascorbate reduction. The fully oxidized protein has a A(280)/A(656) ratio of 10.3. Enzymatic studies revealed that T. pallidum neelaredoxin is able to catalyze a redox equilibrium between superoxide and hydrogen peroxide, a result consistent with it being a superoxide reductase. This finding, the first description of a T. pallidum iron-binding protein, indicates that the syphilis spirochete copes with oxidative stress via a primitive mechanism, which, thus far, has not been described in pathogenic

  14. Susceptibility to Ticks and Lyme Disease Spirochetes Is Not Affected in Mice Coinfected with Nematodes.

    Science.gov (United States)

    Maaz, Denny; Rausch, Sebastian; Richter, Dania; Krücken, Jürgen; Kühl, Anja A; Demeler, Janina; Blümke, Julia; Matuschka, Franz-Rainer; von Samson-Himmelstjerna, Georg; Hartmann, Susanne

    2016-05-01

    Small rodents serve as reservoir hosts for tick-borne pathogens, such as the spirochetes causing Lyme disease. Whether natural coinfections with other macroparasites alter the success of tick feeding, antitick immunity, and the host's reservoir competence for tick-borne pathogens remains to be determined. In a parasitological survey of wild mice in Berlin, Germany, approximately 40% of Ixodes ricinus-infested animals simultaneously harbored a nematode of the genus Heligmosomoides We therefore aimed to analyze the immunological impact of the nematode/tick coinfection as well as its effect on the tick-borne pathogen Borrelia afzelii Hosts experimentally coinfected with Heligmosomoides polygyrus and larval/nymphal I. ricinus ticks developed substantially stronger systemic type 2 T helper cell (Th2) responses, on the basis of the levels of GATA-3 and interleukin-13 expression, than mice infected with a single pathogen. During repeated larval infestations, however, anti-tick Th2 reactivity and an observed partial immunity to tick feeding were unaffected by concurrent nematode infections. Importantly, the strong systemic Th2 immune response in coinfected mice did not affect susceptibility to tick-borne B. afzelii An observed trend for decreased local and systemic Th1 reactivity against B. afzelii in coinfected mice did not result in a higher spirochete burden, nor did it facilitate bacterial dissemination or induce signs of immunopathology. Hence, this study indicates that strong systemic Th2 responses in nematode/tick-coinfected house mice do not affect the success of tick feeding and the control of the causative agent of Lyme disease. PMID:26883594

  15. Association of spirochetal infection with Morgellons disease [v1; ref status: indexed, http://f1000r.es/8g

    Directory of Open Access Journals (Sweden)

    Marianne J Middelveen

    2013-01-01

    Full Text Available Morgellons disease (MD is an emerging multisystem illness characterized by skin lesions with unusual filaments embedded in or projecting from epithelial tissue. Filament formation results from abnormal keratin and collagen expression by epithelial-based keratinocytes and fibroblasts. Recent research comparing MD to bovine digital dermatitis, an animal infectious disease with similar skin features, provided clues that spirochetal infection could play an important role in the human disease as it does in the animal illness. Based on histological staining, immunofluorescent staining, electron microscopic imaging and polymerase chain reaction, we report the detection of Borrelia spirochetes in dermatological tissue of  four randomly-selected MD patients. The association of MD with spirochetal infection provides evidence that this infection may be a significant factor in the illness and refutes claims that MD lesions are self-inflicted and that people suffering from this disorder are delusional. Molecular characterization of the Borrelia spirochetes found in MD patients is warranted.

  16. Vaccination with the variable tick protein of the relapsing fever spirochete Borrelia hermsii protects mice from infection by tick-bite

    OpenAIRE

    Krajacich, Benjamin J; Lopez, Job E.; Raffel, Sandra J.; Schwan, Tom G.

    2015-01-01

    Background Tick-borne relapsing fevers of humans are caused by spirochetes that must adapt to both warm-blooded vertebrates and cold-blooded ticks. In western North America, most human cases of relapsing fever are caused by Borrelia hermsii, which cycles in nature between its tick vector Ornithodoros hermsi and small mammals such as tree squirrels and chipmunks. These spirochetes alter their outer surface by switching off one of the bloodstream-associated variable major proteins (Vmps) they p...

  17. Study of the climatic change impact on vector-borne diseases in West Africa: the case of tick-borne borreliosis and malaria

    International Nuclear Information System (INIS)

    Malaria and tick-borne borreliosis are the two first causes of morbidity due to vector-borne diseases in a large part of Sudan-sahelian West Africa. They are also the two tropical diseases which have been the most affected by climatic change in recent years. In the case of tick-borne borreliosis it has been shown in Senegal that the persistence of drought since the years 70 has been associated with a considerable extension of the geographic range of diseases and the vector tick A-sonrai, a species that was in the past limited to the Sahara and Sahel. In the case of malaria, drought has strongly reduced in these same regions of Africa the distribution, abundance and infection rate of Anopheline mosquitoes, but without any significant reduction of the burden of malaria for most populations concerned. The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs only explain part of this phenomenon. (A.L.B.)

  18. Application of Nanotrap technology for high sensitivity measurement of urinary outer surface protein A carboxyl-terminus domain in early stage Lyme borreliosis

    OpenAIRE

    Magni, Ruben; Espina, Benjamin H.; Shah, Ketul; Lepene, Benjamin; Mayuga, Christine; Douglas, Temple A.; Espina, Virginia; Rucker, Sally; Dunlap, Ross; Petricoin, Emanuel F. III; Kilavos, Mary Frekko; Poretz, Donald M.; Irwin, Gilbert R.; Shor, Samuel M.; Lance A. Liotta

    2015-01-01

    Objectives Prompt antibiotic treatment of early stage Lyme borreliosis (LB) prevents progression to severe multisystem disease. There is a clinical need to improve the diagnostic specificity of early stage Lyme assays in the period prior to the mounting of a robust serology response. Using a novel analyte harvesting nanotechnology, Nanotrap particles, we evaluated urinary Borrelia Outer surface protein A (OspA) C-terminus peptide in early stage LB before and after treatment, and in patients s...

  19. Diagnostic use of the lymphocyte transformation test-memory lymphocyte immunostimulation assay in confirming active Lyme borreliosis in clinically and serologically ambiguous cases.

    Science.gov (United States)

    Puri, Basant K; Segal, Daniel Rm; Monro, Jean A

    2014-01-01

    The aim of this study was to carry out an independent evaluation of the proposition that the lymphocyte transformation test-memory lymphocyte immunostimulation assay (LTT-MELISA) may be diagnostically useful in the confirmation of active Lyme borreliosis in clinically and serologically ambiguous cases. Blood samples from 54 patients consecutively presenting to a British center with clinical suspicion of Lyme borreliosis were tested for this disease by immunoglobulin M (IgM) and immunoglobulin G (IgG) Western blots and by LTT-MELISA. Forty-five of these patients had Western blot results which were negative for both IgM and IgG by the criteria of the Centers for Disease Control and Prevention (CDC); of these patients, 19 (42%) were LTT-MELISA-positive. Two of the patients who had IgM positive results by the CDC criteria were LTT-MELISA-negative. It is concluded that, for putative European-acquired Lyme borreliosis infections, it would be sensible to carry out both the LTT-MELISA and Western blot assay. PMID:25664127

  20. Biochemical and molecular characterization of Treponema phagedenis-like spirochetes isolated from a bovine digital dermatitis lesion

    OpenAIRE

    Wilson-Welder, Jennifer H.; Elliott, Margaret K.; Zuerner, Richard L.; Bayles, Darrell O.; Alt, David P.; Stanton, Thad B.

    2013-01-01

    Background Bovine papillomatous digital dermatitis (DD) is the leading cause of lameness in dairy cattle and represents a serious welfare and economic burden. Found primarily in high production dairy cattle worldwide, DD is characterized by the development of an often painful red, raw ulcerative or papillomatous lesion frequently located near the interdigital cleft and above the bulbs of the heel. While the exact etiology is unknown, several spirochete species have been isolated from lesion m...

  1. Sensitivity of spirochetes from \\kur{Borrelia burgdorferi} sensu lato complex to human complement: infection potential of selected species

    OpenAIRE

    Tichá, Lucie

    2015-01-01

    Sensitivity of spirochetes from Borrelia burgdorferi sensu lato complex to serum complement of humans of different age and sex was analyzed. Complement-mediated Borrelia killing was observed in different combination of serum and selected Borrelia genospecies. The obtained results confirmed that age itself does not influence the sensitivity of human to Borrelia infection. However, the females seem to be more vulnerable to it. Each of ten tested Borrelia species was proved to be potentially inf...

  2. Two ways of experimental infection of Ixodes ricinus ticks (Acari: Ixodidae) with spirochetes of Borrelia burgdorferi sensu lato complex

    Czech Academy of Sciences Publication Activity Database

    Fišerová, Lenka; Černá, Kateřina; Horká, Helena; Kopecký, Jan

    2008-01-01

    Roč. 55, č. 2 (2008), s. 150-154. ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Lyme disease spirochete * Borrelia burgdorferi * Borrelia baronii * Borrelia afzelii * tick * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 1.307, year: 2008

  3. Heterologous Expression of the Treponema pallidum Laminin-Binding Adhesin Tp0751 in the Culturable Spirochete Treponema phagedenis▿

    OpenAIRE

    Cameron, Caroline E.; Kuroiwa, Janelle M. Y.; Yamada, Mitsunori; Francescutti, Teresa; Chi, Bo; Kuramitsu, Howard K.

    2008-01-01

    Treponema pallidum subsp. pallidum, the causative agent of syphilis, is an unculturable, genetically intractable bacterium. Here we report the use of the shuttle vector pKMR4PEMCS for the expression of a previously identified T. pallidum laminin-binding adhesin, Tp0751, in the nonadherent, culturable spirochete Treponema phagedenis. Heterologous expression of Tp0751 in T. phagedenis was confirmed via reverse transcriptase PCR analysis with tp0751 gene-specific primers and immunofluorescence a...

  4. A Novel Surface Antigen of Relapsing Fever Spirochetes Can Discriminate between Relapsing Fever and Lyme Borreliosis▿ † ‡

    Science.gov (United States)

    Lopez, Job E.; Schrumpf, Merry E.; Nagarajan, Vijayaraj; Raffel, Sandra J.; McCoy, Brandi N.; Schwan, Tom G.

    2010-01-01

    In a previous immunoproteome analysis of Borrelia hermsii, candidate antigens that bound IgM antibodies from mice and patients infected with relapsing fever spirochetes were identified. One candidate that was identified is a hypothetical protein with a molecular mass of 57 kDa that we have designated Borrelia immunogenic protein A (BipA). This protein was further investigated as a potential diagnostic antigen for B. hermsii given that it is absent from the Borrelia burgdorferi genome. The bipA locus was amplified and sequenced from 39 isolates of B. hermsii that had been acquired from western North America. bipA was also expressed as a recombinant fusion protein. Serum samples from mice and patients infected with B. hermsii or B. burgdorferi were used to confirm the immunogenicity of the recombinant protein in patients infected with relapsing fever spirochetes. Lastly, in silico and experimental analysis indicated that BipA is a surface-exposed lipoprotein in B. hermsii. These findings enhance the capabilities of diagnosing infection with relapsing fever spirochetes. PMID:20147497

  5. Outer Surface Protein A Protects Lyme Disease Spirochetes from Acquired Host Immunity in the Tick Vector▿

    Science.gov (United States)

    Battisti, James M.; Bono, James L.; Rosa, Patricia A.; Schrumpf, Merry E.; Schwan, Tom G.; Policastro, Paul F.

    2008-01-01

    The Lyme disease spirochete Borrelia burgdorferi alters the expression of outer surface protein (osp) genes as the bacterium cycles between ticks and mammals. OspA is produced as borreliae enter the tick vector and remains a major surface antigen during midgut colonization. To elucidate the role of OspA in the vector, we created an insertional deletion of ospA in strain B31-A3. The ospA mutant infects mice when it is injected intradermally and is acquired by larval ticks fed on these mice, where it persists through the molt to the nymph stage. Bacterial survival rates in artificially infected tick larvae fed on naïve mice were compared with those in the vector fed on immune mice. The ospA mutant proliferates in larvae if it is exposed to blood from naïve mice, but it declines in density after larval feeding if the blood is from immune mice. When uninfected larvae are fed on B-cell-deficient mice infected with the ospA mutant, larvae show borrelial densities and persistence that are significantly greater than those fed on infected, immunocompetent mice. We conclude that OspA serves a critical antibody-shielding role during vector blood meal uptake from immune hosts and is not required for persistence in the tick vector. PMID:18779341

  6. Reservoir competence of native North American birds for the Lyme disease spirochete, Borrelia burgdorferi

    Science.gov (United States)

    Ginsberg, H.S.; Buckley, P.A.; Balmforth, M.G.; Zhioua, E.; Mitra, Siddhartha; Buckley, F.G.

    2005-01-01

    Reservoir competence of the Lyme disease spirochete, Borrelia burgdorferi, was tested for six species of native North American birds: American Robin, Gray Catbird, Brown Thrasher, Eastern Towhee, Song Sparrow, and Northern Cardinal. Wild birds collected by mistnetting on Fire Island, NY, were held in a field lab in cages over water, and locally collected larval ticks were placed on the birds, harvested from the water after engorgement, and tested for infection by DFA after molting to the nymphal stage. American Robins were competent reservoirs, infecting 16.1% of larvae applied to wild-caught birds, compared to 0% of control ticks placed on uninfected lab mice. Robins that were previously infected in the lab by nymphal feeding infected 81.8% of applied larvae. Wild-caught Song Sparrows infected 4.8% of applied larvae, and 21.1% when infected by nymphal feeding. Results suggest moderate levels of reservoir competence for Northern Cardinals, lower levels for Gray Catbirds, and little evidence of reservoir competence for Eastern Towhees or Brown Thrashers. Lower infection rates in larvae applied to wild-caught birds compared to birds infected in the lab suggest that infected birds display temporal variability in infectiousness to larval ticks. Engorged larvae drop from birds abundantly during daylight hours, so the abundance of these bird species in the peridomestic environment suggests that they might contribute infected ticks to lawns and gardens.

  7. The Binary Protein Interactome of Treponema pallidum – The Syphilis Spirochete

    Science.gov (United States)

    Goll, Johannes; Häuser, Roman; McKevitt, Matthew T.; Palzkill, Timothy; Uetz, Peter

    2008-01-01

    Protein interaction networks shed light on the global organization of proteomes but can also place individual proteins into a functional context. If we know the function of bacterial proteins we will be able to understand how these species have adapted to diverse environments including many extreme habitats. Here we present the protein interaction network for the syphilis spirochete Treponema pallidum which encodes 1,039 proteins, 726 (or 70%) of which interact via 3,649 interactions as revealed by systematic yeast two-hybrid screens. A high-confidence subset of 991 interactions links 576 proteins. To derive further biological insights from our data, we constructed an integrated network of proteins involved in DNA metabolism. Combining our data with additional evidences, we provide improved annotations for at least 18 proteins (including TP0004, TP0050, and TP0183 which are suggested to be involved in DNA metabolism). We estimate that this “minimal” bacterium contains on the order of 3,000 protein interactions. Profiles of functional interconnections indicate that bacterial proteins interact more promiscuously than eukaryotic proteins, reflecting the non-compartmentalized structure of the bacterial cell. Using our high-confidence interactions, we also predict 417,329 homologous interactions (“interologs”) for 372 completely sequenced genomes and provide evidence that at least one third of them can be experimentally confirmed. PMID:18509523

  8. The cyclic-di-GMP signaling pathway in the Lyme disease spirochete, Borrelia burgdorferi

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    Elizabeth A. Novak

    2014-05-01

    Full Text Available In nature, the Lyme disease spirochete Borrelia burgdorferi cycles between the unrelated environments of the Ixodes tick vector and mammalian host. In order to survive transmission between hosts, B. burgdorferi must be able to not only detect changes in its environment, but also rapidly and appropriately respond to these changes. One manner in which this obligate parasite regulates and adapts to its changing environment is through cyclic-di-GMP (c-di-GMP signaling. c-di-GMP has been shown to be instrumental in orchestrating the adaptation of B. burgdorferi to the tick environment. B. burgdorferi possesses only one set of c-di-GMP-metabolizing genes (one diguanylate cyclase and two distinct phosphodiesterases and one c-di-GMP-binding PilZ-domain protein designated as PlzA. While studies in the realm of c-di-GMP signaling in B. burgdorferi have exploded in the last few years, there are still many more questions than answers. Elucidation of the importance of c-di-GMP signaling to B. burgdorferi may lead to the identification of mechanisms that are critical for the survival of B. burgdorferi in the tick phase of the enzootic cycle as well as potentially delineate a role (if any c-di-GMP may play in the transmission and virulence of B. burgdorferi during the enzootic cycle, thereby enabling the development of effective drugs for the prevention and/or treatment of Lyme disease.

  9. Ixodes tick saliva suppresses the keratinocyte cytokine response to TLR2/TLR3 ligands during early exposure to Lyme borreliosis.

    Science.gov (United States)

    Bernard, Quentin; Gallo, Richard L; Jaulhac, Benoît; Nakatsuji, Teruaki; Luft, Benjamin; Yang, Xiahoua; Boulanger, Nathalie

    2016-01-01

    Ixodes hard tick induces skin injury by its sophisticated biting process. Its saliva plays a key role to enable an efficient blood meal that lasts for several days. We hypothesized that this feeding process may also be exploited by pathogens to facilitate their transmission, especially in the context of arthropod-borne diseases. To test this, we used Lyme borreliosis as a model. This bacterial infection is caused by Borrelia burgdorferi sensu lato transmitted by Ixodes. We co-incubated Borrelia with human keratinocytes in the presence of poly (I: C), a dsRNA TLR3 agonist generated by skin injury. This induced a strong cytokine response from human primary keratinocytes that was much greater than that induced by Borrelia alone. OspC, a TLR2/1 agonist and a major surface lipoprotein of Borrelia also amplified the process. Interestingly, tick saliva inhibited cytokine responses by keratinocytes to these TLR agonists. We propose that Borrelia uses the immunoprivileged site produced by tick saliva to facilitate its transmission. PMID:26307945

  10. Borrelia burgdorferi CheD Promotes Various Functions in Chemotaxis and the Pathogenic Life Cycle of the Spirochete.

    Science.gov (United States)

    Moon, Ki Hwan; Hobbs, Gerry; Motaleb, M A

    2016-06-01

    Borrelia burgdorferi possesses a sophisticated chemotaxis signaling system; however, the roles of the majority of the chemotaxis proteins in the infectious life cycle have not yet been demonstrated. Specifically, the role of CheD during host colonization has not been demonstrated in any bacterium. Here, we systematically characterized the B. burgdorferi CheD homolog using genetics and biochemical and mouse-tick-mouse infection cycle studies. Bacillus subtilis CheD plays an important role in chemotaxis by deamidation of methyl-accepting chemotaxis protein receptors (MCPs) and by increasing the receptor kinase activity or enhancing CheC phosphatase activity, thereby regulating the levels of the CheY response regulator. Our biochemical analysis indicates that B. burgdorferi CheD significantly enhances CheX phosphatase activity by specifically interacting with the phosphatase. Moreover, CheD specifically binds two of the six MCPs, indicating that CheD may also modulate the receptor proteins. Although the motility of the cheD mutant cells was indistinguishable from that of the wild-type cells, the mutant did exhibit reduced chemotaxis. Importantly, the mutant showed significantly reduced infectivity in C3H/HeN mice via needle inoculation. Mouse-tick-mouse infection assays indicated that CheD is dispensable for acquisition or transmission of spirochetes; however, the viability of cheD mutants in ticks is marginally reduced compared to that of the wild-type or complemented cheD spirochetes. These data suggest that CheD plays an important role in the chemotaxis and pathogenesis of B. burgdorferi We propose potential connections between CheD, CheX, and MCPs and discuss how these interactions play critical roles during the infectious life cycle of the spirochete. PMID:27021244

  11. Development and validation of a FACS-based lipoprotein localization screen in the Lyme disease spirochete Borrelia burgdorferi

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    Slusser Joyce G

    2010-11-01

    Full Text Available Abstract Background In our previous studies on lipoprotein secretion in the Lyme disease spirochete Borrelia burgdorferi, we used monomeric red fluorescent protein 1 (mRFP1 fused to specifically mutated outer surface protein A (OspA N-terminal lipopeptides to gather first insights into lipoprotein sorting determinants. OspA:mRFP1 fusions could be detected by epifluorescence microscopy both in the periplasm and on the bacterial surface. To build on these findings and to complement the prior targeted mutagenesis approach, we set out to develop a screen to probe a random mutagenesis expression library for mutants expressing differentially localized lipoproteins. Results A Glu-Asp codon pair in the inner membrane-localized OspA20:mRFP1 fusion was chosen for mutagenesis since the two negative charges were previously shown to define the phenotype. A library of random mutants in the two codons was generated and expressed in B. burgdorferi. In situ surface proteolysis combined with fluorescence activated cell sorting (FACS was then used to screen for viable spirochetes expressing alternative subsurface OspA:mRFP1 fusions. Analysis of 93 clones randomly picked from a sorted cell population identified a total of 43 distinct mutants. Protein localization assays indicated a significant enrichment in the selected subsurface phenotype. Interestingly, a majority of the subsurface mutant proteins localized to the outer membrane, indicating their impairment in "flipping" through the outer membrane to the spirochetal surface. OspA20:mRFP1 remained the protein most restricted to the inner membrane. Conclusions Together, these results validate this FACS-based screen for lipoprotein localization and suggest a rather specific inner membrane retention mechanism involving membrane anchor-proximal negative charge patches in this model B. burgdorferi lipoprotein system.

  12. Diagnostic Value of Proteins of Three Borrelia Species (Borrelia burgdorferi Sensu Lato) and Implications for Development and Use of Recombinant Antigens for Serodiagnosis of Lyme Borreliosis in Europe

    OpenAIRE

    Hauser, Ulrike; Lehnert, Gisela; Wilske, Bettina

    1998-01-01

    More and more assays for the serodiagnosis of Lyme borreliosis (LB) are based on recombinant antigens. However, so far, there is no consensus as to which are the most specific and sensitive proteins and how they should be used in combination to obtain tests with the best discrimination abilities. The present study was preceded by a detailed analysis of Western blots (WB) using whole-cell lysates of Borrelia burgdorferi sensu stricto strain PKa2, B. afzelii PKo, and B. garinii PBi (U. Hauser, ...

  13. Borrelia-like spirochetes recovered from ticks and small mammals collected in the Atlantic Forest Reserve, Cotia county, State of São Paulo, Brazil

    OpenAIRE

    Abel IS; Marzagão G; NH Yoshinari; TTS Schumaker

    2000-01-01

    Forty-four marsupials, 77 rodents and 161 ticks were captured in an Atlantic Forest Reserve in Cotia county, State of São Paulo, where human cases of Lyme disease (LD) simile were reported. Twenty-one borrelia-like spirochete isolates were recovered from the mammals' blood and rodent livers or spleens, and triturated ticks inoculated into BSK II medium. Our results suggest that the reservoirs and ticks collected may harbor borrelia-like spirochetes, some of which have an antigenic similarity ...

  14. Statins reduce spirochetal burden and modulate immune responses in the C3H/HeN mouse model of Lyme disease.

    Science.gov (United States)

    Van Laar, Tricia A; Hole, Camaron; Rajasekhar Karna, S L; Miller, Christine L; Reddick, Robert; Wormley, Floyd L; Seshu, J

    2016-06-01

    Lyme disease (LD) is a systemic disorder caused by Borrelia burgdorferi. Lyme spirochetes encode for a functional 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR EC 1.1.1.88) serving as a rate limiting enzyme of the mevalonate pathway that contribute to components critical for cell wall biogenesis. Statins have been shown to inhibit B. burgdorferi in vitro. Using a mouse model of Lyme disease, we found that statins contribute to reducing bacterial burden and altering the murine immune response to favor clearance of spirochetes. PMID:26993029

  15. Imbalanced presence of Borrelia burgdorferi s.l. multilocus sequence types in clinical manifestations of Lyme borreliosis.

    Science.gov (United States)

    Coipan, E Claudia; Jahfari, Setareh; Fonville, Manoj; Oei, G Anneke; Spanjaard, Lodewijk; Takumi, Katsuhisa; Hovius, Joppe W R; Sprong, Hein

    2016-08-01

    In this study we used typing based on the eight multilocus sequence typing scheme housekeeping genes (MLST) and 5S-23S rDNA intergenic spacer (IGS) to explore the population structure of Borrelia burgdorferi sensu lato isolates from patients with Lyme borreliosis (LB) and to test the association between the B. burgdorferi s.l. sequence types (ST) and the clinical manifestations they cause in humans. Isolates of B. burgdorferi from 183 LB cases across Europe, with distinct clinical manifestations, and 257 Ixodes ricinus lysates from The Netherlands, were analyzed for this study alone. For completeness, we incorporated in our analysis also 335 European B. burgdorferi s.l. MLST profiles retrieved from literature. Borrelia afzelii and Borrelia bavariensis were associated with human cases of LB while Borrelia garinii, Borrelia lusitaniae and Borrelia valaisiana were associated with questing I. ricinus ticks. B. afzelii was associated with acrodermatitis chronica atrophicans, while B. garinii and B. bavariensis were associated with neuroborreliosis. The samples in our study belonged to 251 different STs, of which 94 are newly described, adding to the overall picture of the genetic diversity of Borrelia genospecies. The fraction of STs that were isolated from human samples was significantly higher for the genospecies that are known to be maintained in enzootic cycles by mammals (B. afzelii, B. bavariensis, and Borrelia spielmanii) than for genospecies that are maintained by birds (B. garinii and B. valaisiana) or lizards (B. lusitaniae). We found six multilocus sequence types that were significantly associated to clinical manifestations in humans and five IGS haplotypes that were associated with the human LB cases. While IGS could perform just as well as the housekeeping genes in the MLST scheme for predicting the infectivity of B. burgdorferi s.l., the advantage of MLST is that it can also capture the differential invasiveness of the various STs. PMID:27125686

  16. Cyclic di-GMP is essential for the survival of the lyme disease spirochete in ticks.

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    Ming He

    2011-06-01

    Full Text Available Cyclic dimeric GMP (c-di-GMP is a bacterial second messenger that modulates many biological processes. Although its role in bacterial pathogenesis during mammalian infection has been documented, the role of c-di-GMP in a pathogen's life cycle within a vector host is less understood. The enzootic cycle of the Lyme disease pathogen Borrelia burgdorferi involves both a mammalian host and an Ixodes tick vector. The B. burgdorferi genome encodes a single copy of the diguanylate cyclase gene (rrp1, which is responsible for c-di-GMP synthesis. To determine the role of c-di-GMP in the life cycle of B. burgdorferi, an Rrp1-deficient B. burgdorferi strain was generated. The rrp1 mutant remains infectious in the mammalian host but cannot survive in the tick vector. Microarray analyses revealed that expression of a four-gene operon involved in glycerol transport and metabolism, bb0240-bb0243, was significantly downregulated by abrogation of Rrp1. In vitro, the rrp1 mutant is impaired in growth in the media containing glycerol as the carbon source (BSK-glycerol. To determine the contribution of the glycerol metabolic pathway to the rrp1 mutant phenotype, a glp mutant, in which the entire bb0240-bb0243 operon is not expressed, was generated. Similar to the rrp1 mutant, the glp mutant has a growth defect in BSK-glycerol medium. In vivo, the glp mutant is also infectious in mice but has reduced survival in ticks. Constitutive expression of the bb0240-bb0243 operon in the rrp1 mutant fully rescues the growth defect in BSK-glycerol medium and partially restores survival of the rrp1 mutant in ticks. Thus, c-di-GMP appears to govern a catabolic switch in B. burgdorferi and plays a vital role in the tick part of the spirochetal enzootic cycle. This work provides the first evidence that c-di-GMP is essential for a pathogen's survival in its vector host.

  17. Rational diagnostic strategies for Lyme borreliosis in children and adolescents: recommendations by the Committee for Infectious Diseases and Vaccinations of the German Academy for Pediatrics and Adolescent Health.

    Science.gov (United States)

    Huppertz, H I; Bartmann, P; Heininger, U; Fingerle, V; Kinet, M; Klein, R; Korenke, G C; Nentwich, H J

    2012-11-01

    The varying clinical manifestations of Lyme borreliosis, transmitted by Ixodes ricinus and caused by Borrelia burgdorferi, frequently pose diagnostic problems. Diagnostic strategies vary between early and late disease manifestations and usually include serological methods. Erythema migrans is pathognomonic and does not require any further laboratory investigations. In contrast, the diagnosis of neuroborreliosis requires the assessment of serum and cerebrospinal fluid. Lyme arthritis is diagnosed in the presence of newly recognized arthritis and high-titer serum IgG antibodies against B. burgdorferi. The committee concludes the following recommendations: Borrelial serology should only be ordered in case of well-founded clinical suspicion for Lyme borreliosis, i.e., manifestations compatible with the diagnosis. Tests for borrelial genomic sequences in ticks or lymphocyte proliferation assays should not be ordered. When results of such tests or of serological investigations that were not indicated are available, they should not influence therapeutic decisions. Laboratories should be cautious when interpreting results of serological tests and abstain from giving therapeutic recommendations and from proposing retesting after some time without intimate knowledge of patient's history and disease manifestations. PMID:22782450

  18. Immune Evasion and Recognition of the Syphilis Spirochete in Blood and Skin of Secondary Syphilis Patients: Two Immunologically Distinct Compartments

    Science.gov (United States)

    Cruz, Adriana R.; Ramirez, Lady G.; Zuluaga, Ana V.; Pillay, Allan; Abreu, Christine; Valencia, Carlos A.; La Vake, Carson; Cervantes, Jorge L.; Dunham-Ems, Star; Cartun, Richard; Mavilio, Domenico; Radolf, Justin D.; Salazar, Juan C.

    2012-01-01

    Background The clinical syndrome associated with secondary syphilis (SS) reflects the propensity of Treponema pallidum (Tp) to escape immune recognition while simultaneously inducing inflammation. Methods To better understand the duality of immune evasion and immune recognition in human syphilis, herein we used a combination of flow cytometry, immunohistochemistry (IHC), and transcriptional profiling to study the immune response in the blood and skin of 27 HIV(-) SS patients in relation to spirochetal burdens. Ex vivo opsonophagocytosis assays using human syphilitic sera (HSS) were performed to model spirochete-monocyte/macrophage interactions in vivo. Results Despite the presence of low-level spirochetemia, as well as immunophenotypic changes suggestive of monocyte activation, we did not detect systemic cytokine production. SS subjects had substantial decreases in circulating DCs and in IFNγ-producing and cytotoxic NK-cells, along with an emergent CD56−/CD16+ NK-cell subset in blood. Skin lesions, which had visible Tp by IHC and substantial amounts of Tp-DNA, had large numbers of macrophages (CD68+), a relative increase in CD8+ T-cells over CD4+ T-cells and were enriched for CD56+ NK-cells. Skin lesions contained transcripts for cytokines (IFN-γ, TNF-α), chemokines (CCL2, CXCL10), macrophage and DC activation markers (CD40, CD86), Fc-mediated phagocytosis receptors (FcγRI, FcγR3), IFN-β and effector molecules associated with CD8 and NK-cell cytotoxic responses. While HSS promoted uptake of Tp in conjunction with monocyte activation, most spirochetes were not internalized. Conclusions Our findings support the importance of macrophage driven opsonophagocytosis and cell mediated immunity in treponemal clearance, while suggesting that the balance between phagocytic uptake and evasion is influenced by the relative burdens of bacteria in blood and skin and the presence of Tp subpopulations with differential capacities for binding opsonic antibodies. They also

  19. Prevalence of borreliosis, anaplasmosis, ehrlichiosis and Dirofilaria immitis in dogs and vectors in Voronezh Reserve (Russia).

    Science.gov (United States)

    Volgina, N S; Romashov, B V; Romashova, N B; Shtannikov, A V

    2013-12-01

    Most of the dogs studied for the prevalence of CVBD have previously received acaricidal and insecticidal treatments. In the present work, a very specific population of dogs (Group 1) that had never been treated against ticks and mosquitoes was studied. Moreover, the territory occupied by this population has also never been treated, because it is a protected area--Voronezh Natural Reserve. Canine patients from veterinary clinics (Group 2) that had been treated against VBD vectors were studied for comparison. Eighty-two dogs (Group 1) were enrolled in June, 2008. Blood samples were tested using the IDEXX SNAP(®) 4Dx(®) test. A specific heartworm antigen was detected in 12.2% samples. The seroprevalence for Anaplasma phagocytophilum was found to be 34.1%. The antibodies to Borrelia C6 peptide and to Ehrlichia canis were detected in 2.4% of the samples. Almost all dogs with infections had no clinical signs. Only 3 mixed-infected dogs showed non-specific clinical signs. During the tick season, 358 Ixodes ricinus were collected; the prevalence of Borrelia burgdorferi s.l. and Anaplasma phagocytophilum was 21.9% and 0.6%, respectively. Four hundred and forty dogs (Group 2) were studied for comparison. Antibodies to B. burgdorferi s.l. were detected only in one dog, seroprevalence for A. phagocytophilum represented 1.1%, no E. canis seropositive dogs were identified, and 8.2% dogs were found infected with Dirofilaria immitis. Fifty-six percent of dogs with dirofilariosis had clinical signs. All dogs with anaplasmosis showed specific clinical signs--fever, anemia, splenitis. Three dogs died within a few days. PMID:24054985

  20. Incorporating NDVI in a gravity model setting to describe spatio-temporal patterns of Lyme borreliosis incidence

    Science.gov (United States)

    Barrios, J. M.; Verstraeten, W. W.; Farifteh, J.; Maes, P.; Aerts, J. M.; Coppin, P.

    2012-04-01

    Lyme borreliosis (LB) is the most common tick-borne disease in Europe and incidence growth has been reported in several European countries during the last decade. LB is caused by the bacterium Borrelia burgdorferi and the main vector of this pathogen in Europe is the tick Ixodes ricinus. LB incidence and spatial spread is greatly dependent on environmental conditions impacting habitat, demography and trophic interactions of ticks and the wide range of organisms ticks parasite. The landscape configuration is also a major determinant of tick habitat conditions and -very important- of the fashion and intensity of human interaction with vegetated areas, i.e. human exposure to the pathogen. Hence, spatial notions as distance and adjacency between urban and vegetated environments are related to human exposure to tick bites and, thus, to risk. This work tested the adequacy of a gravity model setting to model the observed spatio-temporal pattern of LB as a function of location and size of urban and vegetated areas and the seasonal and annual change in the vegetation dynamics as expressed by MODIS NDVI. Opting for this approach implies an analogy with Newton's law of universal gravitation in which the attraction forces between two bodies are directly proportional to the bodies mass and inversely proportional to distance. Similar implementations have proven useful in fields like trade modeling, health care service planning, disease mapping among other. In our implementation, the size of human settlements and vegetated systems and the distance separating these landscape elements are considered the 'bodies'; and the 'attraction' between them is an indicator of exposure to pathogen. A novel element of this implementation is the incorporation of NDVI to account for the seasonal and annual variation in risk. The importance of incorporating this indicator of vegetation activity resides in the fact that alterations of LB incidence pattern observed the last decade have been ascribed

  1. Stage-specific global alterations in the transcriptomes of Lyme disease spirochetes during tick feeding and following mammalian host adaptation.

    Science.gov (United States)

    Iyer, Radha; Caimano, Melissa J; Luthra, Amit; Axline, David; Corona, Arianna; Iacobas, Dumitru A; Radolf, Justin D; Schwartz, Ira

    2015-02-01

    Borrelia burgdorferi, the agent of Lyme disease, is maintained in nature within an enzootic cycle involving a mammalian reservoir and an Ixodes sp. tick vector. The transmission, survival and pathogenic potential of B. burgdorferi depend on the bacterium's ability to modulate its transcriptome as it transits between vector and reservoir host. Herein, we employed an amplification-microarray approach to define the B. burgdorferi transcriptomes in fed larvae, fed nymphs and in mammalian host-adapted organisms cultivated in dialysis membrane chambers. The results show clearly that spirochetes exhibit unique expression profiles during each tick stage and during cultivation within the mammal; importantly, none of these profiles resembles that exhibited by in vitro grown organisms. Profound shifts in transcript levels were observed for genes encoding known or predicted lipoproteins as well as proteins involved in nutrient uptake, carbon utilization and lipid synthesis. Stage-specific expression patterns of chemotaxis-associated genes also were noted, suggesting that the composition and interactivities of the chemotaxis machinery components vary considerably in the feeding tick and mammal. The results as a whole make clear that environmental sensing by B. burgdorferi directly or indirectly drives an extensive and tightly integrated modulation of cell envelope constituents, chemotaxis/motility machinery, intermediary metabolism and cellular physiology. These findings provide the necessary transcriptional framework for delineating B. burgdorferi regulatory pathways throughout the enzootic cycle as well as defining the contribution(s) of individual genes to spirochete survival in nature and virulence in humans. PMID:25425211

  2. A possible role for inflammation in mediating apoptosis of oligodendrocytes as induced by the Lyme disease spirochete Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Ramesh Geeta

    2012-04-01

    Full Text Available Abstract Background Inflammation caused by the Lyme disease spirochete B. burgdorferi is an important factor in the pathogenesis of Lyme neuroborreliosis. Our central hypothesis is that B. burgdorferi can cause disease via the induction of inflammatory mediators such as cytokines and chemokines in glial and neuronal cells. Earlier we demonstrated that interaction of B. burgdorferi with brain parenchyma induces inflammatory mediators in glial cells as well as glial (oligodendrocyte and neuronal apoptosis using ex vivo and in vivo models of experimentation. Methods In this study we evaluated the ability of live B. burgdorferi to elicit inflammation in vitro in differentiated human MO3.13 oligodendrocytes and in differentiated primary human oligodendrocytes, by measuring the concentration of immune mediators in culture supernatants using Multiplex ELISA assays. Concomitant apoptosis was quantified in these cultures by the in situ terminal deoxynucleotidyl transferase mediated UTP nick end labeling (TUNEL assay and by quantifying active caspase-3 by flow cytometry. The above phenomena were also evaluated after 48 h of stimulation with B. burgdorferi in the presence and absence of various concentrations of the anti-inflammatory drug dexamethasone. Results B. burgdorferi induced enhanced levels of the cytokine IL-6 and the chemokines IL-8 and CCL2 in MO3.13 cells as compared to basal levels, and IL-8 and CCL2 in primary human oligodendrocytes, in a dose-dependent manner. These cultures also showed significantly elevated levels of apoptosis when compared with medium controls. Dexamethasone reduced both the levels of immune mediators and apoptosis, also in a manner that was dose dependent. Conclusions This finding supports our hypothesis that the inflammatory response elicited by the Lyme disease spirochete in glial cells contributes to neural cell damage. As oligodendrocytes are vital for the functioning and survival of neurons, the inflammation and

  3. Seroprevalence of canine dirofilariosis, granulocytic anaplasmosis and lyme borreliosis of public health importance in dogs from India’s North East

    Directory of Open Access Journals (Sweden)

    S. K. Borthakur

    2014-09-01

    Full Text Available Aim: Vector-borne infections namely dirofilariosis, ehrlichiosis, anaplasmosis and lyme borreliosis are being recognized as emerging and/or re-emerging problems in dogs and man due to rapid extension of zoogeographical ranges of many causative agents through international tourism and increase mobility of dogs at national and international level towards meeting the demand for companion animals in the present day society. Anticipating such situation, a serological study was conducted in dogs from North East India to estimate the prevalence of zoonotically important Dirofilaria immitis, Anaplasma phagocytophilum and Borrelia burgdorferi along with Ehrlichia canis. Materials and Methods: Serological study was carried out using enzyme immunoassay in commercial SNAP 4DX® test kit (Idexx Laboratories, USA. The study was conducted in 191 dogs comprising 82 pets, 57 stray and 52 working dogs owned by defence organizations. Results: The study revealed seroprevalence of mosquito-borne D. immitis (17.80%, tick-borne E. canis (22.51% and A. phagocytophilum (4.71% with an overall 41.88% prevalence of pathogens in single or co-infection. Serological evidence of tick-borne lyme borreliosis due to B. burgdorferi could not be established in dogs in the present study. Of the zoonotic species, highest prevalence of D. immitis was found in the stray dogs (22.80% and that of A. phagocytophilum in pet dogs (6.09%. Conclusion: The results of the present serological study serve as baseline information on the prevalence of A. phagocytophilum in dogs reported for the first time in India and reaffirmation on the high prevalence of D. immitis and E. canis in the North East India.

  4. Ultrastructural analysis of volutin-acidocalciumosomes formation in some species of bacteria, spirochetes, yeast and protozoa during morphogenesis and under environment different factors action

    International Nuclear Information System (INIS)

    Ultrastructure organization of volutin granules in some species of bacteria, spirochetes, yeast and protozoa cellular architecture was studied during morphogenesis and under environment different factors action leading to pathological changes. As the result of complex electron microscopic studies of morphogenesis in some species of prokaryotes and eukaryotic organisms the formation of new structures of volutin-acidocal-ciumosomes has been established within cell cytoplasm. In addition, under the ionizing roentgen and irradiation as well as some antibiotics action morphometric changes and changes in optical properties were also shown. Electron microscopic identification of volutin granules changes in structural organization in bacteria, spirochetes, yeast and protozoa might serve as appropriate express-method for visual evaluation of damage and reparation processes during environment

  5. Isolation and Characterization of FecA- and FeoB-Mediated Iron Acquisition Systems of the Spirochete Leptospira biflexa by Random Insertional Mutagenesis

    OpenAIRE

    Louvel, Hélène; Saint Girons, Isabelle; Picardeau, Mathieu

    2005-01-01

    The specific mechanisms by which Leptospira spp. acquire iron from their ecological niches are unknown. A major factor contributing to our ignorance of spirochetal biology is the lack of methods for genetic analysis of these organisms. In this study, we have developed a system for random transposon mutagenesis of Leptospira biflexa using a mariner transposon, Himar1. To demonstrate the validity of Himar1 in vivo transposon mutagenesis in L. biflexa, a screen of mutants for clones impaired in ...

  6. Invasion of Oral and Aortic Tissues by Oral Spirochete Treponema denticola in ApoE−/− Mice Causally Links Periodontal Disease and Atherosclerosis

    OpenAIRE

    Chukkapalli, Sasanka S.; Mercedes F Rivera; Irina M Velsko; Lee, Ju-Youn; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R.; Lucas, Alexandra R.; Kesavalu, Lakshmyya

    2014-01-01

    Treponema denticola is a predominantly subgingival oral spirochete closely associated with periodontal disease and has been detected in atherosclerosis. This study was designed to evaluate causative links between periodontal disease induced by chronic oral T. denticola infection and atherosclerosis in hyperlipidemic ApoE−/− mice. ApoE−/− mice (n = 24) were orally infected with T. denticola ATCC 35404 and were euthanized after 12 and 24 weeks. T. denticola genomic DNA was detected in oral plaq...

  7. Intravital Imaging of Vascular Transmigration by the Lyme Spirochete: Requirement for the Integrin Binding Residues of the B. burgdorferi P66 Protein.

    Directory of Open Access Journals (Sweden)

    Devender Kumar

    2015-12-01

    Full Text Available Vascular extravasation, a key step in systemic infection by hematogenous microbial pathogens, is poorly understood, but has been postulated to encompass features similar to vascular transmigration by leukocytes. The Lyme disease spirochete can cause a variety of clinical manifestations, including arthritis, upon hematogenous dissemination. This pathogen encodes numerous surface adhesive proteins (adhesins that may promote extravasation, but none have yet been implicated in this process. In this work we report the novel use of intravital microscopy of the peripheral knee vasculature to study transmigration of the Lyme spirochete in living Cd1d-/-mice. In the absence of iNKT cells, major immune modulators in the mouse joint, spirochetes that have extravasated into joint-proximal tissue remain in the local milieu and can be enumerated accurately. We show that BBK32, a fibronectin and glycosaminoglycan adhesin of B. burgdorferi involved in early steps of endothelial adhesion, is not required for extravasation from the peripheral knee vasculature. In contrast, almost no transmigration occurs in the absence of P66, an outer membrane protein that has porin and integrin adhesin functions. Importantly, P66 mutants specifically defective in integrin binding were incapable of promoting extravasation. P66 itself does not promote detectable microvascular interactions, suggesting that vascular adhesion of B. burgdorferi mediated by other adhesins, sets the stage for P66-integrin interactions leading to transmigration. Although integrin-binding proteins with diverse functions are encoded by a variety of bacterial pathogens, P66 is the first to have a documented and direct role in vascular transmigration. The emerging picture of vascular escape by the Lyme spirochete shows similarities, but distinct differences from leukocyte transmigration.

  8. Borrelia Spirochetes Upregulate Release and Activation of Matrix Metalloproteinase Gelatinase B (MMP-9) and Collagenase 1 (MMP-1) in Human Cells

    OpenAIRE

    Gebbia, Joseph A.; Coleman, James L.; Benach, Jorge L

    2001-01-01

    Borrelia burgdorferi, the spirochetal agent of Lyme disease, stimulated human peripheral blood monocytes to release pro-matrix metalloproteinase-9 (gelatinase B; pro-MMP-9) and active matrix metalloproteinase-1 (collagenase-1; MMP-1). Human neutrophils also released pro-MMP-9 and a 130-kDa protein with gelatinolytic activity in response to live B. burgdorferi. In addition, U937 cells and human keratinocyte cells were also stimulated to release pro-MMP-9 under the same conditions. However, hum...

  9. Epidemiology of Lyme borreliosis

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk

    Basel : Karger, 2009 - (Lipsker, D.; Jaulhac, B., B.), s. 31-50 ISBN 978-3-8055-9114-0. - (Current Problems in Dermatology. 37) Grant ostatní: 6th Framework Programme(XE) GOCE-2003-010284 EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : Borrelia burgdorferi sensu lato * infectious disease s * natural focality of disease s * incidence rates * environmental effects Subject RIV: FN - Epidemiology, Contagious Disease s ; Clinical Immunology

  10. Host cell heparan sulfate glycosaminoglycans are ligands for OspF-related proteins of the Lyme disease spirochete.

    Science.gov (United States)

    Lin, Yi-Pin; Bhowmick, Rudra; Coburn, Jenifer; Leong, John M

    2015-10-01

    Borrelia burgdorferi, the agent of Lyme disease, spreads from the site of the tick bite to tissues such as heart, joints and the nervous tissues. Host glycosaminoglycans, highly modified repeating disaccharides that are present on cell surfaces and in extracellular matrix, are common targets of microbial pathogens during tissue colonization. While several dermatan sulfate-binding B. burgdorferi adhesins have been identified, B. burgdorferi adhesins documented to promote spirochetal binding to heparan sulfate have not yet been identified. OspEF-related proteins (Erps), a large family of plasmid-encoded surface lipoproteins that are produced in the mammalian host, can be divided into the OspF-related, OspEF-leader peptide (Elp) and OspE-related subfamilies. We show here that a member of the OspF-related subfamily, ErpG, binds to heparan sulfate and when produced on the surface of an otherwise non-adherent B. burgdorferi strain, ErpG promotes heparan sulfate-mediated bacterial attachment to the glial but not the endothelial, synovial or respiratory epithelial cells. Six other OspF-related proteins were capable of binding heparan sulfate, whereas representative OspE-related and Elp proteins lacked this activity. These results indicate that OspF-related proteins are heparan sulfate-binding adhesins, at least one of which promotes bacterial attachment to glial cells. PMID:25864455

  11. Detection of Borrelia burgdorferi Sensu Stricto ospC Alleles Associated with Human Lyme Borreliosis Worldwide in Non-Human-Biting Tick Ixodes affinis and Rodent Hosts in Southeastern United States

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Hönig, Václav; Mallátová, N.; Krbková, L.; Mikulášek, P.; Fedorovova, N.; Belfiore, N. M.; Grubhoffer, Libor; Lane, R. S.; Oliver, J. H., Jr.

    2013-01-01

    Roč. 79, č. 5 (2013), s. 1444-1453. ISSN 0099-2240 Grant ostatní: NIH(US) R37AI-24899 Institutional support: RVO:60077344 Keywords : North America * disease spirochete * genetic diversity * Europe * transmission Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.952, year: 2013

  12. Prevalence of the Lyme Disease Spirochete, Borrelia burgdorferi, in Blacklegged Ticks, Ixodes scapularis at Hamilton-Wentworth, Ontario.

    Science.gov (United States)

    Scott, John D; Anderson, John F; Durden, Lance A; Smith, Morgan L; Manord, Jodi M; Clark, Kerry L

    2016-01-01

    Lyme disease has emerged as a major health concern in Canada, where the etiological agent, Borrelia burgdorferi sensu lato (s.l.), a spirochetal bacterium, is typically spread by the bite of certain ticks. This study explores the presence of B. burgdorferi s.l. in blacklegged ticks, Ixodes scapularis, collected at Dundas, Ontario (a locality within the region of Hamilton-Wentworth). Using passive surveillance, veterinarians and pet groomers were asked to collect blacklegged ticks from dogs and cats with no history of travel. Additionally, I. scapularis specimens were submitted from local residents and collected by flagging. Overall, 12 (41%) of 29 blacklegged ticks were infected with B. burgdorferi s.l. Using polymerase chain reaction (PCR) and DNA sequencing, two borrelial amplicons were characterized as B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. Notably, three different vertebrate hosts each had two engorged I. scapularis females removed on the same day and, likewise, one cat had three repeat occurrences of this tick species. These multiple infestations suggest that a population of I. scapularis may be established in this area. The local public health unit has been underreporting the presence of B. burgdorferi s.l.-infected I. scapularis in the area encompassing Dundas. Our findings raise concerns about the need to erect tick warning signs in parkland areas. Veterinarians, medical professionals, public health officials, and the general public must be vigilant that Lyme disease-carrying blacklegged ticks pose a public health risk in the Dundas area and the surrounding Hamilton-Wentworth region. PMID:27226771

  13. Prevalence of the Lyme Disease Spirochete, Borrelia burgdorferi, in Blacklegged Ticks, Ixodes scapularis at Hamilton-Wentworth, Ontario

    Science.gov (United States)

    Scott, John D.; Anderson, John F.; Durden, Lance A.; Smith, Morgan L.; Manord, Jodi M.; Clark, Kerry L.

    2016-01-01

    Lyme disease has emerged as a major health concern in Canada, where the etiological agent, Borrelia burgdorferi sensu lato (s.l.), a spirochetal bacterium, is typically spread by the bite of certain ticks. This study explores the presence of B. burgdorferi s.l. in blacklegged ticks, Ixodes scapularis, collected at Dundas, Ontario (a locality within the region of Hamilton-Wentworth). Using passive surveillance, veterinarians and pet groomers were asked to collect blacklegged ticks from dogs and cats with no history of travel. Additionally, I. scapularis specimens were submitted from local residents and collected by flagging. Overall, 12 (41%) of 29 blacklegged ticks were infected with B. burgdorferi s.l. Using polymerase chain reaction (PCR) and DNA sequencing, two borrelial amplicons were characterized as B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. Notably, three different vertebrate hosts each had two engorged I. scapularis females removed on the same day and, likewise, one cat had three repeat occurrences of this tick species. These multiple infestations suggest that a population of I. scapularis may be established in this area. The local public health unit has been underreporting the presence of B. burgdorferi s.l.-infected I. scapularis in the area encompassing Dundas. Our findings raise concerns about the need to erect tick warning signs in parkland areas. Veterinarians, medical professionals, public health officials, and the general public must be vigilant that Lyme disease-carrying blacklegged ticks pose a public health risk in the Dundas area and the surrounding Hamilton-Wentworth region. PMID:27226771

  14. HrpA, an RNA Helicase Involved in RNA Processing, Is Required for Mouse Infectivity and Tick Transmission of the Lyme Disease Spirochete

    Science.gov (United States)

    Salman-Dilgimen, Aydan; Hardy, Pierre-Olivier; Radolf, Justin D.; Caimano, Melissa J.; Chaconas, George

    2013-01-01

    The Lyme disease spirochete Borrelia burgdorferi must differentially express genes and proteins in order to survive in and transit between its tick vector and vertebrate reservoir. The putative DEAH-box RNA helicase, HrpA, has been recently identified as an addition to the spirochete's global regulatory machinery; using proteomic methods, we demonstrated that HrpA modulates the expression of at least 180 proteins. Although most bacteria encode an HrpA helicase, RNA helicase activity has never been demonstrated for HrpAs and the literature contains little information on the contribution of this protein to bacterial physiology or pathogenicity. In this work, we report that B. burgdorferi HrpA has RNA-stimulated ATPase activity and RNA helicase activity and that this enzyme is essential for both mammalian infectivity by syringe inoculation and tick transmission. Reduced infectivity of strains carrying mutations in the ATPase and RNA binding motif mutants suggests that full virulence expression requires both ATPase and coupled helicase activity. Microarray profiling revealed changes in RNA levels of two-fold, or less in an hrpA mutant versus wild-type, suggesting that the enzyme functions largely or exclusively at the post-transcriptional level. In this regard, northern blot analysis of selected gene products highly regulated by HrpA (bb0603 [p66], bba74, bb0241 [glpK], bb0242 and bb0243 [glpA]) suggests a role for HrpA in the processing and translation of transcripts. In addition to being the first demonstration of RNA helicase activity for a bacterial HrpA, our data indicate that the post-transcriptional regulatory functions of this enzyme are essential for maintenance of the Lyme disease spirochete's enzootic cycle. PMID:24367266

  15. Differential Role of Passerine Birds in Distribution of Borrelia Spirochetes, Based on Data from Ticks Collected from Birds during the Postbreeding Migration Period in Central Europe▿

    OpenAIRE

    Dubska, Lenka; Literak, Ivan; Kocianova, Elena; Taragelova, Veronika; Sychra, Oldrich

    2008-01-01

    Borrelia spirochetes in bird-feeding ticks were studied in the Czech Republic. During the postbreeding period (July to September 2005), 1,080 passerine birds infested by 2,240 Ixodes ricinus subadult ticks were examined. Borrelia garinii was detected in 22.2% of the ticks, Borrelia valaisiana was detected in 12.8% of the ticks, Borrelia afzelii was detected in 1.6% of the ticks, and Borrelia burgdorferi sensu stricto was detected in 0.3% of the ticks. After analysis of infections in which the...

  16. What ticks do under your skin: two-photon intravital imaging of Ixodes scapularis feeding in the presence of the lyme disease spirochete.

    Science.gov (United States)

    Bockenstedt, Linda K; Gonzalez, David; Mao, Jialing; Li, Ming; Belperron, Alexia A; Haberman, Ann

    2014-03-01

    Lyme disease, due to infection with the Ixodes-tick transmitted spirochete Borrelia burgdorferi, is the most common tick-transmitted disease in the northern hemisphere. Our understanding of the tick-pathogen-vertebrate host interactions that sustain an enzootic cycle for B. burgdorferi is incomplete. In this article, we describe a method for imaging the feeding of Ixodes scapularis nymphs in real-time using two-photon intravital microscopy and show how this technology can be applied to view the response of Lyme borrelia in the skin of an infected host to tick feeding. PMID:24600332

  17. Stage-Specific Global Alterations in the Transcriptomes of Lyme Disease Spirochetes During Tick Feeding and Following Mammalian Host-Adaptation

    Science.gov (United States)

    Iyer, Radha; Caimano, Melissa J.; Luthra, Amit; Axline, David; Corona, Arianna; Iacobas, Dumitru A.; Radolf, Justin D.; Schwartz, Ira

    2015-01-01

    Borrelia burgdorferi, the agent of Lyme disease, is maintained in nature within an enzootic cycle involving a mammalian reservoir and an Ixodes sp. tick vector. The transmission, survival and pathogenic potential of B. burgdorferi depend on the bacterium’s ability to modulate its transcriptome as it transits between vector and reservoir host. Herein, we employed an amplification-microarray approach to define the B. burgdorferi transcriptomes in fed larvae, fed nymphs and in mammalian host-adapted organisms cultivated in dialysis membrane chambers. The results show clearly that spirochetes exhibit unique expression profiles during each tick stage and during cultivation within the mammal; importantly, none of these profiles resembles that exhibited by in vitro-grown organisms. Profound shifts in transcript levels were observed for genes encoding known or predicted lipoproteins as well as proteins involved in nutrient uptake, carbon utilization and lipid synthesis. Stage-specific expression patterns of chemotaxis-associated genes also were noted, suggesting that the composition and interactivities of the chemotaxis machinery components vary considerably in the feeding tick and mammal. The results as a whole make clear that environmental sensing by B. burgdorferi directly or indirectly drives an extensive and tightly integrated modulation of cell envelope constituents, chemotaxis/motility machinery, intermediary metabolism and cellular physiology. These findings provide the necessary transcriptional framework for delineating B. burgdorferi regulatory pathways throughout the enzootic cycle as well as defining the contribution(s) of individual genes to spirochete survival in nature and virulence in humans. PMID:25425211

  18. Use of T7 RNA polymerase to direct expression of outer Surface Protein A (OspA) from the Lyme disease Spirochete, Borrelia burgdorferi

    Science.gov (United States)

    Dunn, John J.; Lade, Barbara N.

    1991-01-01

    The OspA gene from a North American strain of the Lyme disease Spirochete, Borrelia burgdorferi, was cloned under the control of transciption and translation signals from bacteriophage T7. Full-length OspA protein, a 273 amino acid (31kD) lipoprotein, is expressed poorly in Escherichia coli and is associated with the insoluble membrane fraction. In contrast, a truncated form of OspA lacking the amino-terminal signal sequence which normally would direct localization of the protein to the outer membrane is expressed at very high levels (less than or equal to 100 mg/liter) and is soluble. The truncated protein was purified to homogeneity and is being tested to see if it will be useful as an immunogen in a vaccine against Lyme disease. Circular dichroism and fluorescence spectroscopy was used to characterize the secondary structure and study conformational changes in the protein. Studies underway with other surface proteins from B burgdorferi and a related spirochete, B. hermsii, which causes relapsing fever, leads us to conclude that a strategy similar to that used to express the truncated OspA can provide a facile method for producing variations of Borrelia lipoproteins which are highly expressed in E. coli and soluble without exposure to detergents.

  19. Assessment of antibodies against surface and outer membrane proteins of Anaplasma phagocytophilum in Lyme borreliosis and tick-borne encephalitis paediatric patients.

    Science.gov (United States)

    Krbková, L; Homola, L; Hlaváčová, A; Mikolášek, P; Bednářová, J; Čermáková, Z

    2016-09-01

    To examine evidence of positive antibodies against immunogenic proteins of Anaplasma phagocytophilum in patients with other tick-borne infections and to diagnose possible co-infections, 412 serum specimens were tested by immunoblotting using three specific Anaplasma antigens: surface proteins p44 and Asp62 and outer membrane protein A (OmpA). In total, 284 serum samples from children with Lyme borreliosis and 12 serum samples from children with tick-borne encephalitis were tested. Sera from patients with viral aseptic meningitis (n = 47) and from blood donors (n = 69) were used as controls. Among all serum specimens from patients with tick-borne infections submitted for this study, six samples (2·0%) showed positive IgM reactions and seven samples (2·4%) were IgG positive for A. phagocytophilum by immunoblot. Borderline reactivity was found in 30 samples (10·14%) for IgM and 36 samples (12·2%) for IgG. The difference between patients and blood donors was statistically significant for IgM (P = 0·006) and for IgG (P = 0·0007) antibodies. A statistically significant result was obtained for IgG (P = 0·02) but not for IgM between patients and children with aseptic meningitis. Immunoblot using three specific antigens provides novel information about the positivity of antibodies to A. phagocytophilum in children with other tick-borne infections. Taking into account clinical and laboratory findings of children despite antibody positivity, no case of human granulocytic anaplasmosis was demonstrated. PMID:27180603

  20. Concordance of four commercial enzyme immunoassay and three immunoblot formats for the detection of Lyme borreliosis antibodies in human serum: the two-tier approach remains.

    Science.gov (United States)

    Dickeson, David J; Chen, Sharon C-A; Sintchenko, Vitali G

    2016-04-01

    Serological tests show considerable variation in their ability to correctly diagnose Lyme borreliosis (LB). This study compared four commercially available screening enzyme immunoassays (EIA) for the detection of LB IgG using either whole cell lysate (WCL) antigens, purified proteins or recombinant antigens with the second-tier whole cell sonicate (WCS) western immunoblots or recombinant antigen line blots. A consensus between three EIA results from 222 patient sera was designated as a point of comparison for each method which gave 66 positive and 156 negative results. The positive predictive values (PPV) of WCL EIA were 40% for the MarDx Diagnostics Borrelia burgdorferi EIA 'combined' IgG and IgM (Trinity Biotech) and 55% for the EUROIMMUN plus VlsE IgG. These were significantly lower PPVs than that produced by the recombinant antigen-based EIA NovaLisa Borrelia burgdorferi IgG-ELISA (NovaTec Immunodiagnostica) and the EUROIMMUN Anti-Borrelia Select ELISA IgG (90% and 100%, respectively; p = 0.02). The WCS western immunoblot using B. burgdorferi and B. afzelii separately showed a high PPV of 91% but its positive agreement with consensus EIA result was only 65%. Another WCL western immunoblot with purified extracts of Osp C and VlsE, the Trinity Biotech EU Lyme + VlsE IgG Western Blot had a PPV of 92% while the recombinant line blot from EUROIMMUN, the Anti-Borrelia (IgG) EUROLINE-RN-AT, demonstrated a significantly reduced PPV of 70% with some non-specific reactions in sera containing antibodies to Leptospira species, Helicobacter pylori and Treponema pallidum. The use of recombinant antigens in EIA for LB IgG screening significantly improves the predictive values of serological results above those of WCL antigen EIA. Second tier WCS western immunoblots offer high PPVs, especially with added specific purified proteins, more so than in one recombinant line blot. PMID:27020501

  1. The Epidemiology and Geographic Distribution of Relapsing Fever Borreliosis in West and North Africa, with a Review of the Ornithodoros erraticus Complex (Acari: Ixodida)

    Science.gov (United States)

    Trape, Jean-François; Diatta, Georges; Arnathau, Céline; Bitam, Idir; Sarih, M’hammed; Belghyti, Driss; Bouattour, Ali; Elguero, Eric; Vial, Laurence; Mané, Youssouph; Baldé, Cellou; Pugnolle, Franck; Chauvancy, Gilles; Mahé, Gil; Granjon, Laurent; Duplantier, Jean-Marc

    2013-01-01

    Background Relapsing fever is the most frequent bacterial disease in Africa. Four main vector / pathogen complexes are classically recognized, with the louse Pediculus humanus acting as vector for B. recurrentis and the soft ticks Ornithodoros sonrai, O. erraticus and O. moubata acting as vectors for Borrelia crocidurae, B. hispanica and B. duttonii, respectively. Our aim was to investigate the epidemiology of the disease in West, North and Central Africa. Methods And Findings From 2002 to 2012, we conducted field surveys in 17 African countries and in Spain. We investigated the occurrence of Ornithodoros ticks in rodent burrows in 282 study sites. We collected 1,629 small mammals that may act as reservoir for Borrelia infections. Using molecular methods we studied genetic diversity among Ornithodoros ticks and Borrelia infections in ticks and small mammals. Of 9,870 burrows investigated, 1,196 (12.1%) were inhabited by Ornithodoros ticks. In West Africa, the southern and eastern limits of the vectors and Borrelia infections in ticks and small mammals were 13°N and 01°E, respectively. Molecular studies revealed the occurrence of nine different Ornithodoros species, including five species new for science, with six of them harboring Borrelia infections. Only B. crocidurae was found in West Africa and three Borrelia species were identified in North Africa: B. crocidurae, B. hispanica, and B. merionesi. Conclusions Borrelia Spirochetes responsible for relapsing fever in humans are highly prevalent both in Ornithodoros ticks and small mammals in North and West Africa but Ornithodoros ticks seem absent south of 13°N and small mammals are not infected in these regions. The number of Ornithodoros species acting as vector of relapsing fever is much higher than previously known. PMID:24223812

  2. Periplasmic Flagellar Export Apparatus Protein, FliH, Is Involved in Post-Transcriptional Regulation of FlaB, Motility and Virulence of the Relapsing Fever Spirochete Borrelia hermsii

    Science.gov (United States)

    Guyard, Cyril; Raffel, Sandra J.; Schrumpf, Merry E.; Dahlstrom, Eric; Sturdevant, Daniel; Ricklefs, Stacy M.; Martens, Craig; Hayes, Stanley F.; Fischer, Elizabeth R.; Hansen, Bryan T.; Porcella, Stephen F.; Schwan, Tom G.

    2013-01-01

    Spirochetes are bacteria characterized in part by rotating periplasmic flagella that impart their helical or flat-wave morphology and motility. While most other bacteria rely on a transcriptional cascade to regulate the expression of motility genes, spirochetes employ post-transcriptional mechanism(s) that are only partially known. In the present study, we characterize a spontaneous non-motile mutant of the relapsing fever spirochete Borrelia hermsii that was straight, non-motile and deficient in periplasmic flagella. We used next generation DNA sequencing of the mutant’s genome, which when compared to the wild-type genome identified a 142 bp deletion in the chromosomal gene encoding the flagellar export apparatus protein FliH. Immunoblot and transcription analyses showed that the mutant phenotype was linked to the posttranscriptional deficiency in the synthesis of the major periplasmic flagellar filament core protein FlaB. Despite the lack of FlaB, the amount of FlaA produced by the fliH mutant was similar to the wild-type level. The turnover of the residual pool of FlaB produced by the fliH mutant was comparable to the wild-type spirochete. The non-motile mutant was not infectious in mice and its inoculation did not induce an antibody response. Trans-complementation of the mutant with an intact fliH gene restored the synthesis of FlaB, a normal morphology, motility and infectivity in mice. Therefore, we propose that the flagellar export apparatus protein regulates motility of B. hermsii at the post-transcriptional level by influencing the synthesis of FlaB. PMID:24009690

  3. Periplasmic flagellar export apparatus protein, FliH, is involved in post-transcriptional regulation of FlaB, motility and virulence of the relapsing fever spirochete Borrelia hermsii.

    Directory of Open Access Journals (Sweden)

    Cyril Guyard

    Full Text Available Spirochetes are bacteria characterized in part by rotating periplasmic flagella that impart their helical or flat-wave morphology and motility. While most other bacteria rely on a transcriptional cascade to regulate the expression of motility genes, spirochetes employ post-transcriptional mechanism(s that are only partially known. In the present study, we characterize a spontaneous non-motile mutant of the relapsing fever spirochete Borrelia hermsii that was straight, non-motile and deficient in periplasmic flagella. We used next generation DNA sequencing of the mutant's genome, which when compared to the wild-type genome identified a 142 bp deletion in the chromosomal gene encoding the flagellar export apparatus protein FliH. Immunoblot and transcription analyses showed that the mutant phenotype was linked to the posttranscriptional deficiency in the synthesis of the major periplasmic flagellar filament core protein FlaB. Despite the lack of FlaB, the amount of FlaA produced by the fliH mutant was similar to the wild-type level. The turnover of the residual pool of FlaB produced by the fliH mutant was comparable to the wild-type spirochete. The non-motile mutant was not infectious in mice and its inoculation did not induce an antibody response. Trans-complementation of the mutant with an intact fliH gene restored the synthesis of FlaB, a normal morphology, motility and infectivity in mice. Therefore, we propose that the flagellar export apparatus protein regulates motility of B. hermsii at the post-transcriptional level by influencing the synthesis of FlaB.

  4. Study of the climatic change impact on vector-borne diseases in West Africa: the case of tick-borne borreliosis and malaria; Etude de l'impact du changement climatique sur les maladies a transmission vectorielle en Afrique de l'Ouest: le cas de la borreliose a tiques et du paludisme

    Energy Technology Data Exchange (ETDEWEB)

    Trape, J.F

    2005-04-15

    Malaria and tick-borne borreliosis are the two first causes of morbidity due to vector-borne diseases in a large part of Sudan-sahelian West Africa. They are also the two tropical diseases which have been the most affected by climatic change in recent years. In the case of tick-borne borreliosis it has been shown in Senegal that the persistence of drought since the years 70 has been associated with a considerable extension of the geographic range of diseases and the vector tick A-sonrai, a species that was in the past limited to the Sahara and Sahel. In the case of malaria, drought has strongly reduced in these same regions of Africa the distribution, abundance and infection rate of Anopheline mosquitoes, but without any significant reduction of the burden of malaria for most populations concerned. The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs only explain part of this phenomenon. (A.L.B.)

  5. Hispathologic aspects of Lyme Borreliosis.

    OpenAIRE

    Koning, Johannes de

    1994-01-01

    As a result of the recent interest in Lyme disease a large number of papers has been published on its different aspects. The purpose of this thesis is to present a comprehensive study of the most important histopathological manifestations based on the experience obtained during the last 11 years. In the first years, serology was not yet available in our laboratory, the histopathology and demonstration of spirochaetes in tissue were a part of the cliagnostic tools; till to day the recognition ...

  6. Hispathologic aspects of Lyme Borreliosis.

    NARCIS (Netherlands)

    Koning, Johannes de

    1994-01-01

    As a result of the recent interest in Lyme disease a large number of papers has been published on its different aspects. The purpose of this thesis is to present a comprehensive study of the most important histopathological manifestations based on the experience obtained during the last 11 years. In

  7. Neutrophil Extracellular Traps Entrap and Kill Borrelia burgdorferi Sensu Stricto Spirochetes and Are Not Affected by Ixodes ricinus Tick Saliva

    Czech Academy of Sciences Publication Activity Database

    Menten-Dedoyart, C.; Faccinetto, C.; Golovchenko, Maryna; Dupiereux, I.; Van Lerberghe, P.B.; Dubois, S.; Desmet, C.; Elmoualij, B.; Baron, F.; Rudenko, Natalia; Oury, C.; Heinen, E.; Couvreur, B.

    2012-01-01

    Roč. 189, č. 11 (2012), s. 5393-5401. ISSN 0022-1767 Institutional support: RVO:60077344 Keywords : GROUP-A STREPTOCOCCUS * IMMUNE-RESPONSE * PROTEIN * ESCAPE * INNATE * DEOXYRIBONUCLEASE * EXPRESSION * ALLOWS Subject RIV: EC - Immunology Impact factor: 5.520, year: 2012 http://www.jimmunol.org/content/189/11/5393

  8. Invasion of oral and aortic tissues by oral spirochete Treponema denticola in ApoE(-/-) mice causally links periodontal disease and atherosclerosis.

    Science.gov (United States)

    Chukkapalli, Sasanka S; Rivera, Mercedes F; Velsko, Irina M; Lee, Ju-Youn; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R; Lucas, Alexandra R; Kesavalu, Lakshmyya

    2014-05-01

    Treponema denticola is a predominantly subgingival oral spirochete closely associated with periodontal disease and has been detected in atherosclerosis. This study was designed to evaluate causative links between periodontal disease induced by chronic oral T. denticola infection and atherosclerosis in hyperlipidemic ApoE(-/-) mice. ApoE(-/-) mice (n = 24) were orally infected with T. denticola ATCC 35404 and were euthanized after 12 and 24 weeks. T. denticola genomic DNA was detected in oral plaque samples, indicating colonization of the oral cavity. Infection elicited significantly (P = 0.0172) higher IgG antibody levels and enhanced intrabony defects than sham infection. T. denticola-infected mice had higher levels of horizontal alveolar bone resorption than sham-infected mice and an associated significant increase in aortic plaque area (P ≤ 0.05). Increased atherosclerotic plaque correlated with reduced serum nitric oxide (NO) levels and increased serum-oxidized low-density lipoprotein (LDL) levels compared to those of sham-infected mice. T. denticola infection altered the expression of genes known to be involved in atherosclerotic development, including the leukocyte/endothelial cell adhesion gene (Thbs4), the connective tissue growth factor gene (Ctgf), and the selectin-E gene (Sele). Fluorescent in situ hybridization (FISH) revealed T. denticola clusters in both gingival and aortic tissue of infected mice. This is the first study examining the potential causative role of chronic T. denticola periodontal infection and vascular atherosclerosis in vivo in hyperlipidemic ApoE(-/-) mice. T. denticola is closely associated with periodontal disease and the rapid progression of atheroma in ApoE(-/-) mice. These studies confirm a causal link for active oral T. denticola infection with both atheroma and periodontal disease. PMID:24566627

  9. Minimal-Change Disease Secondary to Borrelia burgdorferi Infection

    OpenAIRE

    Ewa Kwiatkowska; Edyta Gołembiewska; Kazimierz Ciechanowski; Karolina Kędzierska

    2012-01-01

    Lyme borreliosis is a chronic illness caused by tick-transmitted spirochete Borrelia burgdorferi. Borreliosis can be extremely threatening if it is not diagnosed and treated in early stages. Kidneys are not typically involved in the disease. However, in infected dogs, Lyme nephritis is present in 5–10% of cases. It is associated with rapidly progressing renal failure. Histopathological examination shows mesangial proliferative glomerulonephritis with diffuse tubular necrosis, (Dambach et al. ...

  10. New insights into Lyme disease

    OpenAIRE

    Peacock, Brandon N.; Gherezghiher, Teshome B.; Hilario, Jennifer D.; Kellermann, Gottfried H.

    2015-01-01

    Lyme borreliosis is transmitted through the bite of a tick that is infected by the bacterial spirochete Borrelia burgdorferi. Clinical manifestation of the disease can lead to heart conditions, neurological disorders, and inflammatory disorders. Oxidative stress has been implicated in the pathogenesis of many human diseases. The aim of this study was to investigate the mechanisms of oxidative stress and intracellular communication in Lyme borreliosis patients. Mitochondrial superoxide and cyt...

  11. Superoxide reductase from the syphilis spirochete Treponema pallidum: crystallization and structure determination using soft X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Silva, Teresa; Trincão, José; Carvalho, Ana L.; Bonifácio, Cecília; Auchère, Françoise; Moura, Isabel; Moura, José J. G.; Romão, Maria J., E-mail: mromao@dq.fct.unl.pt [REQUIMTE Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2005-11-01

    Superoxide reductase is a non-haem iron-containing protein involved in resistance to oxidative stress. The oxidized form of the protein has been crystallized and its three-dimensional structure solved. A highly redundant X-ray diffraction data set was collected on a rotating-anode generator using Cu Kα X-ray radiation. Four Fe atoms were located in the asymmetric unit corresponding to four protein molecules arranged as a dimer of homodimers. Superoxide reductase is a 14 kDa metalloprotein containing a catalytic non-haem iron centre [Fe(His){sub 4}Cys]. It is involved in defence mechanisms against oxygen toxicity, scavenging superoxide radicals from the cell. The oxidized form of Treponema pallidum superoxide reductase was crystallized in the presence of polyethylene glycol and magnesium chloride. Two crystal forms were obtained depending on the oxidizing agents used after purification: crystals grown in the presence of K{sub 3}Fe(CN){sub 6} belonged to space group P2{sub 1} (unit-cell parameters a = 60.3, b = 59.9, c = 64.8 Å, β = 106.9°) and diffracted beyond 1.60 Å resolution, while crystals grown in the presence of Na{sub 2}IrCl{sub 6} belonged to space group C2 (a = 119.4, b = 60.1, c = 65.6 Å, β = 104.9°) and diffracted beyond 1.55 Å. A highly redundant X-ray diffraction data set from the C2 crystal form collected on a copper rotating-anode generator (λ = 1.542 Å) clearly defined the positions of the four Fe atoms present in the asymmetric unit by SAD methods. A MAD experiment at the iron absorption edge confirmed the positions of the previously determined iron sites and provided better phases for model building and refinement. Molecular replacement using the P2{sub 1} data set was successful using a preliminary trace as a search model. A similar arrangement of the four protein molecules could be observed.

  12. Superoxide reductase from the syphilis spirochete Treponema pallidum: crystallization and structure determination using soft X-rays

    International Nuclear Information System (INIS)

    Superoxide reductase is a non-haem iron-containing protein involved in resistance to oxidative stress. The oxidized form of the protein has been crystallized and its three-dimensional structure solved. A highly redundant X-ray diffraction data set was collected on a rotating-anode generator using Cu Kα X-ray radiation. Four Fe atoms were located in the asymmetric unit corresponding to four protein molecules arranged as a dimer of homodimers. Superoxide reductase is a 14 kDa metalloprotein containing a catalytic non-haem iron centre [Fe(His)4Cys]. It is involved in defence mechanisms against oxygen toxicity, scavenging superoxide radicals from the cell. The oxidized form of Treponema pallidum superoxide reductase was crystallized in the presence of polyethylene glycol and magnesium chloride. Two crystal forms were obtained depending on the oxidizing agents used after purification: crystals grown in the presence of K3Fe(CN)6 belonged to space group P21 (unit-cell parameters a = 60.3, b = 59.9, c = 64.8 Å, β = 106.9°) and diffracted beyond 1.60 Å resolution, while crystals grown in the presence of Na2IrCl6 belonged to space group C2 (a = 119.4, b = 60.1, c = 65.6 Å, β = 104.9°) and diffracted beyond 1.55 Å. A highly redundant X-ray diffraction data set from the C2 crystal form collected on a copper rotating-anode generator (λ = 1.542 Å) clearly defined the positions of the four Fe atoms present in the asymmetric unit by SAD methods. A MAD experiment at the iron absorption edge confirmed the positions of the previously determined iron sites and provided better phases for model building and refinement. Molecular replacement using the P21 data set was successful using a preliminary trace as a search model. A similar arrangement of the four protein molecules could be observed

  13. Assessing the abundance, seasonal questing activity, and Borrelia and tick-borne encephalitis virus (TBEV) prevalence of Ixodes ricinus ticks in a Lyme borreliosis endemic area in Southwest Finland.

    Science.gov (United States)

    Sormunen, Jani J; Klemola, Tero; Vesterinen, Eero J; Vuorinen, Ilppo; Hytönen, Jukka; Hänninen, Jari; Ruohomäki, Kai; Sääksjärvi, Ilari E; Tonteri, Elina; Penttinen, Ritva

    2016-02-01

    Studies have revealed that Ixodes ricinus (Acari: Ixodidae) have become more abundant and their geographical distribution extended northwards in some Nordic countries during the past few decades. However, ecological data of tick populations in Finland are sparse. In the current study, I. ricinus abundance, seasonal questing activity, and their Borrelia spp. and tick-borne encephalitis virus (TBEV) prevalence were evaluated in a Lyme borreliosis endemic area in Southwest Finland, Seili Island, where a previous study mapping tick densities was conducted 12 years earlier. A total of 1940 ticks were collected from five different biotopes by cloth dragging during May-September 2012. The overall tick density observed was 5.2 ticks/100m(2) for nymphs and adults. Seasonal questing activity of ticks differed between biotopes and life stages: bimodal occurrences were observed especially for nymphal and adult ticks in forested biotopes, while larvae in pastures exhibited mostly unimodal occurrence. Prevalence of Borrelia and TBEV in ticks was evaluated using conventional and real-time PCR. All samples were negative for TBEV. Borrelia prevalence was 25.0% for adults (n=44) and the minimum infection rate (MIR) 5.6% for pooled nymph samples (191 samples, 1-14 individuals per sample; 30/191 positive). No Borrelia were detected in pooled larval samples (63 samples, 1-139 individuals per sample). Five species of Borrelia were identified from the samples: B. afzelii, B. burgdorferi s.s., B. garinii, B. valaisiana and B. miyamotoi. In Finland, B. valaisiana and B. miyamotoi have previously been reported from the Åland Islands but not from the mainland or inner archipelago. The results of the present study suggest an increase in I. ricinus abundance on the island. PMID:26548608

  14. Molecular Typing of Borrelia burgdorferi Sensu Lato: Taxonomic, Epidemiological, and Clinical Implications

    OpenAIRE

    Wang, Guiqing; Dam, Alje P. van; Schwartz, Ira; Dankert, Jacob

    1999-01-01

    Borrelia burgdorferi sensu lato, the spirochete that causes human Lyme borreliosis (LB), is a genetically and phenotypically divergent species. In the past several years, various molecular approaches have been developed and used to determine the phenotypic and genetic heterogeneity within the LB-related spirochetes and their potential association with distinct clinical syndromes. These methods include serotyping, multilocus enzyme electrophoresis, DNA-DNA reassociation analysis, rRNA gene res...

  15. Group cubization

    OpenAIRE

    Osajda, Damian

    2016-01-01

    We present a procedure of group cubization: It results in a group whose some features resemble the ones of a given group, and which acts without fixed points on a CAT(0) cubical complex. As a main application we establish lack of Kazhdan's property (T) for Burnside groups. Other applications include new constructions of non-exact groups.

  16. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  17. The urokinase receptor (uPAR) facilitates clearance of Borrelia burgdorferi

    NARCIS (Netherlands)

    J.W.R. Hovius; M.F. Bijlsma; G.J.W. van der Windt; W.J. Wiersinga; B.J.D. Boukens; J. Coumou; A. Oei; R. de Beer; A.F. de Vos; C. van 't Veer; A.P. van Dam; P. Wang; E. Fikrig; M.M. Levi; J.J.T.H. Roelofs; T. van der Poll

    2009-01-01

    The causative agent of Lyme borreliosis, the spirochete Borrelia burgdorferi, has been shown to induce expression of the urokinase receptor (uPAR); however, the role of uPAR in the immune response against Borrelia has never been investigated. uPAR not only acts as a proteinase receptor, but can also

  18. Group Flow and Group Genius

    Science.gov (United States)

    Sawyer, Keith

    2015-01-01

    Keith Sawyer views the spontaneous collaboration of group creativity and improvisation actions as "group flow," which organizations can use to function at optimum levels. Sawyer establishes ideal conditions for group flow: group goals, close listening, complete concentration, being in control, blending egos, equal participation, knowing…

  19. Group morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2000-01-01

    In its original form, mathematical morphology is a theory of binary image transformations which are invariant under the group of Euclidean translations. This paper surveys and extends constructions of morphological operators which are invariant under a more general group TT, such as the motion group

  20. Abelian Groups

    Energy Technology Data Exchange (ETDEWEB)

    Mishina, A.P.

    1995-10-15

    This fifth survey of reviews on abelian groups comprises papers reviewed in 1985-1992. Just as in the preceding surveys, the issues concerning finite abelian groups, topological groups, ordered groups, group algebras, modules (with rare exceptions), and topics on logic are not considered. The issues on the lattice of subgroups of an abelian group are included in Section 11. In contrast to the fourth survey, this one does not contain Sections 6 (N-high subgroups), 9 (rings with a given additive group), and 10 (valuated groups); since only a few papers treated these topics, the material discussed earlier in Sections 9, and 10 is now included in Section 11 and the material of the former Section 6 will be found in Sections 1, 7, 8, and 11 of this survey. On the other hand, the fifth survey has three new sections devoted to separable groups (a new Sect. 5), Butler groups (a new Sect. 6), and the endormorphism rings and automorphism groups of abelian groups (a new Sect. 9).

  1. Permutation groups

    CERN Document Server

    Passman, Donald S

    2012-01-01

    This volume by a prominent authority on permutation groups consists of lecture notes that provide a self-contained account of distinct classification theorems. A ready source of frequently quoted but usually inaccessible theorems, it is ideally suited for professional group theorists as well as students with a solid background in modern algebra.The three-part treatment begins with an introductory chapter and advances to an economical development of the tools of basic group theory, including group extensions, transfer theorems, and group representations and characters. The final chapter feature

  2. Galaxy Groups

    Science.gov (United States)

    Tully, R. Brent

    2015-02-01

    Galaxy groups can be characterized by the radius of decoupling from cosmic expansion, the radius of the caustic of second turnaround, and the velocity dispersion of galaxies within this latter radius. These parameters can be a challenge to measure, especially for small groups with few members. In this study, results are gathered pertaining to particularly well-studied groups over four decades in group mass. Scaling relations anticipated from theory are demonstrated and coefficients of the relationships are specified. There is an update of the relationship between light and mass for groups, confirming that groups with mass of a few times {{10}12}{{M}⊙ } are the most lit up while groups with more and less mass are darker. It is demonstrated that there is an interesting one-to-one correlation between the number of dwarf satellites in a group and the group mass. There is the suggestion that small variations in the slope of the luminosity function in groups are caused by the degree of depletion of intermediate luminosity systems rather than variations in the number per unit mass of dwarfs. Finally, returning to the characteristic radii of groups, the ratio of first to second turnaround depends on the dark matter and dark energy content of the universe and a crude estimate can be made from the current observations of {{Ω}matter}˜ 0.15 in a flat topology, with a 68% probability of being less than 0.44.

  3. Galaxy groups

    Energy Technology Data Exchange (ETDEWEB)

    Brent Tully, R. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2015-02-01

    Galaxy groups can be characterized by the radius of decoupling from cosmic expansion, the radius of the caustic of second turnaround, and the velocity dispersion of galaxies within this latter radius. These parameters can be a challenge to measure, especially for small groups with few members. In this study, results are gathered pertaining to particularly well-studied groups over four decades in group mass. Scaling relations anticipated from theory are demonstrated and coefficients of the relationships are specified. There is an update of the relationship between light and mass for groups, confirming that groups with mass of a few times 10{sup 12}M{sub ⊙} are the most lit up while groups with more and less mass are darker. It is demonstrated that there is an interesting one-to-one correlation between the number of dwarf satellites in a group and the group mass. There is the suggestion that small variations in the slope of the luminosity function in groups are caused by the degree of depletion of intermediate luminosity systems rather than variations in the number per unit mass of dwarfs. Finally, returning to the characteristic radii of groups, the ratio of first to second turnaround depends on the dark matter and dark energy content of the universe and a crude estimate can be made from the current observations of Ω{sub matter}∼0.15 in a flat topology, with a 68% probability of being less than 0.44.

  4. Galaxy Groups

    CERN Document Server

    Tully, R Brent

    2014-01-01

    Galaxy groups can be characterized by the radius of decoupling from cosmic expansion, the radius of the caustic of second turnaround, and the velocity dispersion of galaxies within this latter radius. These parameters can be a challenge to measure, especially for small groups with few members. In this study, results are gathered pertaining to particularly well studied groups over four decades in group mass. Scaling relations anticipated from theory are demonstrated and coefficients of the relationships are specified. There is an update of the relationship between light and mass for groups, confirming that groups with mass of a few times 10^12 Msun are the most lit up while groups with more and less mass are darker. It is demonstrated that there is an interesting one-to-one correlation between the number of dwarf satellites in a group and the group mass. There is the suggestion that small variations in the slope of the luminosity function in groups are caused by the degree of depletion of intermediate luminosi...

  5. Hydra groups

    CERN Document Server

    Dison, Will

    2010-01-01

    We give examples of CAT(0), biautomatic, free-by-cyclic, one-relator groups which have finite-rank free subgroups of huge (Ackermannian) distortion. This leads to elementary examples of groups whose Dehn functions are similarly extravagant. This behaviour originates in manifestations of Hercules-versus-the-hydra battles in string-rewriting.

  6. Reflection groups

    International Nuclear Information System (INIS)

    In 2005, PISA organised proactive meetings of reflection groups on involvement in decision making, expert culture and ethical aspects of radiation protection.All reflection group meetings address particular targeted audiences while the output publication in book form is put forward

  7. Algebraic Groups

    DEFF Research Database (Denmark)

    2007-01-01

    The workshop continued a series of Oberwolfach meetings on algebraic groups, started in 1971 by Tonny Springer and Jacques Tits who both attended the present conference. This time, the organizers were Michel Brion, Jens Carsten Jantzen, and Raphaël Rouquier. During the last years, the subject of...... algebraic groups (in a broad sense) has seen important developments in several directions, also related to representation theory and algebraic geometry. The workshop aimed at presenting some of these developments in order to make them accessible to a "general audience" of algebraic group-theorists, and to...

  8. Group Grammar

    Science.gov (United States)

    Adams, Karen

    2015-01-01

    In this article Karen Adams demonstrates how to incorporate group grammar techniques into a classroom activity. In the activity, students practice using the target grammar to do something they naturally enjoy: learning about each other.

  9. Abelian groups

    CERN Document Server

    Fuchs, László

    2015-01-01

    Written by one of the subject’s foremost experts, this book focuses on the central developments and modern methods of the advanced theory of abelian groups, while remaining accessible, as an introduction and reference, to the non-specialist. It provides a coherent source for results scattered throughout the research literature with lots of new proofs. The presentation highlights major trends that have radically changed the modern character of the subject, in particular, the use of homological methods in the structure theory of various classes of abelian groups, and the use of advanced set-theoretical methods in the study of undecidability problems. The treatment of the latter trend includes Shelah’s seminal work on the undecidability in ZFC of Whitehead’s Problem; while the treatment of the former trend includes an extensive (but non-exhaustive) study of p-groups, torsion-free groups, mixed groups, and important classes of groups arising from ring theory. To prepare the reader to tackle these topics, th...

  10. Group dynamics.

    Science.gov (United States)

    Scandiffio, A L

    1990-12-01

    Group dynamics play a significant role within any organization, culture, or unit. The important thing to remember with any of these structures is that they are made up of people--people with different ideas, motivations, background, and sometimes different agendas. Most groups, formal or informal, look for a leader in an effort to maintain cohesiveness of the unit. At times, that cultural bond must be developed; once developed, it must be nurtured. There are also times that one of the group no longer finds the culture comfortable and begins to act out behaviorally. It is these times that become trying for the leader as she or he attempts to remain objective when that which was once in the building phase of group cohesiveness starts to fall apart. At all times, the manager must continue to view the employee creating the disturbance as an integral part of the group. It is at this time that it is beneficial to perceive the employee exhibiting problem behaviors as a special employee, as one who needs the benefit of your experience and skills, as one who is still part of the group. It is also during this time that the manager should focus upon her or his own views in the area of power, communication, and the corporate culture of the unit that one has established before attempting to understand another's point of view. Once we understand our own motivation and accept ourselves, it is then that we may move on to offer assistance to another. Once we understand our insecurities recognizing staff dysfunction as a symptom of system dysfunction will not be so threatening to the concept of the manager that we perceive ourselves to be. It takes a secure person to admit that she or he favors staff before deciding to do something to change things. The important thing to know is that it can be done. The favored staff can find a new way of relating to others, the special employee can find new modes of behavior (and even find self-esteem in the process), the group can find new ways

  11. Group representations

    CERN Document Server

    Karpilovsky, G

    1994-01-01

    This third volume can be roughly divided into two parts. The first part is devoted to the investigation of various properties of projective characters. Special attention is drawn to spin representations and their character tables and to various correspondences for projective characters. Among other topics, projective Schur index and projective representations of abelian groups are covered. The last topic is investigated by introducing a symplectic geometry on finite abelian groups. The second part is devoted to Clifford theory for graded algebras and its application to the corresponding theory

  12. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  13. New insights into Lyme disease

    Directory of Open Access Journals (Sweden)

    Brandon N. Peacock

    2015-08-01

    Full Text Available Lyme borreliosis is transmitted through the bite of a tick that is infected by the bacterial spirochete Borrelia burgdorferi. Clinical manifestation of the disease can lead to heart conditions, neurological disorders, and inflammatory disorders. Oxidative stress has been implicated in the pathogenesis of many human diseases. The aim of this study was to investigate the mechanisms of oxidative stress and intracellular communication in Lyme borreliosis patients. Mitochondrial superoxide and cytosolic ionized calcium was measured in peripheral blood mononuclear cells (PBMCs of Lyme borreliosis patients and healthy controls. Mitochondrial superoxide levels were significantly higher (p<0.0001 in Lyme borreliosis patients (n=32 as compared to healthy controls (n=30. Significantly low (p<0.0001 levels of cytosolic ionized calcium were also observed in Lyme borreliosis patients (n=11 when compared to healthy controls (n=11. These results indicate that there is an imbalance of reactive oxygen species and cytosolic calcium in Lyme borreliosis patients. The results further suggest that oxidative stress and interrupted intracellular communication may ultimately contribute to a condition of mitochondrial dysfunction in the immune cells of Lyme borreliosis patients.

  14. Tectaria group

    NARCIS (Netherlands)

    Holttum, R.E.

    1991-01-01

    Polypodiaceae subfam. Dryopteridoideae section A, auct.: C. Chr. in Verdoorn, Man. Pteridol. (1938) 543, p.p. Aspidiaceae tribe Aspidieae auct.: Ching, Sunyatsenia 5 (1940) 250, excl. Lomariopsis and related genera. — Aspidiaceae, group of Ctenitis Copel., Gen. Fil. (1947) 153. Aspidiaceae auct.: Pi

  15. Group Learning.

    Science.gov (United States)

    Black, Susan

    1992-01-01

    Research suggests that cooperative learning works best when students are first taught group-processing skills, such as leadership, decision making, communication, trust building, and conflict management. Inadequate teacher training and boring assignments can torpedo cooperative learning efforts. Administrators should reassure teachers with…

  16. Group play

    DEFF Research Database (Denmark)

    Tychsen, Anders; Hitchens, Michael; Brolund, Thea;

    2008-01-01

    Role-playing games (RPGs) are a well-known game form, existing in a number of formats, including tabletop, live action, and various digital forms. Despite their popularity, empirical studies of these games are relatively rare. In particular there have been few examinations of the effects of the...... various formats used by RPGs on the gaming experience. This article presents the results of an empirical study, examining how multi-player tabletop RPGs are affected as they are ported to the digital medium. Issues examined include the use of disposition assessments to predict play experience, the effect...... of group dynamics, the influence of the fictional game characters and the comparative play experience between the two formats. The results indicate that group dynamics and the relationship between the players and their digital characters, are integral to the quality of the gaming experience in...

  17. Group therapy

    International Nuclear Information System (INIS)

    Full text: In his review 'Genesis of Unified Gauge Theories' at the symposium in Honour of Abdus Salam (June, page 23), Tom Kibble of Imperial College, London, looked back to the physics events around Salam from 1959-67. He described how, in the early 1960s, people were pushing to enlarge the symmetry of strong interactions beyond the SU(2) of isospin and incorporate the additional strangeness quantum number. Kibble wrote - 'Salam had students working on every conceivable symmetry group. One of these was Yuval Ne'eman, who had the good fortune and/or prescience to work on SU(3). From that work, and of course from the independent work of Murray Gell- Mann, stemmed the Eightfold Way, with its triumphant vindication in the discovery of the omega-minus in 1964.' Yuval Ne'eman writes - 'I was the Defence Attaché at the Israeli Embassy in London and was admitted by Salam as a part-time graduate student when I arrived in 1958. I started research after resigning from the Embassy in May 1960. Salam suggested a problem: provide vector mesons with mass - the problem which was eventually solved by Higgs, Guralnik, Kibble,.... (as described by Kibble in his article). I explained to Salam that I had become interested in symmetry. Nobody at Imperial College at the time, other than Salam himself, was doing anything in groups, and attention further afield was focused on the rotation - SO(N) - groups. Reacting to my own half-baked schemes, Salam told me to forget about the rotation groups he taught us, and study group theory in depth, directing me to Eugene Dynkin's classification of Lie subalgebras, about which he had heard from Morton Hamermesh. I found Dynkin incomprehensible without first learning about Lie algebras from Henri Cartan's thesis, which luckily had been reproduced by Dynkin in his 1946 thesis, using his diagram method. From a copy of a translation of Dynkin's thesis which I found in the British Museum Library, I

  18. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group, established at the start of 2010, has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure There are now 55 CMS Centres worldwide that are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS offline and computing operations, hosting dedicated analysis efforts such as during the CMS Heavy Ion lead-lead running. With a majority of CMS sub-detectors now operating in a “shifterless” mode, many monitoring operations are now routinely performed from there, rather than in the main Control Room at P5. The CMS Communications Group, CERN IT and the EVO team are providing excellent videoconferencing support for the rapidly-increasing number of CMS meetings. In parallel, CERN IT and ...

  19. Mutations in the Borrelia burgdorferi Flagellar Type III Secretion System Genes fliH and fliI Profoundly Affect Spirochete Flagellar Assembly, Morphology, Motility, Structure, and Cell Division

    Science.gov (United States)

    Gao, Lihui; Zhao, Xiaowei; Liu, Jun; Norris, Steven J.

    2015-01-01

    ABSTRACT The Lyme disease spirochete Borrelia burgdorferi migrates to distant sites in the tick vectors and mammalian hosts through robust motility and chemotaxis activities. FliH and FliI are two cytoplasmic proteins that play important roles in the type III secretion system (T3SS)-mediated export and assembly of flagellar structural proteins. However, detailed analyses of the roles of FliH and FliI in B. burgdorferi have not been reported. In this study, fliH and fliI transposon mutants were utilized to dissect the mechanism of the Borrelia type III secretion system. The fliH and fliI mutants exhibited rod-shaped or string-like morphology, greatly reduced motility, division defects (resulting in elongated organisms with incomplete division points), and noninfectivity in mice by needle inoculation. Mutants in fliH and fliI were incapable of translational motion in 1% methylcellulose or soft agar. Inactivation of either fliH or fliI resulted in the loss of the FliH-FliI complex from otherwise intact flagellar motors, as determined by cryo-electron tomography (cryo-ET). Flagellar assemblies were still present in the mutant cells, albeit in lower numbers than in wild-type cells and with truncated flagella. Genetic complementation of fliH and fliI mutants in trans restored their wild-type morphology, motility, and flagellar motor structure; however, full-length flagella and infectivity were not recovered in these complemented mutants. Based on these results, disruption of either fliH or fliI in B. burgdorferi results in a severe defect in flagellar structure and function and cell division but does not completely block the export and assembly of flagellar hook and filament proteins. PMID:25968649

  20. Lego Group

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Pedersen, Torben; Slepniov, Dmitrij

    2010-01-01

    The last years’ rather adventurous journey from 2004 to 2009 had taught the fifth-largest toy-maker in the world - the LEGO Group - the importance of managing the global supply chain effectively. In order to survive the largest internal financial crisis in its roughly 70 years of existence, the...... phase out the entire sourcing collaboration with Flextronics. This sudden change in its sourcing strategy posed LEGO management with a number of caveats. Despite the bright forecasts, the collaboration did not fulfill the initial expectations, and the company needed to understand why this had happened...

  1. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS Offline and Computing operations, and a number of subdetector shifts can now take place there, rather than in the main Control Room at P5. A new CMS meeting room has been equipped for videoconferencing in building 42, next to building 40. Our building 28 meeting room and the facilities at P5 will be refurbished soon and plans are underway to steadily upgrade the ageing equipment in all 15 CMS meeting rooms at CERN. The CMS evaluation of the Vidyo tool indicates that it is not yet ready to be considered as a potential replacement for EVO. The Communications Group provides the CMS-TV (web) cha...

  2. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The CMS Communications Group, established at the start of 2010, has been strengthening the activities in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The Communications Group has invested a lot of effort to support the operations needs of CMS. Hence, the CMS Centres where physicists work on remote CMS shifts, Data Quality Monitoring, and Data Analysis are running very smoothly. There are now 55 CMS Centres worldwide, up from just 16 at the start of CMS data-taking. The latest to join are Imperial College London, the University of Iowa, and the Università di Napoli. The CMS Centre@CERN in Meyrin, which is now full repaired after the major flooding at the beginning of the year, has been at the centre of CMS offline and computing operations, most recently hosting a large fraction of the CMS Heavy Ion community during the lead-lead run. A number of sub-detector shifts can now take pla...

  3. Cardiovascular group

    Science.gov (United States)

    Blomqvist, Gunnar

    1989-01-01

    As a starting point, the group defined a primary goal of maintaining in flight a level of systemic oxygen transport capacity comparable to each individual's preflight upright baseline. The goal of maintaining capacity at preflight levels would seem to be a reasonable objective for several different reasons, including the maintenance of good health in general and the preservation of sufficient cardiovascular reserve capacity to meet operational demands. It is also important not to introduce confounding variables in whatever other physiological studies are being performed. A change in the level of fitness is likely to be a significant confounding variable in the study of many organ systems. The principal component of the in-flight cardiovascular exercise program should be large-muscle activity such as treadmill exercise. It is desirable that at least one session per week be monitored to assure maintenance of proper functional levels and to provide guidance for any adjustments of the exercise prescription. Appropriate measurements include evaluation of the heart-rate/workload or the heart-rate/oxygen-uptake relationship. Respiratory gas analysis is helpful by providing better opportunities to document relative workload levels from analysis of the interrelationships among VO2, VCO2, and ventilation. The committee felt that there is no clear evidence that any particular in-flight exercise regimen is protective against orthostatic hypotension during the early readaptation phase. Some group members suggested that maintenance of the lower body muscle mass and muscle tone may be helpful. There is also evidence that late in-flight interventions to reexpand blood volume to preflight levels are helpful in preventing or minimizing postflight orthostatic hypotension.

  4. Group evaporation

    Science.gov (United States)

    Shen, Hayley H.

    1991-01-01

    Liquid fuel combustion process is greatly affected by the rate of droplet evaporation. The heat and mass exchanges between gas and liquid couple the dynamics of both phases in all aspects: mass, momentum, and energy. Correct prediction of the evaporation rate is therefore a key issue in engineering design of liquid combustion devices. Current analytical tools for characterizing the behavior of these devices are based on results from a single isolated droplet. Numerous experimental studies have challenged the applicability of these results in a dense spray. To account for the droplets' interaction in a dense spray, a number of theories have been developed in the past decade. Herein, two tasks are examined. One was to study how to implement the existing theoretical results, and the other was to explore the possibility of experimental verifications. The current theoretical results of group evaporation are given for a monodispersed cluster subject to adiabatic conditions. The time evolution of the fluid mechanic and thermodynamic behavior in this cluster is derived. The results given are not in the form of a subscale model for CFD codes.

  5. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The recently established CMS Communications Group, led by Lucas Taylor, has been busy in all three of its main are areas of responsibility: Communications Infrastructure, Information Systems, and Outreach and Education Communications Infrastructure The damage caused by the flooding of the CMS Centre@CERN on 21st December has been completely repaired and all systems are back in operation. Major repairs were made to the roofs, ceilings and one third of the floor had to be completely replaced. Throughout these works, the CMS Centre was kept operating and even hosted a major press event for first 7 TeV collisions, as described below. Incremental work behind the scenes is steadily improving the quality of the CMS communications infrastructure, particularly Webcasting, video conferencing, and meeting rooms at CERN. CERN/IT is also deploying a pilot service of a new videoconference tool called Vidyo, to assess whether it might provide an enhanced service at a lower cost, compared to the EVO tool currently in w...

  6. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin is particularly busy at the moment, hosting about 50 physicists taking part in the heavy-ion data-taking and analysis. Three new CMS meeting room will be equipped for videoconferencing in early 2012: 40/5B-08, 42/R-031, and 28/S-029. The CMS-TV service showing LHC Page 1, CMS Page 1, etc. (http://cmsdoc.cern.ch/cmscc/projector/index.jsp) is now also available for mobile devices: http://cern.ch/mcmstv. Figure 12: Screenshots of CMS-TV for mobile devices Information Systems CMS has a new web site: (http://cern.ch/cms) using a modern web Content Management System to ensure content and links are managed and updated easily and coherently. It covers all CMS sub-projects and groups, replacing the iCMS internal pages. It also incorporates the existing CMS public web site (http:/...

  7. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2012-01-01

      Outreach and Education We are fortunate that our research has captured the public imagination, even though this inevitably puts us under the global media spotlight, as we saw with the Higgs seminar at CERN in December, which had 110,000 distinct webcast viewers. The media interest was huge with 71 media organisations registering to come to CERN to cover the Higgs seminar, which was followed by a press briefing with the DG and Spokespersons. This event resulted in about 2,000 generally positive stories in the global media. For this seminar, the CMS Communications Group prepared up-to-date news and public material, including links to the CMS results, animations and event displays [http://cern.ch/go/Ch8thttp://cern.ch/go/Ch8t]. There were 44,000 page-views on the CMS public website, with the Higgs news article being by far the most popular item. CMS event displays from iSpy are fast becoming the iconic media images, featuring on numerous major news outlets (BBC, CNN, MSN...) as well as in the sci...

  8. From mapping class groups to automorphism groups of free groups

    DEFF Research Database (Denmark)

    Wahl, Nathalie

    2005-01-01

    We show that the natural map from the mapping class groups of surfaces to the automorphism groups of free groups, induces an infinite loop map on the classifying spaces of the stable groups after plus construction. The proof uses automorphisms of free groups with boundaries which play the role of...... mapping class groups of surfaces with several boundary components....

  9. Antimicrobial activity of two bactenecins against spirochetes.

    OpenAIRE

    Scocchi, M; Romeo, D; Cinco, M

    1993-01-01

    Bac5 and Bac7 are antimicrobial peptides of bovine neutrophils that act on enteric gram-negative bacteria. We report here that these two peptides immobilize and kill Leptospira interrogans and Leptospira biflexa with MBCs of 6 to 25 micrograms/ml. Conversely, although both peptides bind to Borrelia burgdorferi, the organism is resistant to their action.

  10. Integrated Groups and Smooth Distribution Groups

    Institute of Scientific and Technical Information of China (English)

    Pedro J. MIANA

    2007-01-01

    In this paper, we prove directly that α-times integrated groups define algebra homo-morphisms. We also give a theorem of equivalence between smooth distribution groups and α-times integrated groups.

  11. Which finite simple groups are unit groups?

    DEFF Research Database (Denmark)

    Davis, Christopher James; Occhipinti, Tommy

    2014-01-01

    We prove that if G is a finite simple group which is the unit group of a ring, then G is isomorphic to either (a) a cyclic group of order 2; (b) a cyclic group of prime order 2^k −1 for some k; or (c) a projective special linear group PSLn(F2) for some n ≥ 3. Moreover, these groups do all occur as...... unit groups. We deduce this classification from a more general result, which holds for groups G with no non-trivial normal 2-subgroup....

  12. Polymerase chain reaction in diagnosis of Borrelia burgdorferi infections and studies on taxonomic classification

    DEFF Research Database (Denmark)

    Lebech, Anne-Mette

    2002-01-01

    Lyme borreliosis caused by the spirochete Borrelia burgdorferi is now the most common vectorborne disease in North America, Europe and Asia. It is a multisystemic infection which may cause skin, neurological, cardiac or rheumatologic disorders. The aims of the present thesis were: (i) to develop a...... PCR assay for direct detection of B. burgdorferi DNA and to evaluate the diagnostic utility of PCR in clinical specimens from patients with Lyme borreliosis and (ii) to study the taxonomic classification of B. burgdorferi isolates and its implications for epidemiology and clinical presentation....... Laboratory diagnosis of Lyme borreliosis by direct demonstration of B. burgdorferi in clinical specimens would compared to current serology allow (i) optimal specificity, (ii) increased sensitivity during the first weeks of infection, when the antibody response is not yet detectable and (iii) discrimination...

  13. Group Work Publication-1991.

    Science.gov (United States)

    Zimpfer, David G.

    1992-01-01

    Lists 21 new publications in group work, of which 9 are reviewed. Those discussed include publications on group counseling and psychotherapy, structured groups, support groups, psychodrama, and social group work. (Author/NB)

  14. Inhibition of the Production of Anti-OspA Borreliacidal Antibody with T Cells from Hamsters Vaccinated against Borrelia burgdorferi

    OpenAIRE

    Jensen, Jani R.; Du Chateau, Brian K.; Munson, Erik L.; Callister, Steven M.; Schell, Ronald F.

    1998-01-01

    The serious morbidity associated with Lyme borreliosis has focused considerable effort on the development of a comprehensive vaccine for protection against infection with Borrelia burgdorferi. Induction of borreliacidal antibody by vaccination or infection has been shown to correlate with protection of humans and animals against infection with the Lyme spirochete. In this report, we showed that high levels of borreliacidal antibody (titer of 1,280) were produced in vitro when T and B cells fr...

  15. An Enhanced ELISPOT Assay for Sensitive Detection of Antigen-Specific T Cell Responses to Borrelia burgdorferi

    OpenAIRE

    Kellermann, Gottfried H.; Lehmann, Paul V; Diana R. Roen; Chenggang Jin

    2013-01-01

    Lyme Borreliosis is an infectious disease caused by the spirochete Borrelia burgdorferi that is transmitted through the bite of infected ticks. Both B cell-mediated humoral immunity and T cell immunity develop during natural Borrelia infection. However, compared with humoral immunity, the T cell response to Borrelia infection has not been well elucidated. In this study, a novel T cell-based assay was developed and validated for the sensitive detection of antigen-specific T cell response to B....

  16. Anaphylactoid reaction caused by sodium ceftriaxone in two horses experimentally infected by Borrelia burgdorferi

    OpenAIRE

    Basile, Roberta Carvalho; Rivera, Gabriela Gomes; Del Rio, Lara Antoniassi; de Bonis, Talissa Camargo Mantovani; do Amaral, Gabriel Paiva Domingues; Giangrecco, Edson; Ferraz, Guilherme; Yoshinari, Natalino Hajime; Canola, Paulo Aléscio; Queiroz Neto, Antonio

    2015-01-01

    Background Lyme borreliosis is a disease transmitted by ticks to mammals, especially in horses and humans. Caused by a spirochete Borrelia burgdorferi, it can result in lameness, arthritis, carditis, dermatitis and neurological signs. Anaphylactoid reactions are severe responses caused by direct action of substances (drugs, toxins), which can pose risks to life. Still poorly documented in horses, these reactions are caused by the effects of inflammatory mediators such as histamine, kinins and...

  17. A New Borrelia Species Defined by Multilocus Sequence Analysis of Housekeeping Genes▿ †

    OpenAIRE

    Margos, Gabriele; Vollmer, Stephanie A.; Cornet, Muriel; Garnier, Martine; Fingerle, Volker; Wilske, Bettina; Bormane, Antra; Vitorino, Liliana; Collares-Pereira, Margarida; Drancourt, Michel; Kurtenbach, Klaus

    2009-01-01

    Analysis of Lyme borreliosis (LB) spirochetes, using a novel multilocus sequence analysis scheme, revealed that OspA serotype 4 strains (a rodent-associated ecotype) of Borrelia garinii were sufficiently genetically distinct from bird-associated B. garinii strains to deserve species status. We suggest that OspA serotype 4 strains be raised to species status and named Borrelia bavariensis sp. nov. The rooted phylogenetic trees provide novel insights into the evolutionary history of LB spiroche...

  18. Induktion von Matrixmetalloproteinasen und Interleukin-18 durch Borrelia burgdorferi in vivo und in vitro

    OpenAIRE

    Unsicker, Catrin

    2010-01-01

    Lyme borreliosis is a systemic disease involving the skin, the musculoskeletal system, the heart and the central nervous system. The shift of the cytokine pattern towards the Th1 response is one characteristic feature of the disease. Recently, interleukin-18 has been described to induce interferon-gamma. Therefore the potential role of IL-18 in Lyme disease has been studied. In addition, it is not clear how the spirochetes can disseminate within the host organism...

  19. Lymská borelióza u psa

    OpenAIRE

    Horáčková, Pavlína

    2014-01-01

    Lyme borreliosis (Lyme disease) is a tick-borne disease caused by spirochetes of the genus Borrelia. It affects canines, humans and other warm-blooded animals. It manifests itself mainly by physical disabilities and that of nervous system, skin and heart. Its occurence in the Czech Republic is relatively frequent as well as the incidence of the main carriers of ticks (Ixodes Ricinus). Among the major reservoirs of the disease agent are rodents, deer, pets. The greatest risk of infection oc...

  20. Updates on Borrelia burgdorferi sensu lato complex with respect to public health

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor; Oliver, J. H., Jr.

    2011-01-01

    Roč. 2, č. 3 (2011), s. 123-128. ISSN 1877-959X R&D Projects: GA MŠk(CZ) LC06009; GA ČR GA206/09/1782 Institutional research plan: CEZ:AV0Z60220518 Keywords : Spirochetes * Borrelia * Genetic diversity * Lyme borreliosis * Distribution * New species Subject RIV: EE - Microbiology, Virology Impact factor: 2.370, year: 2011

  1. Group Composition, Group Interaction and Achievement in Cooperative Small Groups.

    Science.gov (United States)

    Webb, Noreen M.

    This study investigated interaction and achievement in cooperative small groups in four junior high school mathematics classrooms. Ninety-six students learned a one-week unit on consumer mathematics in mixed-ability or uniform-ability groups. Students in mixed-ability groups scored higher on a problem-solving test than students in uniform-ability…

  2. Group dynamic processes in email groups

    OpenAIRE

    Alpay, Esat

    2005-01-01

    Abstract Discussion is given on the relevance of group dynamic processes in promoting decision-making in email discussion groups. General theories on social facilitation and social loafing are considered in the context of email groups, as well as the applicability of psychodynamic and interaction-based models. It is argued that such theories may indeed provide insight into email group interactions, but that...

  3. Group Cohesion in Experiential Growth Groups

    Science.gov (United States)

    Steen, Sam; Vasserman-Stokes, Elaina; Vannatta, Rachel

    2014-01-01

    This article explores the effect of web-based journaling on changes in group cohesion within experiential growth groups. Master's students were divided into 2 groups. Both used a web-based platform to journal after each session; however, only 1 of the groups was able to read each other's journals. Quantitative data collected before and…

  4. Probability groups as orbits of groups

    International Nuclear Information System (INIS)

    The set of double cosets of a group with respect to a subgroup and the set of orbits of a group with respect to a group of automorphisms have structures which can be studied as multigroups, hypergroups or Pasch geometries. When the subgroup or the group of automorphisms are finite, the multivalued products can be provided with some weightages forming so-called Probability Groups. It is shown in this paper that some abstract probability groups can be realized as orbit spaces of groups. (author)

  5. Group theories: relevance to group safety studies.

    Science.gov (United States)

    Benevento, A L

    1998-01-01

    Promoting safety in the workplace has been attempted in a variety of ways. Increasingly, industries are using groups such as safety teams and quality circles to promote worker safety. Group influences on individual behavior and attitudes have long been studied in the social psychology literature, but the theories have not been commonly found outside the psychology arena. This paper describes the group theories of group polarization, risky shift, social loafing, groupthink and team think and attempts to apply these theories to existing studies that examine work group influences on safety. Interesting parallels were found but only one study examined group influences as their primary focus of research. Since groups are increasingly used for safety promotion, future research on safety that studies group influences with respect to current group theories is recommended. PMID:24441299

  6. AREVA group overview; Presentation du groupe AREVA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-08

    This document presents the Group Areva, a world nuclear industry leader, from a financial holding company to an industrial group, operating in two businesses: the nuclear energy and the components. The structure and the market of the group are discussed, as the financial assets. (A.L.B.)

  7. Group Dynamic Processes in Email Groups

    Science.gov (United States)

    Alpay, Esat

    2005-01-01

    Discussion is given on the relevance of group dynamic processes in promoting decision-making in email discussion groups. General theories on social facilitation and social loafing are considered in the context of email groups, as well as the applicability of psychodynamic and interaction-based models. It is argued that such theories may indeed…

  8. Interagency mechanical operations group numerical systems group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This report consists of the minutes of the May 20-21, 1971 meeting of the Interagency Mechanical Operations Group (IMOG) Numerical Systems Group. This group looks at issues related to numerical control in the machining industry. Items discussed related to the use of CAD and CAM, EIA standards, data links, and numerical control.

  9. Introduction to Sporadic Groups

    CERN Document Server

    Boya, Luis J

    2011-01-01

    This is an introduction to finite simple groups, in particular sporadic groups, intended for physicists. After a short review of group theory, we enumerate the $1+1+16=18$ families of finite simple groups, as an introduction to the sporadic groups. These are described next, in three levels of increasing complexity, plus the six isolated "pariah" groups. The (old) five Mathieu groups make up the first, smallest order level. The seven groups related to the Leech lattice, including the three Conway groups, constitute the second level. The third and highest level contains the Monster group $\\mathbb M$, plus seven other related groups. Next a brief mention is made of the remaining six pariah groups, thus completing the $5+7+8+6=26$ sporadic groups. The review ends up with a brief discussion of a few of physical applications of finite groups in physics, including a couple of recent examples which use sporadic groups.

  10. Introduction to Sporadic Groups

    Directory of Open Access Journals (Sweden)

    Luis J. Boya

    2011-01-01

    Full Text Available This is an introduction to finite simple groups, in particular sporadic groups, intended for physicists. After a short review of group theory, we enumerate the 1+1+16=18 families of finite simple groups, as an introduction to the sporadic groups. These are described next, in three levels of increasing complexity, plus the six isolated ''pariah'' groups. The (old five Mathieu groups make up the first, smallest order level. The seven groups related to the Leech lattice, including the three Conway groups, constitute the second level. The third and highest level contains the Monster group M, plus seven other related groups. Next a brief mention is made of the remaining six pariah groups, thus completing the 5+7+8+6=26 sporadic groups. The review ends up with a brief discussion of a few of physical applications of finite groups in physics, including a couple of recent examples which use sporadic groups.

  11. Experience with Group Supervision

    OpenAIRE

    Chen, Weiqin

    2006-01-01

    Supervision can take a few different forms. For example, it can be one-to-one supervision and it can also be group supervision. Group supervision is an important process within the scientific community. Many research groups use this form to supervise doctoral- and master students in groups. Some efforts have been made to study this process. For example, Samara (2002) studied the group supervision process in group writing. However, group supervision has not been studied thorough...

  12. Small Group Research

    Science.gov (United States)

    McGrath, Joseph E.

    1978-01-01

    Summarizes research on small group processes by giving a comprehensive account of the types of variables primarily studied in the laboratory. These include group structure, group composition, group size, and group relations. Considers effects of power, leadership, conformity to social norms, and role relationships. (Author/AV)

  13. Group B Strep Infection

    Science.gov (United States)

    MENU Return to Web version Group B Strep Infection Overview What is group B strep? Group B streptococcus, or group B strep for short, is a certain kind ... in the intestine, rectum, and vagina (in women). Group B strep doesn’t usually cause problems in ...

  14. Redefining Cohesiveness in Groups.

    Science.gov (United States)

    Keyton, Joann; Springston, Jeff

    1990-01-01

    Attempted to replicate and extend research on work of Kelly and Duran in assessing relationship of group member perceptions of group interaction to group effectiveness. Concludes perceived similarity may not always align with perceptions of cohesiveness. (Author/ABL)

  15. Higher arithmetic Chow groups

    OpenAIRE

    Burgos Gil, José Ignacio; Feliu, E.

    2009-01-01

    We give a new construction of higher arithmetic Chow groups for quasi-projective arithmetic varieties over a field. Our definition agrees with the higher arithmetic Chow groups defined by Goncharov for projective arithmetic varieties over a field. These groups are the analogue, in the Arakelov context, of the higher algebraic Chow groups defined by Bloch. The degree zero group agrees with the arithmetic Chow groups of Burgos. Our new construction is shown to be a contravariant functor and is ...

  16. Higher arithmetic Chow groups

    DEFF Research Database (Denmark)

    Gil, J. I. Burgos; Feliu, Elisenda

    2012-01-01

    context, of the higher algebraic Chow groups defined by Bloch. For projective varieties the degree zero group agrees with the arithmetic Chow groups defined by Gillet and Soulé, and in general with the arithmetic Chow groups of Burgos. Our new construction is shown to be a contravariant functor and is...... endowed with a product structure, which is commutative and associative....

  17. Assertive Training in Groups

    Science.gov (United States)

    Sansbury, David L.

    1974-01-01

    This article describes a group approach to helping the nonassertive client. After describing the group composition and goals, he presents a session by session description for conducting the assertive training group. In addition, he presents suggestions based on experiences in leading the group. (Author)

  18. Robust Group Linkage

    OpenAIRE

    Li, Pei; Dong, Xin Luna; Guo, Songtao; Maurino, Andrea; Srivastava, Divesh

    2015-01-01

    We study the problem of group linkage: linking records that refer to entities in the same group. Applications for group linkage include finding businesses in the same chain, finding conference attendees from the same affiliation, finding players from the same team, etc. Group linkage faces challenges not present for traditional record linkage. First, although different members in the same group can share some similar global values of an attribute, they represent different entities so can also...

  19. Pretty Private Group Management

    CERN Document Server

    Heen, Olivier; Neumann, Christoph; Onno, Stéphane

    2011-01-01

    Group management is a fundamental building block of today's Internet applications. Mailing lists, chat systems, collaborative document edition but also online social networks such as Facebook and Twitter use group management systems. In many cases, group security is required in the sense that access to data is restricted to group members only. Some applications also require privacy by keeping group members anonymous and unlinkable. Group management systems routinely rely on a central authority that manages and controls the infrastructure and data of the system. Personal user data related to groups then becomes de facto accessible to the central authority. In this paper, we propose a completely distributed approach for group management based on distributed hash tables. As there is no enrollment to a central authority, the created groups can be leveraged by various applications. Following this paradigm we describe a protocol for such a system. We consider security and privacy issues inherently introduced by rem...

  20. Groups as Graphs

    CERN Document Server

    Kandasamy, W B Vasantha

    2009-01-01

    For the first time we represent every finite group in the form of a graph in this book. The authors choose to call these graphs as identity graph, since the main role in obtaining the graph is played by the identity element of the group. This study is innovative because through this description one can immediately look at the graph and say the number of elements in the group G which are self-inversed. Also study of different properties, like the subgroups of a group, normal subgroups of a group, p-sylow subgroups of a group and conjugate elements of a group are carried out using the identity graph of the group in this book. This book has four chapters. The first chapter is introductory. The second chapter represents groups as graphs. In the third chapter, we have defined similar types of graphs for algebraic structures like commutative semigroups, loops, commutative groupoids and commutative rings. The final chapter poses 52 problems.

  1. Fast Overlapping Group Lasso

    CERN Document Server

    Liu, Jun

    2010-01-01

    The group Lasso is an extension of the Lasso for feature selection on (predefined) non-overlapping groups of features. The non-overlapping group structure limits its applicability in practice. There have been several recent attempts to study a more general formulation, where groups of features are given, potentially with overlaps between the groups. The resulting optimization is, however, much more challenging to solve due to the group overlaps. In this paper, we consider the efficient optimization of the overlapping group Lasso penalized problem. We reveal several key properties of the proximal operator associated with the overlapping group Lasso, and compute the proximal operator by solving the smooth and convex dual problem, which allows the use of the gradient descent type of algorithms for the optimization. We have performed empirical evaluations using the breast cancer gene expression data set, which consists of 8,141 genes organized into (overlapping) gene sets. Experimental results demonstrate the eff...

  2. Multicultural group work

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2014-01-01

    Motivation for the activity I use this strategy for forming groups to ensure diverse/multicultural groups that combine a variety of different strengths and resources based on student's academic, disciplinary, linguistic, national, personal and work backgrounds....

  3. Group B streptococcus - pregnancy

    Science.gov (United States)

    Group B streptococcus (GBS) is a type of bacteria that some women carry in their intestines and ... Mosby; 2015:chap 55. Pannaraj PS, Baker CJ. Group B streptococcal infections. In: Cherry J, Harrison GJ, ...

  4. Group Decision Process Support

    DEFF Research Database (Denmark)

    Gøtze, John; Hijikata, Masao

    1997-01-01

    Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists.......Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists....

  5. Group B streptococcus - pregnancy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000511.htm Group B streptococcus - pregnancy To use the sharing features on this page, please enable JavaScript. Group B streptococcus (GBS) is a type of bacteria that ...

  6. SUPPORT GROUPS IN ICEHEARTS

    OpenAIRE

    Cacho, Corey

    2016-01-01

    ABSTRACT Cacho, Corey Support groups in Icehearts. 33 p., 0 appendices. Language: English. Spring 2016. Diaconia University of Applied Sciences. Degree Programme in Social Services, Bachelor of Social Services. The purpose of my thesis is to provide a social support group model for the employees of Icehearts. The social support group model covers the mental health and wellbeing of the employees. The aim of the support group model is to give the employees a creative way of ...

  7. Group Wage Curves

    OpenAIRE

    Bartik, Timothy J.

    2000-01-01

    Using panel data on U.S. MSAs, this paper estimates how a typical MSA's wages of different demographic groups, and prices, are affected by overall MSA unemployment, the distribution of unemployment among different groups, and national prices and wages. MSA unemployment has strong effects on MSA wages and prices, but the distribution of unemployment among different groups has weak effects on wages and prices. Using these estimates, simulations show that targeting high-unemployment groups for u...

  8. Introduction to quantum groups

    OpenAIRE

    Podles, P.; Muller, E.

    1997-01-01

    We give an elementary introduction to the theory of algebraic and topological quantum groups (in the spirit of S. L. Woronowicz). In particular, we recall the basic facts from Hopf (*-) algebra theory, theory of compact (matrix) quantum groups and the theory of their actions on compact quantum spaces. We also provide the most important examples, including the classification of quantum SL(2)-groups, their real forms and quantum spheres. We also consider quantum SL_q(N)-groups and quantum Loren...

  9. Graphical Cyclic Permutation Groups

    OpenAIRE

    Grech, Mariusz

    2012-01-01

    We establish conditions for a permutation group generated by a single permutation of a prime power order to be an automorphism group of a graph or an edge-colored graph. This corrects and generalizes the results of the two papers on cyclic permutation groups published in 1978 and 1981 by S. P. Mohanty, M. R. Sridharan, and S. K. Shukla.

  10. Change through Group Work.

    Science.gov (United States)

    McAllan, Les; Friedman, Amy; Spears, Evans

    Perhaps the most well known treatment modalities in the field of prevention and treatment of addiction are groups. Group settings serve to bring individuals with addictions together at one time in one place to work on relevant issues together. Groups may serve as a safe environment for learning new social and relationship skills, gaining…

  11. AREVA group overview

    International Nuclear Information System (INIS)

    This document presents the Group Areva, a world nuclear industry leader, from a financial holding company to an industrial group, operating in two businesses: the nuclear energy and the components. The structure and the market of the group are discussed, as the financial assets. (A.L.B.)

  12. Groups, combinatorics and geometry

    CERN Document Server

    Ivanov, A A; Saxl, J

    2003-01-01

    Over the past 20 years, the theory of groups in particular simplegroups, finite and algebraic has influenced a number of diverseareas of mathematics. Such areas include topics where groups have beentraditionally applied, such as algebraic combinatorics, finitegeometries, Galois theory and permutation groups, as well as severalmore recent developments.

  13. Microscopic group constants determination

    International Nuclear Information System (INIS)

    The method of microscopic group constants determination for nuclear reactor calculations is described in this paper. The principle of this method is group averaging of microscopic cross sections with respect to the standard spectrum. The group cross sections obtained are used for the calculation of fast critical assembly Jezebel. (author)

  14. Group I intron ribozymes

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2012-01-01

    Group I intron ribozymes constitute one of the main classes of ribozymes and have been a particularly important model in the discovery of key concepts in RNA biology as well as in the development of new methods. Compared to other ribozyme classes, group I intron ribozymes display considerable...... intronic products of these pathways have the potential to integrate into targets and to form various types of circular RNA molecules. Thus, group I intron ribozymes and associated elements found within group I introns is a rich source of biological phenomena. This chapter provides a strategy and protocols...... for initial characterization of new group I intron ribozymes....

  15. Group theory I essentials

    CERN Document Server

    Milewski, Emil G

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Group Theory I includes sets and mapping, groupoids and semi-groups, groups, isomorphisms and homomorphisms, cyclic groups, the Sylow theorems, and finite p-groups.

  16. Splittings of knot groups

    OpenAIRE

    Friedl, Stefan; Silver, Daniel S.; Williams, Susan G.

    2013-01-01

    Let K be a knot of genus g. If K is fibered, then it is well known that the knot group pi(K) splits only over a free group of rank 2g. We show that if K is not fibered, then pi(K) splits over non-free groups of arbitrarily large rank. Furthermore, if K is not fibered, then pi(K) splits over every free group of rank at least 2g. However, pi(K) cannot split over a group of rank less than 2g. The last statement is proved using the recent results of Agol, Przytycki-Wise and Wise.

  17. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, MY); Watkins, Ronnie Wade (Cypress, TX)

    2010-11-09

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  18. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, ML); Watkins, Ronnie Wade (Cypress, TX)

    2012-07-31

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  19. CHAOTIC GROUP ACTIONS

    Institute of Scientific and Technical Information of China (English)

    ShiEnhui; ZhouLizhen; ZhouYoucheng

    2003-01-01

    It is proved that there is no chaotic group actions on any topological space with free arc.In this paper the chaotic actions of the group like G×F,where F is a finite group,are studied.In particular,under a suitable assumption ,if F is a cyclic group,then the topological space which admits a chaotic action of Z×F must admit a chatotic homeomorphism.A topological space which admits a chaotic group action but admits no chaotic horneomorphism is constructed.

  20. On -nilpotent abelian groups

    Indian Academy of Sciences (India)

    Mohammad Mehdi Nasrabadi; Ali Gholamian

    2014-11-01

    Let be a group and $A = \\text{Aut}(G)$ be the group of automorphisms of . Then, the element $[g, ] = g^{-1}(g)$ is an autocommutator of $g \\in G$ and $ \\in A$. Hence, for any natural number the -th autocommutator subgroup of is defined as $K_{m}(G)=\\langle [g,_{1},\\ldots,_{m}]|g\\in G,_{1},\\ldots,_{m}\\in A\\rangle$, where $[g, _{1}, _{2},\\ldots, _{m}] = [[g,_{1},\\ldots,_{m−1}], _{m}]$. In this paper, we introduce the new notion of -nilpotent groups and classify all abelian groups which are -nilpotent groups.

  1. Perfect numbers and groups

    OpenAIRE

    Leinster, Tom

    2001-01-01

    A number is perfect if it is the sum of its proper divisors; here we call a finite group `perfect' if its order is the sum of the orders of its proper normal subgroups. (This conflicts with standard terminology but confusion should not arise.) The notion of perfect group generalizes that of perfect number, since a cyclic group is perfect exactly when its order is perfect. We show that, in fact, the only abelian perfect groups are the cyclic ones, and exhibit some non-abelian perfect groups of...

  2. Group Psychotherapy in Denmark.

    Science.gov (United States)

    Jørgensen, Lars Bo; Thygesen, Bente; Aagaard, Søren

    2015-10-01

    This is a short article on the history and training standards in the Institute of Group Analysis in Copenhagen (IGA-CPH). We describe theoretical orientations and influences in the long-term training program and new initiatives, like courses in mentalization-based group treatment and a dynamic short-term group therapy course, as well as research in group psychotherapy in Denmark. Some group analytic initiatives in relation to social issues and social welfare are presented, as well as initiatives concerning the school system and unemployment. PMID:26401798

  3. E-groups training

    CERN Multimedia

    HR Department

    2012-01-01

    There will be an e-groups training course on 16 March 2012 which will cover the main e-groups functionalities i.e.: creating and managing e-groups, difference between static and dynamic e-groups, configuring posting restrictions and archives, examples of where e-groups can be used in daily work. Even if you have already worked with e-groups, this may be a good opportunity to learn about the best practices and security related recommendations when using e-groups. You can find more details as well as enrolment form for the training (it’s free) here. The number of places is limited, so enrolling early is recommended.   Technical Training Tel. 72844

  4. Toleration, Groups, and Multiculturalism

    DEFF Research Database (Denmark)

    Lægaard, Sune

    The chapter considers how groups might be relevant as objects of policies of toleration and the different senses 'group' might have in relation to questions of toleration. The chapter argues that groups can be relevant to toleration in several different ways as objects of toleration. Toleration is...... routinely defined as involving an objection component, a power requirement and an acceptance component. The objection and acceptance components refer to reasons or dispositions of the subjects of toleration, e.g. public authorities deciding how to act in relation to groups. The power condition refers to the...... toleration allows receivers of toleration to enjoy. The chapter shows how groups may be objects of toleration in different ways in relation to each of these components or conditions of toleration. The sense of 'group' relevant to toleration may differ when the group is an object of power, i.e. when others...

  5. Alternatives for pseudofinite groups

    CERN Document Server

    Houcine, Abderezak Ould

    2012-01-01

    The famous Tits' alternative states that a linear group either contains a nonabelian free group or is soluble-by-(locally finite). We study in this paper similar alternatives in pseudofinite groups. We show for instance that an $\\aleph_{0}$-saturated pseudofinite group either contains a subsemigroup of rank $2$ or is nilpotent-by-(uniformly locally finite). We call a class of finite groups $G$ weakly of bounded rank if the radical $rad(G)$ has a bounded Pr\\"ufer rank and the index of the sockel of $G/rad(G)$ is bounded. We show that an $\\aleph_{0}$-saturated pseudo-(finite weakly of bounded rank) group either contains a nonabelian free group or is nilpotent-by-abelian-by-(uniformly locally finite). We also obtain some relations between this kind of alternatives and amenability.

  6. Group Psychotherapy in Italy.

    Science.gov (United States)

    Giannone, Francesca; Giordano, Cecilia; Di Blasi, Maria

    2015-10-01

    This article describes the history and the prevailing orientations of group psychotherapy in Italy (psychoanalytically oriented, psychodrama, CBT groups) and particularly group analysis. Provided free of charge by the Italian health system, group psychotherapy is growing, but its expansion is patchy. The main pathways of Italian training in the different group psychotherapy orientations are also presented. Clinical-theoretical elaboration on self development, psychopathology related to group experiences, and the methodological attention paid to objectives and methods in different clinical groups are issues related to group therapy in Italy. Difficulties in the relationship between research and clinical practice are discussed, as well as the empirical research network that tries to bridge the gap between research and clinical work in group psychotherapy. The economic crisis in Italy has led to massive cuts in health care and to an increasing demand for some forms of psychological treatment. For these reasons, and because of its positive cost-benefit ratio, group psychotherapy is now considered an important tool in the national health care system to expand the clinical response to different forms of psychological distress. PMID:26401793

  7. Blood groups systems

    Directory of Open Access Journals (Sweden)

    Ranadhir Mitra

    2014-01-01

    Full Text Available International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importance to prevent transfusion-related complications. Nonetheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system.

  8. Blood groups systems.

    Science.gov (United States)

    Mitra, Ranadhir; Mishra, Nitasha; Rath, Girija Prasad

    2014-09-01

    International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importance to prevent transfusion-related complications. Nonetheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system. PMID:25535412

  9. Stochastic Lie group integrators

    CERN Document Server

    Malham, Simon J A

    2007-01-01

    We present Lie group integrators for nonlinear stochastic differential equations with non-commutative vector fields whose solution evolves on a smooth finite dimensional manifold. Given a Lie group action that generates transport along the manifold, we pull back the stochastic flow on the manifold to the Lie group via the action, and subsequently pull back the flow to the corresponding Lie algebra via the exponential map. We construct an approximation to the stochastic flow in the Lie algebra via closed operations and then push back to the Lie group and then to the manifold, thus ensuring our approximation lies in the manifold. We call such schemes stochastic Munthe-Kaas methods after their deterministic counterparts. We also present stochastic Lie group integration schemes based on Castell--Gaines methods. These involve using an underlying ordinary differential integrator to approximate the flow generated by a truncated stochastic exponential Lie series. They become stochastic Lie group integrator schemes if...

  10. Presentations of groups

    CERN Document Server

    Johnson, D L

    1997-01-01

    The aim of this book is to provide an introduction to combinatorial group theory. Any reader who has completed first courses in linear algebra, group theory and ring theory will find this book accessible. The emphasis is on computational techniques but rigorous proofs of all theorems are supplied. This new edition has been revised throughout, including new exercises and an additional chapter on proving that certain groups are infinite.

  11. Group Problem Solving

    CERN Document Server

    Laughlin, Patrick R

    2011-01-01

    Experimental research by social and cognitive psychologists has established that cooperative groups solve a wide range of problems better than individuals. Cooperative problem solving groups of scientific researchers, auditors, financial analysts, air crash investigators, and forensic art experts are increasingly important in our complex and interdependent society. This comprehensive textbook--the first of its kind in decades--presents important theories and experimental research about group problem solving. The book focuses on tasks that have demonstrably correct solutions within mathematical

  12. Blood groups systems

    OpenAIRE

    Ranadhir Mitra; Nitasha Mishra; Girija Prasad Rath

    2014-01-01

    International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importa...

  13. Incentives and group identity

    OpenAIRE

    MASELLA, Paolo; Meier, Stephan; Zahn, Philipp

    2012-01-01

    This paper investigates in a principal-agent environment whether and how group membership influences the effectiveness of incentives and when incentives can have “hidden costs”, i.e., a detrimental effect. We show experimentally that in all interactions control mechanisms can have hidden costs for reasons specific to group membership. In within-group interactions control has detrimental effects because the agent does not expect to be controlled and reacts negatively when being controlled. In ...

  14. Group therapy for adolescents

    OpenAIRE

    Nada Hribar

    2001-01-01

    The group included adolescents from secondary school and some students. The group had weekly sessions or twice on mounth. The adolescents had varied simptoms: depressive, anxiety, psychosomatic disorders, learning difficulties, cunduct problems. All of adolescents were common on many problems in social interactions. The goal of therapeutic work were: to increase assertiveness skills and to reduce the anxious in social situations. The adolescents in group raised a self-esteem and developed som...

  15. Bayesian Group Factor Analysis

    OpenAIRE

    Virtanen, Seppo; Klami, Arto; Khan, Suleiman A; Kaski, Samuel

    2011-01-01

    We introduce a factor analysis model that summarizes the dependencies between observed variable groups, instead of dependencies between individual variables as standard factor analysis does. A group may correspond to one view of the same set of objects, one of many data sets tied by co-occurrence, or a set of alternative variables collected from statistics tables to measure one property of interest. We show that by assuming group-wise sparse factors, active in a subset of the sets, the variat...

  16. Semisimple Metacyclic Group Algebras

    Indian Academy of Sciences (India)

    Gurmeet K Bakshi; Shalini Gupta; Inder Bir S Passi

    2011-11-01

    Given a group of order $p_1p_2$, where $p_1,p_2$ are primes, and $\\mathbb{F}_q$, a finite field of order coprime to $p_1p_2$, the object of this paper is to compute a complete set of primitive central idempotents of the semisimple group algebra $\\mathbb{F}_q[G]$. As a consequence, we obtain the structure of $\\mathbb{F}_q[G]$ and its group of automorphisms.

  17. Explosive Technology Group

    Data.gov (United States)

    Federal Laboratory Consortium — The Explosive Technology Group (ETG) provides diverse technical expertise and an agile, integrated approach to solve complex challenges for all classes of energetic...

  18. Factoring groups into subsets

    CERN Document Server

    Szabo, Sandor

    2009-01-01

    Decomposing an abelian group into a direct sum of its subsets leads to results that can be applied to a variety of areas, such as number theory, geometry of tilings, coding theory, cryptography, graph theory, and Fourier analysis. Focusing mainly on cyclic groups, Factoring Groups into Subsets explores the factorization theory of abelian groups. The book first shows how to construct new factorizations from old ones. The authors then discuss nonperiodic and periodic factorizations, quasiperiodicity, and the factoring of periodic subsets. They also examine how tiling plays an important role in n

  19. Study Groups in Denmark

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions.......Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  20. Lie groups for pedestrians

    CERN Document Server

    Lipkin, Harry J

    2002-01-01

    According to the author of this concise, high-level study, physicists often shy away from group theory, perhaps because they are unsure which parts of the subject belong to the physicist and which belong to the mathematician. However, it is possible for physicists to understand and use many techniques which have a group theoretical basis without necessarily understanding all of group theory. This book is designed to familiarize physicists with those techniques. Specifically, the author aims to show how the well-known methods of angular momentum algebra can be extended to treat other Lie group

  1. Antilipide antibodies cofactor in syphilis, Lyme borreliosis and autoimmune diseases

    OpenAIRE

    B Voicechovskaya; J Zabek

    2003-01-01

    Objective. To study (32 glycoprotein 1 contribution to frequency of aCL in pts with autoimmune and some infectious diseases. Methods. Antibodies to different phospholipids were tested by immune-enzyme method (IEM) in serum of 92 pts: 20 of them had systemic lupus erythematosus (SLE), 15 Sjogren’s disease (SD), 20 rheumatoid arthritis (RA), 20 syphilis and 17 Lyme disease (LD). Pts with syphilis and LD did not have clinical signs of autoimmune disease. Stimulation of aCL test in IEM was perfor...

  2. Meningoradiculitis due to borreliosis presenting as low back pain only

    International Nuclear Information System (INIS)

    We report a child with Borrelia burgdorferi meningoradiculitis. This entity, also known as Bannwarth syndrome, is rare and its presentation with low back pain only is even more unusual. The MRI findings can suggest the diagnosis. (orig.)

  3. Epidemiology of tick-borne borreliosis in Morocco.

    Directory of Open Access Journals (Sweden)

    Georges Diatta

    Full Text Available BACKGROUND: The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. METHODOLOGY/PRINCIPAL FINDINGS: Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF in febrile patients in Kenitra district. The prevalence of Borrelia infections was assessed by nested PCR amplification in ticks and the brain tissue of small mammals, and by evaluation of thick blood films in patients. A high proportion of burrows were infested with ticks of the O. erraticus complex in all regions of Morocco, with a mean of 39.5% for the whole country. Borrelia infections were found in 39/382 (10.2% of the ticks and 12/140 (8.6% of the rodents and insectivores studied by PCR amplification, and 102 patients tested positive by thick blood film. Five small mammalian species were found infected: Dipodillus campestris, Meriones shawi, Gerbillus hoogstrali, Gerbillus occiduus and Atelerix algirus. Three Borrelia species were identified in ticks and/or rodents: B. hispanica, B. crocidurae and B. merionesi. CONCLUSIONS/SIGNIFICANCE: Tick populations belonging to O. erraticus complex are widely distributed in Morocco and a high proportion of ticks and small mammals are infected by Borrelia species. Although rarely diagnosed, TBRF may be a common cause of morbidity in all regions of Morocco.

  4. Epidemiology of tick-borne borreliosis in Morocco

    OpenAIRE

    Diatta, Georges; Souidi, Yassine; Granjon, Laurent; Arnathau, Céline; Durand, Patrick; Chauvancy, Gilles; Mané, Youssouph; Sarih, M'Hammed; BELGHYTI, Driss; Renaud, François; Trape, Jean-François

    2012-01-01

    Background: The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF) in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. Methodology/Principal Findings: Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF ...

  5. Meningoradiculitis due to borreliosis presenting as low back pain only

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P.; Crevits, I.; Baert, A.L. [Department of Radiology, University Hospitals, Leuven (Belgium); Casteels-Van Daele, M. [Department of Paediatrics, University Hospitals, Leuven (Belgium)

    1998-02-01

    We report a child with Borrelia burgdorferi meningoradiculitis. This entity, also known as Bannwarth syndrome, is rare and its presentation with low back pain only is even more unusual. The MRI findings can suggest the diagnosis. (orig.) With 1 fig., 3 refs.

  6. Weyl group invariants

    CERN Document Server

    Kameko, Masaki

    2012-01-01

    For any odd prime $p$, we prove that the induced homomorphism from the mod $p$ cohomology of the classifying space of a compact simply-connected simple connected Lie group to the Weyl group invariants of the mod $p$ cohomology of the classifying space of its maximal torus is an epimorphism except for the case $p=3$, $G=E_8$.

  7. Introduction to quantum groups

    International Nuclear Information System (INIS)

    These pedagogical lectures contain some motivation for the study of quantum groups; a definition of ''quasi triangular Hopf algebra'' with explanations of all the concepts required to build it up; descriptions of quantised universal enveloping algebras and the quantum double; and an account of quantised function algebras and the action of quantum groups on quantum spaces. (author)

  8. Topologies on Abelian Groups

    Science.gov (United States)

    Zelenyuk, E. G.; Protasov, I. V.

    1991-04-01

    A filter phi on an abelian group G is called a T-filter if there exists a Hausdorff group topology under which phi converges to zero. G{phi} will denote the group G with the largest topology among those making phi converge to zero. This method of defining a group topology is completely equivalent to the definition of an abstract group by defining relations. We shall obtain characterizations of T-filters and of T-sequences; among these, we shall pay particular attention to T-sequences on the integers. The method of T-sequences will be used to construct a series of counterexamples for several open problems in topological algebra. For instance there exists, on every infinite abelian group, a topology distinguishing between sequentiality and the Fréchet-Urysohn property (this solves a problem posed by V.I. Malykhin) we also find a topology on the group of integers admitting no nontrivial continuous character, thus solving a problem of Nienhuys. We show also that on every infinite abelian group there exists a free ultrafilter which is not a T-ultrafilter.

  9. Study Groups in Denmark

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  10. Natural analogue working group

    International Nuclear Information System (INIS)

    A Natural Analogue Working Group was established by the Commission of the European Communities in 1985. The purpose of this group is to bring together modellers with earth scientists and others, so that maximum benefit can be obtained from natural analogue studies with a view to safe geological disposal of radioactive waste. The first meeting of this group was held in Brussels from November 5 to 7, 1985. The discussions mainly concerned the identification of the modellers' needs and of the earth scientists' capacity to provide for them. Following the debates, a written statement was produced by the Group; this document forms the core of the present Report. Notes and outlines of many of the presentations made are grouped in four appendixes. The valuable contribution of all those involved in the meeting is gratefully acknowledged

  11. Isotropy in group cohomology

    DEFF Research Database (Denmark)

    Ben David, Nir; Ginosar, Yuval; Meir, Ehud

    2014-01-01

    The analog of Lagrangians for symplectic forms over finite groups is studied, motivated by the fact that symplectic G  -forms with a normal Lagrangian N◃G  are in one-to-one correspondence, up to inflation, with bijective 1-cocycle data on the quotients G/N  . This yields a method to construct...... groups of central type from such quotients, known as Involutive Yang–Baxter groups. Another motivation for the search of normal Lagrangians comes from a non-commutative generalization of Heisenberg liftings that require normality. Although it is true that symplectic forms over finite nilpotent groups...... always admit Lagrangians, we exhibit an example where none of these subgroups is normal. However, we prove that symplectic forms over nilpotent groups always admit normal Lagrangians if all their p  -Sylow subgroups are of order less than p 8   ....

  12. Cyclic Soft Groups and Their Applications on Groups

    Directory of Open Access Journals (Sweden)

    Hacı Aktaş

    2014-01-01

    Full Text Available In crisp environment the notions of order of group and cyclic group are well known due to many applications. In this paper, we introduce order of the soft groups, power of the soft sets, power of the soft groups, and cyclic soft group on a group. We also investigate the relationship between cyclic soft groups and classical groups.

  13. Polysynovitis in a horse due to [i]Borrelia burgdorferi[/i] sensu lato infection – Case study

    Directory of Open Access Journals (Sweden)

    Fabrizio Passamonti

    2015-05-01

    Full Text Available Lyme borreliosis (LB is a multi-systemic tick-borne disease affecting both humans and animals, including horses, and is caused by a group of interrelated spirochetes classified within the[i] Borrelia burgdorferi [/i]sensu lato (s.l. complex. Despite the high reported seroprevalence in the European equine population for [i]B. burgdorferi[/i] s.l., to-date no documented clinical cases have been described. A 6-year-old Paint gelding was referred with a history of three weeks of fever, intermittent lameness and digital flexor tendon sheath effusion of the right hind limb. Based on a strict diagnostic protocol, which included serological tests for infectious diseases and molecular investigations, a final diagnosis was made of polysynovitis due to [i]B. burgdorferi [/i]s.l. infection. An unreported aspect observed in this case was the absence of the pathogen DNA in two of the affected joints. To the authors’ knowledge, the case described represents the first documented clinical case of equine LB in Italy. Moreover, the absence of pathogen DNA in two of the affected joints observed in this case revealed a possible similarity with the same condition described in humans, where an immunomediated pathogenesis for arthropathy due to [i]B. burgdorferi[/i] s.l. infection is suspected. Since humans and horses share the same habitat, this report supports the role of the horse as potential sentinel for human biological risk.

  14. Critical groups - basic concepts

    International Nuclear Information System (INIS)

    The potential exposure pathways from the land application site to man are presented. It is emphasised that the critical group is not necessary the population group closest to the source. It could be the group impact by the most significant pathways(s). Only by assessing the importance of each of these pathways and then combining them can a proper choice of critical group be made. It would be wrong to select a critical group on the basis that it seems the most probable one, before the pathways have been properly assessed. A calculation in Carter (1983) suggested that for the operating mine site, the annual doses to an Aboriginal person, a service worker and a local housewife, were all about the same and were in the range 0.1 to 0.2 mSv per year. Thus it may be that for the land application area, the critical group turns out to be non-Aboriginal rather than the expected Aboriginal group. 6 refs., 3 figs

  15. Quantum group connections

    OpenAIRE

    Lewandowski, Jerzy; Okolow, Andrzej

    2008-01-01

    The Ahtekar-Isham C*-algebra known from Loop Quantum Gravity is the algebra of continuous functions on the space of (generalized) connections with a compact structure Lie group. The algebra can be constructed by some inductive techniques from the C*-algebra of continuous functions on the group and a family of graphs embedded in the manifold underlying the connections. We generalize the latter construction replacing the commutative C*-algebra of continuous functions on the group by a non-commu...

  16. Group therapy for adolescents

    Directory of Open Access Journals (Sweden)

    Nada Hribar

    2001-03-01

    Full Text Available The group included adolescents from secondary school and some students. The group had weekly sessions or twice on mounth. The adolescents had varied simptoms: depressive, anxiety, psychosomatic disorders, learning difficulties, cunduct problems. All of adolescents were common on many problems in social interactions. The goal of therapeutic work were: to increase assertiveness skills and to reduce the anxious in social situations. The adolescents in group raised a self-esteem and developed some assertiveness skills: eye contact" and effective communication skills, persistence, refusing and requesting, giving and receiving critism, etc. The methods of work and techniques were based on principles of cognitive-behaviour therapy.

  17. Group ring cryptography

    CERN Document Server

    Hurley, Barry

    2011-01-01

    Cryptographic systems are derived using units in group rings. Combinations of types of units in group rings give units not of any particular type. This includes cases of taking powers of units and products of such powers and adds the complexity of the {\\em discrete logarithm} problem to the system. The method enables encryption and (error-correcting) coding to be combined within one system. These group ring cryptographic systems may be combined in a neat way with existing cryptographic systems, such as RSA, and a combination has the combined strength of both systems. Examples are given.

  18. Group key management

    Energy Technology Data Exchange (ETDEWEB)

    Dunigan, T.; Cao, C.

    1997-08-01

    This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.

  19. Homogenous finitary symmetric groups

    Directory of Open Access Journals (Sweden)

    Otto‎. ‎H‎. Kegel

    2015-03-01

    Full Text Available We characterize strictly diagonal type of embeddings of finitary symmetric groups in terms of cardinality and the characteristic. Namely, we prove the following. Let kappa be an infinite cardinal. If G=underseti=1stackrelinftybigcupG i , where G i =FSym(kappan i , (H=underseti=1stackrelinftybigcupH i , where H i =Alt(kappan i , is a group of strictly diagonal type and xi=(p 1 ,p 2 ,ldots is an infinite sequence of primes, then G is isomorphic to the homogenous finitary symmetric group FSym(kappa(xi (H is isomorphic to the homogenous alternating group Alt(kappa(xi , where n 0 =1,n i =p 1 p 2 ldotsp i .

  20. RAS Laboratory Groups

    Science.gov (United States)

    The RAS Initiative uses multiple technologies to attack RAS-driven cancers. The resources of the Frederick National Lab allocated to the RAS Hub are organized into seven laboratory groups, each contributing to the collaborative effort.

  1. Homogeneous group, research, institution

    Directory of Open Access Journals (Sweden)

    Francesca Natascia Vasta

    2014-09-01

    Full Text Available The work outlines the complex connection among empiric research, therapeutic programs and host institution. It is considered the current research state in Italy. Italian research field is analyzed and critic data are outlined: lack of results regarding both the therapeutic processes and the effectiveness of eating disorders group analytic treatment. The work investigates on an eating disorders homogeneous group, led into an eating disorder outpatient service. First we present the methodological steps the research is based on including the strong connection among theory and clinical tools. Secondly clinical tools are described and the results commented. Finally, our results suggest the necessity of validating some more specifical hypothesis: verifying the relationship between clinical improvement (sense of exclusion and painful emotions reduction and specific group therapeutic processes; verifying the relationship between depressive feelings, relapses and transition trough a more differentiated groupal field.Keywords: Homogeneous group; Eating disorders; Institutional field; Therapeutic outcome

  2. Group Support Systems (GSS)

    Science.gov (United States)

    Hamel, Gary P.; Wijesinghe, R.

    1996-01-01

    Groupware is a term describing an emerging computer software technology enhancing the ability of people to work together as a group, (a software driven 'group support system'). This project originated at the beginning of 1992 and reports were issued describing the activity through May 1995. These reports stressed the need for process as well as technology. That is, while the technology represented a computer assisted method for groups to work together, the Group Support System (GSS) technology als required an understanding of the facilitation process electronic meetings demand. Even people trained in traditional facilitation techniques did not necessarily aimlessly adopt groupware techniques. The latest phase of this activity attempted to (1) improve the facilitation process by developing training support for a portable groupware computer system, and (2) to explore settings and uses for the portable groupware system using different software, such as Lotus Notes.

  3. UnitedHealth Group

    Science.gov (United States)

    UnitedHealth Group provides accessible and affordable services, improved quality of care, coordinated health care efforts, and a supportive environment for shared decision making between patients and their physicians.

  4. Groups – Additive Notation

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-06-01

    Full Text Available We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  5. Radiation Protection Group

    CERN Multimedia

    2006-01-01

    The Radioactive Waste Section of the Radiation Protection Group wishes to inform you that the Radioactive Waste Treatment Centre will be closed on the afternoon of Tuesday 19 December 2006. Thank-you for your understanding.

  6. Anxiety Disorders: Support Groups

    Science.gov (United States)

    ... Guidelines Scientific Council Special Interest Groups Child & Adolescent Anxiety SIG Peer Consultation OCD & Related Disorders SIG Peer ... Jobs and Fellowships Journal & Multimedia Announcements Depression and Anxiety Podcasts & Videos Resources Clinical Practice Reviews & Teaching Tools ...

  7. Group Capability Model

    Science.gov (United States)

    Olejarski, Michael; Appleton, Amy; Deltorchio, Stephen

    2009-01-01

    The Group Capability Model (GCM) is a software tool that allows an organization, from first line management to senior executive, to monitor and track the health (capability) of various groups in performing their contractual obligations. GCM calculates a Group Capability Index (GCI) by comparing actual head counts, certifications, and/or skills within a group. The model can also be used to simulate the effects of employee usage, training, and attrition on the GCI. A universal tool and common method was required due to the high risk of losing skills necessary to complete the Space Shuttle Program and meet the needs of the Constellation Program. During this transition from one space vehicle to another, the uncertainty among the critical skilled workforce is high and attrition has the potential to be unmanageable. GCM allows managers to establish requirements for their group in the form of head counts, certification requirements, or skills requirements. GCM then calculates a Group Capability Index (GCI), where a score of 1 indicates that the group is at the appropriate level; anything less than 1 indicates a potential for improvement. This shows the health of a group, both currently and over time. GCM accepts as input head count, certification needs, critical needs, competency needs, and competency critical needs. In addition, team members are categorized by years of experience, percentage of contribution, ex-members and their skills, availability, function, and in-work requirements. Outputs are several reports, including actual vs. required head count, actual vs. required certificates, CGI change over time (by month), and more. The program stores historical data for summary and historical reporting, which is done via an Excel spreadsheet that is color-coded to show health statistics at a glance. GCM has provided the Shuttle Ground Processing team with a quantifiable, repeatable approach to assessing and managing the skills in their organization. They now have a common

  8. Genomics Research Group Session

    OpenAIRE

    Baldwin, D.; Chittur, S.V.; Raghavachari, N.; N Jafari; Aquino, C.; Perera, A; Reyero, N.G.

    2014-01-01

    The Genomics Research Group (GRG) presentation is intended to describe the current activities of the group in applying the latest tools and technologies for transcriptome analysis to determine the advantages and disadvantages of each of the platforms. We will present three ongoing projects. In the first project, we specifically evaluated microarrays, QPCR and Next Generation Sequencing (NGS) platforms for examining the sensitivity and specificity of microRNA detection using synthetic miRNA st...

  9. Reactivity of nitrosyl group

    International Nuclear Information System (INIS)

    Reactivity of ruthenium nitrosyl complexes is considered. According to X-ray structure analysis data nitrogen oxide interaction with metals results in formation of two complexes. The first ones contain linear nitrosyls (valence bond angle 180 deg in M-NO grouping), the second ones - bend nitrosyls (the bond angle in M-N-O grouping 120-130 deg). The first type complexes react primarily with nucleophilic reagents (OH-, N3-), the second ones - with electrophilic reagents

  10. Introduction to group theory

    Directory of Open Access Journals (Sweden)

    Canals B.

    2012-03-01

    Full Text Available This chapter is a concise mathematical introduction into the algebra of groups. It is build up in the way that definitions are followed by propositions and proofs. The concepts and the terminology introduced here will serve as a basis for the following chapters that deal with group theory in the stricter sense and its application to problems in physics. The mathematical prerequisites are at the bachelor level.1

  11. Arithmetic Cohomology Groups

    OpenAIRE

    Sugahara, K.; Weng, L

    2015-01-01

    We first introduce global arithmetic cohomology groups for quasi-coherent sheaves on arithmetic varieties, adopting an adelic approach. Then, we establish fundamental properties, such as topological duality and inductive long exact sequences, for these cohomology groups on arithmetic surfaces. Finally, we expose basic structures for ind-pro topologies on adelic spaces of arithmetic surfaces. In particular, we show that these adelic spaces are topologically self-dual.

  12. Fuzzy Soft Topological Groups

    Directory of Open Access Journals (Sweden)

    S. Nazmul

    2014-03-01

    Full Text Available Notions of Lowen type fuzzy soft topological space are introduced and some of their properties are established in the present paper. Besides this, a combined structure of a fuzzy soft topological space and a fuzzy soft group, which is termed here as fuzzy soft topological group is introduced. Homomorphic images and preimages are also examined. Finally, some definitions and results on fuzzy soft set are studied.

  13. Email Grouping Method

    OpenAIRE

    Taiwo Ayodele; Shikun Zhou; Rinat Khusainov

    2010-01-01

    In this paper we presents a neural network based system for automated email grouping into activities found in the email message- Email Grouping Method (EGM). Email users spend a lot of time reading, replying and organizing their emails and this seems to be time consuming and sometimes can resolves to less performance of daily duty, and un-necessary distractions. A new system that can manage mails on our behalf is required. EGM is developed to help organise email messages, intelligently struct...

  14. Membership in citizen groups

    OpenAIRE

    Barbieri, Stefano; Mattozzi, Andrea

    2009-01-01

    We analyze the coordination problem of agents deciding to join a group that uses membership revenues to provide a discrete public good and excludable benefits. The public good and the benefits are jointly produced, so that benefits are valued only if the group succeeds in providing the public good. With asymmetric information about the cost of provision, the static membership game admits a unique equilibrium and we characterize the optimal membership fee. We show that heterogeneity in valuati...

  15. Group Factor Analysis

    OpenAIRE

    Klami, Arto; Virtanen, Seppo; Leppäaho, Eemeli; Kaski, Samuel

    2014-01-01

    Factor analysis provides linear factors that describe relationships between individual variables of a data set. We extend this classical formulation into linear factors that describe relationships between groups of variables, where each group represents either a set of related variables or a data set. The model also naturally extends canonical correlation analysis to more than two sets, in a way that is more flexible than previous extensions. Our solution is formulated as variational inferenc...

  16. Interocular grouping without awareness.

    Science.gov (United States)

    Lin, San-Yuan; Yeh, Su-Ling

    2016-04-01

    Interocular grouping occurs when different parts of an image presented to each eye bound into a coherent whole. Previous studies anticipated that these parts are visible to both eyes simultaneously (i.e., the images altered back and forth). Although this view is consistent with the general consensus of binocular rivalry (BR) that suppressed stimuli receive no processing beyond rudimentary level (i.e., adaptation), it is actually inconsistent with studies that use continuous flash suppression (CFS). CFS is a form of interocular suppression that is more stable and causes stronger suppression of stimuli than BR. In the present study, we examined whether or not interocular grouping needs to occur at a conscious level as prior studies suggested. The modified double-rectangle paradigm used by Egly, Driver, and Rafal (1994) was adopted, and object-based attention was directed for successful grouping. To induce interocular grouping, we presented complementary parts of two rectangles dichoptically for possible interocular grouping and a dynamic Mondrian in front of one eye (i.e., CFS). Two concurrent targets were presented after one of the visible parts of the rectangles was cued. Participants were asked to judge which target appeared first. We found that the target showed on the cued rectangle after interocular grouping was reported to appear first more frequently than the target on the uncued rectangle. This result was based on the majority of trials where the suppressed parts of the objects remained invisible, which indicates that interocular grouping can occur without all the to-be-grouped parts being visible and without awareness. PMID:26851342

  17. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  18. N-ary Groups

    CERN Document Server

    Gal'mak, Alexander M

    2011-01-01

    The book "N-ary Groups" (in Russian) consists of two Parts. It is intended on the one hand as an initial introduction to the theory of n-ary groups, and on the other hand it contains the published results by the author on this subject. At present, the theory of n-ary groups developing but slowly from group theory. Nonetheless, ternary and n-ary structures have recently been applied to modern models of elementary particle physics. One of the author's goals in this book is to draw the attention of mathematicians and theoretical physicists to the theory of n-ary groups, to some of its distinguishing features, and to details relevant to its further development and application. Part I: Theorems of Post and Gluskin-Hosszu. 1.1. Classical definitions of n-ary groups. Examples. 1.2. Analogies of identity and inverse elements. 1.3. Equivalent sequences. 1.4. Post's coset theorem. 1.5. Theorem of Gluskin-Hosszu. 1.6. Connection between the Post's coset theorem and theorem of Gluskin-Hosszu. Addition and comments. Part ...

  19. Group 2. Grouting

    International Nuclear Information System (INIS)

    This paper summarizes the findings of the Grouting Working Group which met during the Workshop on Radioactive, Hazardous, and/or Mixed Waste Sludge Management. The scope of this working group was to identify issues related to laboratory-scale experimentation in support of operation and design of an actual plant. The group recognizes that several stabilization/solidification (S/S) host media are available and, whichever is chosen, must be proven appropriate for the specific disposal scenario. However, the group focused on developing a systematic approach for the selection of cement-based grouting as an option, because of the prevalence of its application. It should be recognized that many of the issues will be generic to any stabilization process. Prior to the workshop, this group's members identified over 30 issues for discussion. At a previous informal session, the group distilled these to four issues that are believed to be at the heart of the 30 considered. The four issues were: (1) that both standard and site process-specific performance criteria must be identified, (2) that the waste-binder chemical interactions and the subsequent effect of these interactions on the chemical and physical properties of the resulting waste form must be better understood, (3) that scale-up factors must be considered in order to improve the probability of successfully developing waste-form products, and (4) that if S/S technology is to remain a widely used treatment option, product quality and performance must be confirmed over time

  20. Independents' group posts loss

    International Nuclear Information System (INIS)

    Low oil gas prices and special charges caused the group of 50 U.S. independent producers Oil and Gas Journal tracks to post a combined loss in first half 1992. The group logged a net loss of $53 million in the first half compared with net earnings of $354 million in first half 1991, when higher oil prices during the Persian Gulf crisis buoyed earnings in spite of crude oil and natural gas production declines. The combined loss in the first half follows a 45% drop in the group's earnings in 1991 and compares with the OGJ group of integrated oil companies whose first half 1992 income fell 47% from the prior year. Special charges, generally related to asset writedowns, accounted for most of the almost $560 million in losses posted by about the third of the group. Nerco Oil and Gas Inc., Vancouver, Wash., alone accounted for almost half that total with charges related to an asset writedown of $238 million in the first quarter. Despite the poor first half performance, the outlook is bright for sharply improved group earnings in the second half, assuming reasonably healthy oil and gas prices and increased production resulting from acquisitions and in response to those prices

  1. Coordinating Group report

    International Nuclear Information System (INIS)

    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup

  2. Facilities removal working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This working group`s first objective is to identify major economic, technical, and regulatory constraints on operator practices and decisions relevant to offshore facilities removal. Then, the group will try to make recommendations as to regulatory and policy adjustments, additional research, or process improvements and/or technological advances, that may be needed to improve the efficiency and effectiveness of the removal process. The working group will focus primarily on issues dealing with Gulf of Mexico platform abandonments. In order to make the working group sessions as productive as possible, the Facilities Removal Working Group will focus on three topics that address a majority of the concerns and/or constraints relevant to facilities removal. The three areas are: (1) Explosive Severing and its Impact on Marine Life, (2) Pile and Conductor Severing, and (3) Deep Water Abandonments This paper will outline the current state of practice in the offshore industry, identifying current regulations and specific issues encountered when addressing each of the three main topics above. The intent of the paper is to highlight potential issues for panel discussion, not to provide a detailed review of all data relevant to the topic. Before each panel discussion, key speakers will review data and information to facilitate development and discussion of the main issues of each topic. Please refer to the attached agenda for the workshop format, key speakers, presentation topics, and panel participants. The goal of the panel discussions is to identify key issues for each of the three topics above. The working group will also make recommendations on how to proceed on these key issues.

  3. Linear algebraic groups

    CERN Document Server

    Springer, T A

    1998-01-01

    "[The first] ten chapters...are an efficient, accessible, and self-contained introduction to affine algebraic groups over an algebraically closed field. The author includes exercises and the book is certainly usable by graduate students as a text or for self-study...the author [has a] student-friendly style… [The following] seven chapters... would also be a good introduction to rationality issues for algebraic groups. A number of results from the literature…appear for the first time in a text." –Mathematical Reviews (Review of the Second Edition) "This book is a completely new version of the first edition. The aim of the old book was to present the theory of linear algebraic groups over an algebraically closed field. Reading that book, many people entered the research field of linear algebraic groups. The present book has a wider scope. Its aim is to treat the theory of linear algebraic groups over arbitrary fields. Again, the author keeps the treatment of prerequisites self-contained. The material of t...

  4. Borrelia burgdorferi strain-specific Osp C-mediated immunity in mice.

    Science.gov (United States)

    Bockenstedt, L K; Hodzic, E; Feng, S; Bourrel, K W; de Silva, A; Montgomery, R R; Fikrig, E; Radolf, J D; Barthold, S W

    1997-11-01

    Antibodies to the outer surface proteins (Osps) A, B, and C of the spirochete Borrelia burgdorferi can prevent infection in animal models of Lyme borreliosis. We have previously demonstrated that immune serum from mice infected with B. burgdorferi N40 can also prevent challenge infection and induce disease regression in infected mice. The antigens targeted by protective and disease-modulating antibodies are presently unknown, but they do not include Osp A or Osp B. Because Osp C antibodies are present in immune mouse serum, we investigated the ability of hyperimmune serum to recombinant Osp C (N40) to protect mice against challenge infection with N40 spirochetes. In both active and passive immunization studies, Osp C (N40) antiserum failed to protect mice from challenge infection with cultured organisms. Mice actively immunized with recombinant Osp C (N40) were susceptible to tick-borne challenge infection, and nymphal ticks remained infected after feeding on Osp C-hyperimmunized mice. In contrast, similar immunization studies performed with Osp C (PKo) antiserum prevented challenge infection of mice with a clone of PKo spirochetes pathogenic for mice. Both Osp C (N40) and Osp C (PKo) antisera showed minimal in vitro borreliacidal activity, and immunofluorescence studies localized Osp C beneath the outer membrane of both N40 and PKo spirochetes. We conclude that Osp C antibody-mediated immunity is strain specific and propose that differences in Osp C surface expression by spirochetes in vivo may account for strain-specific immunity. PMID:9353047

  5. Illinois Wind Workers Group

    Energy Technology Data Exchange (ETDEWEB)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  6. Financial Lie groups

    CERN Document Server

    carfí, David

    2011-01-01

    In this paper we see the evolution of a capitalized financial event e, with respect to a capitalization factor f, as the exponential map of a suitably defined Lie group G(f,e), supported by the half-space of capitalized financial events having the same capital sign of e. The Lie group G(f,e) depends upon the capitalization factor f and on the event e itself. After the extension of the definition of exponential map of a Lie group, we shall eliminate the dependence on the financial event e, recognizing the presence of essentially one unique financial Lie semigroup, supported by the entire space of capitalized financial events, determined by the capitalization factor f.

  7. Instructions to working groups

    Science.gov (United States)

    Foushee, H. Clayton

    1987-01-01

    The key to the success of this workshop is your active participation in the working group process. The goals of this workshop are to address four major questions regarding Cockpit Resource Management (CRM) Training. To some extent the working group topic areas parallel these issues, but in some cases they do not. However, it is important for all of the working groups to keep these general questions in mind during their deliberations: (1) What are the essential elements of an optimal CRM Training program; (2) What are the strengths and weaknesses of current approaches to CRM Training; (3) How can CRM Training best be implemented, and what barriers exist; and (4) Is CRM Training effective, do we know, and if not, how can we find out.

  8. Group Psychotherapy in Sweden.

    Science.gov (United States)

    Ahlin, Göran

    2015-10-01

    The paper presents an overview of the national developments of group psychotherapy (GPS) in Sweden during the period from World War II until the present time. Methods and concepts, imported primarily from England and the United States, inspired trainings and widespread psychodynamic and group analytic applications in schools, health treatment, and social care. Education in psychotherapy and GPS at universities opened new therapeutic and vocational areas during the period 1970-2005. Increasing criticism of psychodynamics, as in other Western societies, but more radical in Sweden, has in the last decades made group analytic GPS diminish in favor of cognitive behavioral therapy models. Prospects for GPS further development may presently look bleak but, in a longer perspective, are promising. PMID:26401795

  9. Quantum threshold group signature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

  10. Focus group discussions

    CERN Document Server

    Hennink, Monique M

    2014-01-01

    The Understanding Research series focuses on the process of writing up social research. The series is broken down into three categories: Understanding Statistics, Understanding Measurement, and Understanding Qualitative Research. The books provide researchers with guides to understanding, writing, and evaluating social research. Each volume demonstrates how research should be represented, including how to write up the methodology as well as the research findings. Each volume also reviews how to appropriately evaluate published research. Focus Group Discussions addresses the challenges associated with conducting and writing focus group research. It provides detailed guidance on the practical and theoretical considerations in conducting focus group discussions including: designing the discussion guide, recruiting participants, training a field team, moderating techniques and ethical considerations. Monique Hennink describes how a methodology section is read and evaluated by others, such as journal reviewers or ...

  11. Colored Group Field Theory

    CERN Document Server

    Gurau, Razvan

    2009-01-01

    Group field theories are higher dimensional generalizations of matrix models. Their Feynman graphs are fat and in addition to vertices, edges and faces, they also contain higher dimensional cells, called bubbles. In this paper, we propose a new, fermionic Group Field Theory, posessing a color symmetry, and take the first steps in a systematic study of the topological properties of its graphs. Unlike its bosonic counterpart, the bubbles of the Feynman graphs of this theory are well defined and readily identified. We prove that this graphs are combinatorial cellular complexes. We define and study the cellular homology of this graphs. Furthermore we define a homotopy transformation appropriate to this graphs. Finally, the amplitude of the Feynman graphs is shown to be related to the fundamental group of the cellular complex.

  12. Supervision and group dynamics

    DEFF Research Database (Denmark)

    Hansen, Søren; Jensen, Lars Peter

    2004-01-01

     An important aspect of the problem based and project organized study at Aalborg University is the supervision of the project groups. At the basic education (first year) it is stated in the curriculum that part of the supervisors' job is to deal with group dynamics. This is due to the experience...... that many students are having difficulties with practical issues such as collaboration, communication, and project management. Most supervisors either ignore this demand, because they do not find it important or they find it frustrating, because they do not know, how to supervise group dynamics. This...... problem is not only found at Aalborg University but also at the engineering colleges in Denmark. For that reason a course was developed with the aim of addressing the problem and showing, how it can be dealt with. So far the course has been offered several times to supervisors at the engineering colleges...

  13. Fourier Analysis on Groups

    CERN Document Server

    Rudin, Walter

    2011-01-01

    In the late 1950s, many of the more refined aspects of Fourier analysis were transferred from their original settings (the unit circle, the integers, the real line) to arbitrary locally compact abelian (LCA) groups. Rudin's book, published in 1962, was the first to give a systematic account of these developments and has come to be regarded as a classic in the field. The basic facts concerning Fourier analysis and the structure of LCA groups are proved in the opening chapters, in order to make the treatment relatively self-contained.

  14. A Quantum Groups Primer

    Science.gov (United States)

    Majid, Shahn

    2002-05-01

    Here is a self-contained introduction to quantum groups as algebraic objects. Based on the author's lecture notes for the Part III pure mathematics course at Cambridge University, the book is suitable as a primary text for graduate courses in quantum groups or supplementary reading for modern courses in advanced algebra. The material assumes knowledge of basic and linear algebra. Some familiarity with semisimple Lie algebras would also be helpful. The volume is a primer for mathematicians but it will also be useful for mathematical physicists.

  15. Group theory and chemistry

    CERN Document Server

    Bishop, David M

    1993-01-01

    Group theoretical principles are an integral part of modern chemistry. Not only do they help account for a wide variety of chemical phenomena, they simplify quantum chemical calculations. Indeed, knowledge of their application to chemical problems is essential for students of chemistry. This complete, self-contained study, written for advanced undergraduate-level and graduate-level chemistry students, clearly and concisely introduces the subject of group theory and demonstrates its application to chemical problems.To assist chemistry students with the mathematics involved, Professor Bishop ha

  16. Hierarchies in student groups

    OpenAIRE

    Güntert, Manuel

    2008-01-01

    This is a research about hierarchies in student groups. It shows how they are built und what sense they have. The position of a student in his student peer group is evaluated. The influence of the look, the style, the behaviour of the other sex, the gender, the origin, the prehistory, the appearance, achievement and their effect on hierarchies is analysed and the impact of charisma and organisation are compared. The meaning of this research is to indicate how a student must be to get the lead...

  17. Bell, group and tangle

    International Nuclear Information System (INIS)

    The 'Bell' of the title refers to bipartite Bell states, and their extensions to, for example, tripartite systems. The 'Group' of the title is the Braid Group in its various representations; while 'Tangle' refers to the property of entanglement which is present in both of these scenarios. The objective of this note is to explore the relation between Quantum Entanglement and Topological Links, and to show that the use of the language of entanglement in both cases is more than one of linguistic analogy.

  18. FAW Group Gorporation

    Institute of Scientific and Technical Information of China (English)

    Yan Feng

    2007-01-01

    @@ As the founder of China's automobile industry, FAW Group Corporation (FAW) has maintained a dominant position in the automotive industry since its founding in 1953 in terms of its total assets, Production capacity, domestic and international sales, market share, and brand recognition.

  19. Group theory in cryptography

    CERN Document Server

    Blackburn, Simon R; Mullan, Ciaran

    2009-01-01

    This paper is a guide for the pure mathematician who would like to know more about cryptography based on group theory. The paper gives a brief overview of the subject, and provides pointers to good textbooks, key research papers and recent survey papers in the area.

  20. Group theory in physics

    CERN Document Server

    Cornwell, J F

    1989-01-01

    Recent devopments, particularly in high-energy physics, have projected group theory and symmetry consideration into a central position in theoretical physics. These developments have taken physicists increasingly deeper into the fascinating world of pure mathematics. This work presents important mathematical developments of the last fifteen years in a form that is easy to comprehend and appreciate.

  1. Space Systems Academic Group

    OpenAIRE

    2006-01-01

    The Space Systems Academic Group (SSAG) along with eight academic departments is an integral part of the Graduate School of Engineering and Applied Sciences. As an interdisciplinary association of professors it provides direction and guidance for two curricula: Space Systems Engineering and Space Systems Operations.

  2. Teaching Badminton to Groups.

    Science.gov (United States)

    Nelson, Jonathan E.

    1980-01-01

    Numerous ideas for teaching badminton to large groups are presented. The focus is on drills and techniques for off the court instructional stations. Instead of having students waiting their turn to play, more students can participate actively as they rotate from one station to another. (JN)

  3. Unclonable Group Identification

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Dupont, Kasper; Pedersen, Michael Østergaard

    We introduce and motivate the concept of unclonable group identification, that provides maximal protection against sharing of identities while still protecting the anonymity of users. We prove that the notion can be realized from any one-way function and suggest a more efficient implementation...

  4. Group B Streptococcus

    Directory of Open Access Journals (Sweden)

    Albert H. Adriaanse

    1995-01-01

    Full Text Available Objective: Group B streptococcus (GBS, Streptococcus agalactiae is an important cause of neonatal sepsis. Prevention is possible by intrapartum screening for maternal GBS carriership and antimicrobial treatment of colonized women with risk factors during labor. The conflicting results of diagnostic performance are reported both for the newly developed rapid GBS antigen tests and Gram's stain.

  5. Cohomology of quantum groups

    CERN Document Server

    Frønsdal, Christian

    1995-01-01

    Lecture notes. Introduction to the cohomology of algebras, Lie algebras, Lie bialgebras and quantum groups. Contains a new derivation of the classification of classical r-matrices in terms of deformation cohomology, and a calculation of the esoteric forms of quantum gl(N) by deformation theory.

  6. End Group Modification

    DEFF Research Database (Denmark)

    Jahnsen, Rasmus O; Sandberg-Schaal, Anne; Frimodt-Møller, Niels; Nielsen, Hanne Mørck; Franzyk, Henrik

    , the most favorable hydrophobic activity-inducing moieties were found to be cyclohexylacetyl and pentafluorophenylacetyl groups, while the presence of a short PEG-like chain had no significant effect on activity. Introduction of cationic moieties conferred no effect or merely a moderate activity...

  7. Abandoning wells working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The primary objective of this working group is to identify major technical, regulatory, and environmental issues that are relevant to the abandonment of offshore wellbores. Once the issues have been identified, the working group also has the objective of making recommendations or providing potential solutions for consideration. Areas for process improvement will be identified and {open_quotes}best practices{close_quotes} will be discussed and compared to {open_quotes}minimum standards.{close_quotes} The working group will primarily focus on wellbore abandonment in the Gulf of Mexico. However, workshop participants are encouraged to discuss international issues which may be relevant to wellbore abandonment practices in the Gulf of Mexico. The Abandoning Wells Group has identified several major areas for discussion that have concerns related to both operators and service companies performing wellbore abandonments in the Gulf of Mexico. The following broad topics were selected for the agenda: (1) MMS minimum requirements and state regulations. (2) Co-existence of best practices, new technology, and P & A economics. (3) Liability and environmental issues relating to wellbore abandonment.

  8. Geodesic Renormalisation Group Flow

    OpenAIRE

    Dolan, Brian P

    1995-01-01

    It is shown that the renormalisation group flow in coupling constant space can be interpreted in terms of a dynamical equation for the couplings analogous to viscous fluid flow under the action of a potential. For free scalar field theory the flow is geodesic in two dimensions, while for $D \

  9. Teaching the renormalization group

    International Nuclear Information System (INIS)

    The renormalization group theory of continuous phase transitions is described with the use of a hands on model suitable for presentation as part of an undergraduate thermal physics course. It is an extension of the work of Maris and Kadanoff in that key concepts such as universality fixed points and critical surface are introduced

  10. With the Radiobiology Group

    CERN Multimedia

    1980-01-01

    The Radiobiology Group carries out experiments to study the effect of radiation on living cells. The photo shows the apparatus for growing broad beans which have been irradiated by 250 GeV protons. The roots are immersed in a tank of running water (CERN Weekly Bulletin 26 January 1981 and Annual Report 1980 p. 160). Karen Panman, Marilena Streit-Bianchi, Roger Paris.

  11. Cohomology of kleinian groups.

    Science.gov (United States)

    Kra, I

    1969-07-01

    Let [unk] be a (nonelementary) Kleinian group and q >/= 2 an integer. The group [unk] acts in a natural way on the vector space II(2q-2) of complex polynomials in one variable of degree group of [unk] with coefficients in II(2q-2). There are essentially two ways of constructing cohomology classes. One construction originated with Eichler and has recently been extended by Ahlfors. Another construction is due to Bers. We show that for finitely generated [unk], every cohomology class pepsilon H(1)([unk],II(2q-2)) can be written uniquely (if one chooses an invariant union of components of [unk]) as a sum of a Bers cohomology class and an Eichler cohomology class. Similar decompositions are obtained for the subgroups of parabolic cohomology classes introduced by Ahlfors. Some information on the structure of H(1)([unk],II(2q-2)) for infinitely generated groups [unk] is also obtained. PMID:16591774

  12. Anti- CC-Groups and Anti-PC-Groups

    Directory of Open Access Journals (Sweden)

    Francesco Russo

    2007-01-01

    subgroup H of G. An anti-PC group G is a group in which each nonfinitely generated subgroup K has the quotient group G/coreG(NG(K which is a polycyclic-by-finite group. Anti-CC groups and anti-PC groups are the subject of the present article.

  13. Nonequilibrium Renormalization Group

    International Nuclear Information System (INIS)

    Thermal equilibrium properties of many-body or field theories are known to be efficiently classified in terms of renormalization group fixed points. A particularly powerful concept is the notion of infrared fixed points, which are characterized by universality. These correspond to critical phenomena in thermal equilibrium, where a characteristic large correlation length leads to independence of long-distance properties from details of the underlying microscopic theory. In contrast, a classification of properties of theories far from thermal equilibrium in terms of renormalization group fixed points is much less developed. The notion of universality or critical phenomena far from equilibrium is to a large extent unexplored, in particular, in relativistic quantum field theories. Here the strong interest is mainly driven by theoretical and experimental advances in our understanding of early universe cosmology as well as relativistic collision experiments of heavy nuclei in the laboratory. In these lectures I will introduce the functional renormalization group for the effective average action out of equilibrium. While in equilibrium typically a Euclidean formulation is adequate, nonequilibrium properties require real-time descriptions. For quantum systems a generating functional for nonequilibrium correlation functions with given density matrix at initial time can be written down using the Schwinger-Keldysh closed time path contour. In principle, this can be used to construct a nonequilibrium functional renormalization group along similar lines as for Euclidean field theories in thermal equilibrium. However, important differences include the absence of time-translation invariance for general out-of-equilibrium situations. The nonequilibrium renormalization group takes on a particularly simple form at a fixed point, since it becomes independent of the initial density matrix. I will discuss some simple examples for which I derive a hierarchy of fixed point solutions

  14. Mindfulness for group facilitation

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Krohn, Simon

    2014-01-01

    In this paper, we argue that mindfulness techniques can be used for enhancing the outcome of group performance. The word mindfulness has different connotations in the academic literature. Broadly speaking there is ‘mindfulness without meditation’ or ‘Western’ mindfulness which involves active...... thinking and ‘Eastern’ mindfulness which refers to an open, accepting state of mind, as intended with Buddhist-inspired techniques such as meditation. In this paper, we are interested in the latter type of mindfulness and demonstrate how Eastern mindfulness techniques can be used as a tool for facilitation....... A brief introduction to the physiology and philosophy of Eastern mindfulness constitutes the basis for the arguments of the effect of mindfulness techniques. The use of mindfulness techniques for group facilitation is novel as it changes the focus from individuals’ mindfulness practice to that of...

  15. Working group 4: Terrestrial

    International Nuclear Information System (INIS)

    A working group at a Canada/USA symposium on climate change and the Arctic identified major concerns and issues related to terrestrial resources. The group examined the need for, and the means of, involving resource managers and users at local and territorial levels in the process of identifying and examining the impacts and consequences of climatic change. Climatic change will be important to the Arctic because of the magnitude of the change projected for northern latitudes; the apparent sensitivity of its terrestrial ecosystems, natural resources, and human support systems; and the dependence of the social, cultural, and economic welfare of Arctic communities, businesses, and industries on the health and quality of their environment. Impacts of climatic change on the physical, biological, and associated socio-economic environment are outlined. Gaps in knowledge needed to quantify these impacts are listed along with their relationships with resource management. Finally, potential actions for response and adaptation are presented

  16. Two Abelian group constructions

    International Nuclear Information System (INIS)

    Let A be an Abelian group and n an integer >1. Let D be a divisible hull of A. Define A0sup((D))=A,Asub(r)sup((D)) = set containing x is an element of D|nx=y, for some y is an element of Asub(r=1)sup((D)), r=1,2,3,..., and Asub([n])sup((D))=Usub(r=0)sup(infinity)Asub(r)sup((D)). Then each Asub(r)sup((D)) is a subgroup of D and Asub([n])sup((D)) is the smallest n-divisible subgroup of D which contains A. Define Asub((D))sup([n])=Asub([n])sup((D))/A. A number of theorems and propositions are proved for the groups Asub([n])sup((D)) and Asub((D))sup([n])

  17. Group Formation in Economics

    Science.gov (United States)

    Demange, Gabrielle; Wooders, Myrna

    2005-01-01

    Broad and diverse ranges of activities are conducted within and by organized groups of individuals, including political, economic and social activities. These activities have recently become a subject of intense interest in economics and game theory. Some of the topics investigated in this collection are models of networks of power and privilege, trade networks, co-authorship networks, buyer-seller networks with differentiated products, and networks of medical innovation and the adaptation of new information. Other topics are social norms on punctuality, clubs and the provision of club goods and public goods, research and development and collusive alliances among corporations, and international alliances and trading agreements. While relatively recent, the literature on game theoretic studies of group formation in economics is already vast. This volume provides an introduction to this important literature on game-theoretic treatments of situations with networks, clubs, and coalitions, including some applications.

  18. ST Quality Working Group

    CERN Document Server

    Akhtar, S

    2000-01-01

    When CERN engages contractors or outside enterprises for supply and service contracts, a Quality certification is requested. CERN itself has no global certification. Nor are quality assurance systems well understood by the majority of CERN staff. This has not precluded successful activity but it is felt that a structured approach would have some benefits: elimination of occasional accelerator perturbations, improved documentation, efficient use of existing resources, enhanced sharing of experience and knowledge, avoidance of improper handover periods when staff leave CERN. In some cases talented staff spend too much time doing remedial jobs when they are capable of achieving much more. The ST quality working group was formed to address these problems. The goal of this quality working group is to help ST division maintain and continuously improve the quality of its services and operations, and give confidence to ST staff and clients that the requirements for quality are being fulfilled, maintained and improved...

  19. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    Please note that owing the preparations for the Open Days, the FM Group will not able to handle specific requests for waste collection from 2nd to 6th of April, nor removal or PC transport requests between the 31 March and 11 April. We kindly ask you to plan the collection of all types of waste and any urgent transport of office furniture or PCs before 31 March. Waste collection requests must be made by contacting FM Support on 77777 or at the e-mail address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form (select "Removals" or "PC transport" from the drop-down menu). For any question concerning the sorting of waste, please consult the following web site: http://dechets-waste.web.cern.ch/dechets-waste/ Thank you for your understanding and collaboration. TS/FM Group

  20. The Ombudperson Initiative Group

    CERN Multimedia

    Laura Stewart

    Following many discussions that took place at some of the ATLAS Women's Network lunch gatherings, a few ATLAS women joined forces with similarly concerned CERN staff women to form a small group last Fall to discuss the need for a CERN-wide Ombudsperson. This has since evolved into the Ombudsperson Initiative Group (OIG) currently composed of the following members: Barbro Asman, Stockholm University; Pierre Charrue, CERN AB; Anna Cook, CERN IT; Catherine Delamare, CERN and IT Ombudsperson; Paula Eerola, Lund University; Pauline Gagnon, Indiana University; Eugenia Hatziangeli, CERN AB; Doreen Klem, CERN IT; Bertrand Nicquevert, CERN TS and Laura Stewart, CERN AT. On June 12, members of the OIG met with representatives of Human Resources (HR) and the Equal Opportunity Advisory Panel (EOAP) to discuss the proposal drafted by the OIG. The meeting was very positive. Everybody agreed that the current procedures at CERN applicable in the event of conflict required a thorough review, and that a professionnally trai...

  1. The Areva Group

    International Nuclear Information System (INIS)

    This document provides information on the Areva Group, a world nuclear industry leader, offering solutions for nuclear power generation, electricity transmission and distribution and interconnect systems to the telecommunications, computer and automotive markets. It presents successively the front end division including the group business lines involved in producing nuclear fuel for electric power generation (uranium mining, concentration, conversion and enrichment and nuclear fuel fabrication); the reactors and services division which designs and builds PWR, BWR and research reactors; the back end division which encompasses the management of the fuel that has been used in nuclear power plants; the transmission and distribution division which provides products, systems and services to the medium and high voltage energy markets; the connectors division which designs and manufactures electrical, electronic and optical connectors, flexible micro circuitry and interconnection systems. Areva is implemented in Europe, north and south america, africa and asia-pacific. (A.L.B.)

  2. Working group 2: Freshwater

    International Nuclear Information System (INIS)

    A working group at a Canada-USA symposium on climate change in the Arctic addressed freshwater issues from the perspective of water resource planning and management. Two issues were selected for discussion and identification of relationships with resource management: hydroelectric production and waste disposal. Gaps in knowledge about climate and water resources were identified along with potential actions for response and adaptation to climate change. Recommendations are offered to improve knowledge of Arctic climate and hydrology

  3. Combinatorial group theory

    CERN Document Server

    Lyndon, Roger C

    2001-01-01

    From the reviews: "This book (...) defines the boundaries of the subject now called combinatorial group theory. (...)it is a considerable achievement to have concentrated a survey of the subject into 339 pages. This includes a substantial and useful bibliography; (over 1100 ÄitemsÜ). ...the book is a valuable and welcome addition to the literature, containing many results not previously available in a book. It will undoubtedly become a standard reference." Mathematical Reviews, AMS, 1979.

  4. Equity valuation : Eurocash Group

    OpenAIRE

    Branco, Ana Isabel Antunes de Azevedo

    2015-01-01

    Equity valuation is an extremely complex and subjective process, it depends not only on the theoretical models but also on the analysis and assumptions used by the analyst. This thesis focuses on the valuation of Eurocash Group, a leading wholesale distributor of fast moving consumer goods (FMCG) in Poland. In order to present stronger conclusions we decided to use two different models: the discounted cash-flow (DCF) model and the multiples method as a complement. The combination of both l...

  5. KKG Group Paraffin Removal

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Ralph

    2001-12-01

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed a test of a paraffin removal system developed by the KKG Group utilizing the technology of two Russian scientists, Gennady Katzyn and Boris Koggi. The system consisting of chemical ''sticks'' that generate heat in-situ to melt the paraffin deposits in oilfield tubing. The melted paraffin is then brought to the surface utilizing the naturally flowing energy of the well.

  6. Holonomy groups and spacetimes

    OpenAIRE

    Hall, G. S.; Lonie, D. P.

    2003-01-01

    A study is made of the possible holonomy group types of a space-time for which the energy-momentum tensor corresponds to a null or non-null electromagnetic field, a perfect fluid or a massive scalar field. The case of an Einstein space is also included. The techniques developed are also applied to vacuum and conformally flat space-times and contrasted with already known results in these two cases. Examples are given.

  7. Holonomy groups and spacetimes

    CERN Document Server

    Hall, G S

    2000-01-01

    A study is made of the possible holonomy group types of a space-time for which the energy-momentum tensor corresponds to a null or non-null electromagnetic field, a perfect fluid or a massive scalar field. The case of an Einstein space is also included. The techniques developed are also applied to vacuum and conformally flat space-times and contrasted with already known results in these two cases. Examples are given.

  8. Hadron hadron collider group

    International Nuclear Information System (INIS)

    The objective of this group was to make a rough assessment of the characteristics of a hadron-hadron collider which could make it possible to study the 1 TeV mass scale. Since there is very little theoretical guidance for the type of experimental measurements which could illuminate this mass scale, we chose to extend the types of experiments which have been done at the ISR, and which are in progress at the SPS collider to these higher energies

  9. Heavy flavors study group

    International Nuclear Information System (INIS)

    The heavy flavor study group concentrated on three issues. First the investigation of an energy transverse trigger to be used to select out charm and beauty events. Second, in a dedicated high sensitivity two-body B experiment is it possible to ''tag'' the beauty particle. Third, the design of a photoproduction experiment that could accumulate 108 charm particles in a single Fermilab running period

  10. Ocenenie Volkswagen Group

    OpenAIRE

    Šusták, Tomáš

    2010-01-01

    Objective of the thesis is determination of Volkswagen Group's equity intrinsic value. Basic starting point of the analysis is seggregation of consolidated financial statements into financial and production division, which are valuated separately. The production division is valuated using both enterprise discounted cashflow and discounted economic profit analysis. Equity cashflow valuation is used to derive value of the financial division. Results of valuation implied by income approach are t...

  11. Multibunch working group

    International Nuclear Information System (INIS)

    The goal of this working group was to foment discussions about the use and limitations of multi-bunch, representatives from most operating or in-project synchrotron radiation sources (ALS, SPEAR, BESSY-2, SPRING-8, ANKA, DELTA, PEP-2, DIAMOND, ESRF...) have presented their experience. The discussions have been led around 3 topics: 1) resistive wall instabilities and ion instabilities, 2) higher harmonic cavities, and 3) multibunch feedback systems

  12. Group process and group phenomena on the Internet.

    Science.gov (United States)

    Weinberg, H

    2001-07-01

    This article identifies group processes and group phenomena in discussion lists on the Internet and examines the differences and similarities with the processes in small and large groups. Group dynamics and phenomena, such as boundaries, cohesion, transference, scapegoating, and the leader's role are addressed. Large group features, such as alienation, vulnerability, and the vast amount of issues discussed in parallel are described. There are similarities between the discussion list and small groups on issues of cohesion and group norms, and in the psychological mechanisms of transference and scapegoating. There are differences regarding the contract, boundaries, leaving the group, and extra-group socialization. Although many of the phenomena described resemble a large group, a discussion list on the Internet maintains the illusion of being a small group and frequently acts like one. While a virtual therapy group would be somewhat different from a real group, it could nonetheless be useful. PMID:11447785

  13. Outer automorphism groups of certain 1-relator groups

    Institute of Scientific and Technical Information of China (English)

    KIM; Goansu

    2010-01-01

    Grossman first showed that outer automorphism groups of 1-relator groups given by orientable surface groups are residually finite,whence mapping class groups of orientable surfaces are residually finite.Allenby,Kim and Tang showed that outer automorphism groups of cyclically pinched 1-relator groups are residually finite,whence mapping class groups of orientable and non-orientable surfaces are residually finite.In this paper we show that outer automorphism groups of certain conjugacy separable 1-relator groups are residually finite.

  14. Countable groups are mapping class groups of hyperbolic 3-manifolds

    OpenAIRE

    Frigerio, Roberto; Martelli, Bruno

    2005-01-01

    We prove that for every countable group G there exists a hyperbolic 3-manifold M such that the isometry group of M, the mapping class group of M, and the outer automorphism group of the fundamental group of M are isomorphic to G.

  15. Quality of Group Member Agendas and Group Session Climate.

    Science.gov (United States)

    Kivlighan, Dennis M., Jr.; Jauquet, Carol A.

    1990-01-01

    Examined relationship between group members' (N=36) approach to group sessions and group session climate and relationship between length of time in group and agenda quality. Found average ratings of interpersonal and here-and-now dimensions of agendas were significantly related to average perception of group climate as more engaged and less…

  16. Technology working group

    International Nuclear Information System (INIS)

    The workshop of 26-27 june 2000, on nuclear power Plant LIfe Management (PLIM), also included working groups in which major issues facing PLIM activities for nuclear power plants were identified and discussed. The first group was on Technology. Utilities should consider required provisions capacity by properly maintaining and preserving the existing power plants to the extent practicable and taking into account growing demand, limits of energy conservation, and difficulties in finding new power plant sites. Generally, the extension of the life of nuclear power plant (e.g. from 40 years to 60 years) is an attractive option for utilities, as the marginal cost of most existing nuclear power plants is lower than that of almost all other power sources. It is also an attractive option for environmental protection. Consequently, PLIM has become an important issue in the context of the regulatory reform of the electricity markets. Therefore, the three main objectives of the Technology working group are: 1) Documenting how the safety of nuclear power plants being operated for the long-term has been confirmed, and suggesting ways of sharing this information. 2) Addressing development of advanced maintenance technologies necessary over the plant lifetime, and clarifying their technical challenges. 3) Suggesting potential areas of research and development that might, be necessary. Some potential examples of such research include: - improving the effectiveness of maintenance methods to assure detection of incipient faults; - providing cost effective preventive maintenance programmes; - furnishing systematic, cost-effective refurbishment programmes framed to be consistent with efforts to extend the time between re-fuelling; - developing a methodology that moves routine maintenance on-line without compromising safety. (author)

  17. Unilever Group : equity valuation

    OpenAIRE

    Pires, Susana Sofia Castelo

    2014-01-01

    The following dissertation has the purpose to value the Unilever Group, but more specifically Unilever N.V. being publicly traded in the Amsterdam Exchange Index. Unilever is seen as a global player and one of most successful and competitive fast-moving consumer goods companies. In order to valuate Unilever’s equity, a Discounted Cash Flow (DCF) approach is first carried out, since it is believed to be the most reliable methodology. The value estimated was €36.39, advising one to buy its s...

  18. Statistical Group Comparison

    CERN Document Server

    Liao, Tim Futing

    2011-01-01

    An incomparably useful examination of statistical methods for comparisonThe nature of doing science, be it natural or social, inevitably calls for comparison. Statistical methods are at the heart of such comparison, for they not only help us gain understanding of the world around us but often define how our research is to be carried out. The need to compare between groups is best exemplified by experiments, which have clearly defined statistical methods. However, true experiments are not always possible. What complicates the matter more is a great deal of diversity in factors that are not inde

  19. Bevalac computer support group

    International Nuclear Information System (INIS)

    During the past year, a group was created and placed under the leadership of Charles McParland. This is an expansion of previous Bevalac software efforts and has responsibilities in three major hardware and software areas. The first area is the support of the existing data acquisition/analysis VAX 11/780s at the Bevalac. The second area is the continued support of present data acquisition programs. The third principal area of effort is the development of new data acquisition systems to meet the increasing needs of the Bevalac experimental program

  20. Theory and modeling group

    Science.gov (United States)

    Holman, Gordon D.

    The primary purpose of the Theory and Modeling Group meeting was to identify scientists engaged or interested in theoretical work pertinent to the Max '91 program, and to encourage theorists to pursue modeling which is directly relevant to data which can be expected to result from the program. A list of participants and their institutions is presented. Two solar flare paradigms were discussed during the meeting -- the importance of magnetic reconnection in flares and the applicability of numerical simulation results to solar flare studies.

  1. Arithmetic of Quaternion Groups

    OpenAIRE

    Jahangiri, Majid

    2009-01-01

    Let $p$ be a prime and $a$ a quadratic non-residue $\\bmod p$. Then the set of integral solutions of the diophantine equation $x_0^2 - ax_1^2 -px_2^2 + apx_3^2=1$ form a cocompact discrete subgroup $\\Gamma_{p,a}\\subset SL(2,\\mathbb{R})$ and is commensurable with the group of units of an order in a quaternion algebra over $\\mathbb{Q}$. The problem addressed in this paper is an estimate for the traces of a set of generators for $\\Gamma_{p,a}$. Empirical results summarized in several tables show ...

  2. GroupFinder

    DEFF Research Database (Denmark)

    Bøgh, Kenneth Sejdenfaden; Skovsgaard, Anders; Jensen, Christian S.

    2013-01-01

    The notion of point-of-interest (PoI) has existed since paper road maps began to include markings of useful places such as gas stations, hotels, and tourist attractions. With the introduction of geopositioned mobile devices such as smartphones and mapping services such as Google Maps, the retrieval...... existing proposals retrieve results at single-PoI granularity. We assume that a mobile device user issues queries consisting of keywords and an automatically supplied geo-position, and we target the common case where the user wishes to find nearby groups of PoIs that are relevant to the keywords. Such...

  3. Social group utility maximization

    CERN Document Server

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan

    2014-01-01

    This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

  4. The technical review group

    International Nuclear Information System (INIS)

    This paper describes the formation of a technical review group (TRG) as an early application of the quality assurance program for high-level waste processing. The objectives and functions for a TRG are summarized. Organizational structure is presented. Interfaces for the TRG are described by a flow diagram following the review process from the originator's document submittal to the final approval. Interfacing organizations and their responsibilities during the review are shown. Experience to date with TRG activities are described and QA interaction is discussed

  5. Grouping Synonyms by Definitions

    OpenAIRE

    Falk, Ingrid; Gardent, Claire; Jacquey, Evelyne; Venant, Fabienne

    2009-01-01

    We present a method for grouping the synonyms of a lemma according to its dictionary senses. The senses are defined by a large machine readable dictionary for French, the TLFi (Tr\\'esor de la langue fran\\c{c}aise informatis\\'e) and the synonyms are given by 5 synonym dictionaries (also for French). To evaluate the proposed method, we manually constructed a gold standard where for each (word, definition) pair and given the set of synonyms defined for that word by the 5 synonym dictionaries, 4 ...

  6. Quantum Group $\\sigma$ Models

    CERN Document Server

    Frishman, Yitzhak; Zakrzewski, W J

    1993-01-01

    Field-theoretic models for fields taking values in quantum groups are investigated. First we consider $SU_q(2)$ $\\sigma$ model ($q$ real) expressed in terms of basic notions of noncommutative differential geometry. We discuss the case in which the $\\sigma$ models fields are represented as products of conventional $\\sigma$ fields and of the coordinate-independent algebra. An explicit example is provided by the $U_q(2)$ $\\sigma$ model with $q\\sp{N}=1$, in which case quantum matrices $U_q(2)$ are realised as $2N\\times 2N$ unitary matrices. Open problems are pointed out.

  7. Quantum Group $\\sigma$ Models

    OpenAIRE

    Frishman, Y.; Lukierski, J.; Zakrzewski, W. J.

    1992-01-01

    Field-theoretic models for fields taking values in quantum groups are investigated. First we consider $SU_q(2)$ $\\sigma$ model ($q$ real) expressed in terms of basic notions of noncommutative differential geometry. We discuss the case in which the $\\sigma$ models fields are represented as products of conventional $\\sigma$ fields and of the coordinate-independent algebra. An explicit example is provided by the $U_q(2)$ $\\sigma$ model with $q\\sp{N}=1$, in which case quantum matrices $U_q(2)$ ar...

  8. Representation Theory of Algebraic Groups and Quantum Groups

    CERN Document Server

    Gyoja, A; Shinoda, K-I; Shoji, T; Tanisaki, Toshiyuki

    2010-01-01

    Invited articles by top notch expertsFocus is on topics in representation theory of algebraic groups and quantum groupsOf interest to graduate students and researchers in representation theory, group theory, algebraic geometry, quantum theory and math physics

  9. Quantum group gauge fields

    International Nuclear Information System (INIS)

    This paper reports on a kind of solution in the effective theory of superstring. It was shown that extra time-like coordinates can solve the cosmological constant problem. To avoid the appearance of massless ghost we had to put some topological restrictions on the internal space K. One of this restriction is that K has no Killings vectors at all. Equation of motion got us that K has negative curvature. The simplest example of a manifold with negative curvature is an hyperboloid which is non-compact. In the σ-model approach this means that we have to deal with non-compact σ-models. Namely such type of σ-models is a subject of recent investigations in the context of the 2-dim gravity coupled with c=1 matter. However one can assume that K is a compact hyperbolic manifold. Such manifolds have rather complicated topology. In the usually adopted field theories fields take values in the simplest manifolds (line, plane, sphere, group, coset space, etc.). However adopted the possibility for signature to be the dynamical variable we have to deal with fields taken values in manifolds with complicate topology. One can go one step forward and try to consider field theories in which fields are more complicate objects, for example, are elements of quantum plane or quantum group

  10. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  11. Biology task group

    International Nuclear Information System (INIS)

    The accomplishments of the task group studies over the past year are reviewed. The purposes of biological investigations, in the context of subseabed disposal, are: an evaluation of the dose to man; an estimation of effects on the ecosystem; and an estimation of the influence of organisms on and as barriers to radionuclide migration. To accomplish these ends, the task group adopted the following research goals: (1) acquire more data on biological accumulation of specific radionuclides, such as those of Tc, Np, Ra, and Sr; (2) acquire more data on transfer coefficients from sediment to organism; (3) Calculate mass transfer rates, construct simple models using them, and estimate collective dose commitment; (4) Identify specific pathways or transfer routes, determine the rates of transfer, and make dose limit calculations with simple models; (5) Calculate dose rates to and estimate irradiation effects on the biota as a result of waste emplacement, by reference to background irradiation calculations. (6) Examine the effect of the biota on altering sediment/water radionuclide exchange; (7) Consider the biological data required to address different accident scenarios; (8) Continue to provide the basic biological information for all of the above, and ensure that the system analysis model is based on the most realistic and up-to-date concepts of marine biologists; and (9) Ensure by way of free exchange of information that the data used in any model are the best currently available

  12. Business working group

    International Nuclear Information System (INIS)

    The workshop of 26-27 june 2000, on nuclear power Plant LIfe Management (PLIM), also included working groups in which major issues facing PLIM activities for nuclear power plants were identified and discussed. The third group was on Business. The discussion concerned the following points: There are concerns about retaining experienced/trained personnel, and maintaining a good working relationship among them, as well as about the closure of research facilities, the reduction in staff numbers under increasing economic pressure and the lack of new nuclear power plant constructions. The marginal cost of producing electricity is lower for most existing nuclear power plants than for almost all other energy sources. Refurbishment costs are usually relatively small compared with new investments. The ongoing regulatory reform of the electricity market will bring increasing competition. Although PLIM has been carried out in many countries with favourable results, there are still uncertainties which affect business decisions regarding financial and market risks in PLIM activities. Recommendations were made. (author)

  13. Group Life Insurance

    CERN Multimedia

    2013-01-01

    The CERN Administration would like to remind you that staff members and fellows have the possibility to take out a life insurance contract on favourable terms through a Group Life Insurance.   This insurance is provided by the company Helvetia and is available to you on a voluntary basis. The premium, which varies depending on the age and gender of the person insured, is calculated on the basis of the amount of the death benefit chosen by the staff member/fellow and can be purchased in slices of 10,000 CHF.    The contract normally ends at the retirement age (65/67 years) or when the staff member/fellow leaves the Organization. The premium is deducted monthly from the payroll.   Upon retirement, the staff member can opt to maintain his membership under certain conditions.   More information about Group Life Insurance can be found at: Regulations (in French) Table of premiums The Pension Fund Benefit Service &...

  14. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    In order to prepare the organization of the Open Days, please note that FM Group will not able to take into account either specific requests for waste collection from 2nd to 6th of April, either removal or PC transport requests between the 31st and the 11th of March. We kindly ask you to plan the collection of any type of waste and the urgent transport of office furniture or PC before the 31st of March. Waste collection requests shall be formulated contacting FM Support at 77777 or at the email address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form selecting the "Removals" or the "PC transport" category from the drop-down menu. For any question concerning the waste sorting, please consult the following web address: http://dechets-waste.web.cern.ch/dechets-waste/. Thank you for your understanding and collaboration. TS/FM Group

  15. On the Brauer group

    International Nuclear Information System (INIS)

    For an arithmetic model X of a Fermat surface or a hyperkahler variety with Betti number b2(V otimes k-bar)>3 over a purely imaginary number field k, we prove the finiteness of the l-components of Br'(X) for all primes l>>0. This yields a variant of a conjecture of M. Artin. If V is a smooth projective irregular surface over a number field k and V(k)≠ nothing, then the l-primary component of Br(V)/Br(k) is an infinite group for every prime l. Let A1→M1 be the universal family of elliptic curves with a Jacobian structure of level N>=3 over a number field k supset of Q(e2πi/N). Assume that M1(k) ≠ nothing. If V is a smooth projective compactification of the surface A1, then the l-primary component of Br(V)/Br(M-bar1) is a finite group for each sufficiently large prime l

  16. Social group and mobbing

    Directory of Open Access Journals (Sweden)

    Baltezarević Vesna

    2009-01-01

    Full Text Available Our reality, having been subject to the numerous social crises during the last decades of the 20th century, is characterized by frequent incidences of powerlessness and alienation. The man is more frequently a subject to loneliness and overcomes the feeling of worthlessness, no matter whether he considers himself an individual or a part of a whole larger social. Such an environment leads to development of aggression in all fields of ones life. This paper has as an objective the pointing out of the mental harassment that is manifested in the working environment. There is a prevalence of mobbing cases, as a mode of pathological communication. The result of this is that a person, subjected to this kind of abuse, is soon faced with social isolation. This research also aspires to initiate the need for social groups self-organization of which victims are part of. The reaction modality of a social group directly conditions the outcome of the deliberate social drama, one is subjected to it as a result of mobbing.

  17. On Generalized PST-groups

    Institute of Scientific and Technical Information of China (English)

    WANG JUN-XIN; Du Xian-kun

    2011-01-01

    A finite group G is called a generalized PST-group if every subgroup contained in F(G) permutes all Sylow subgroups of G,where F(G) is the Fitting subgroup of G.The class of generalized PST-groups is not subgroup and quotient group closed,and it properly contains the class of PST-groups.In this paper,the structure of generalized PST-groups is first investigated.Then,with its help,groups whose every subgroup (or every quotient group) is a generalized PST-group are determined,and it is shown that such groups are precisely PST-groups.As applications,T-groups and PT-groups are characterized.

  18. Braided C*-quantum groups

    OpenAIRE

    Roy, Sutanu

    2016-01-01

    We propose a general theory of braided quantum groups in the C*-algebraic framework. More precisely, we construct braided quantum groups using manageable braided multiplicative unitaries over a regular C*-quantum group. We show that braided C*-quantum groups are equivalent to C*-quantum groups with projection.

  19. CORRELATION BETWEEN GROUP LOCAL DENSITY AND GROUP LUMINOSITY

    International Nuclear Information System (INIS)

    In this study, we investigate the correlation between group local number density and total luminosity of groups. In four volume-limited group catalogs, we can conclude that groups with high luminosity exist preferentially in high-density regions, while groups with low luminosity are located preferentially in low-density regions, and that in a volume-limited group sample with absolute magnitude limit Mr = –18, the correlation between group local number density and total luminosity of groups is the weakest. These results basically are consistent with the environmental dependence of galaxy luminosity.

  20. Group and ring theoretic properties of polycyclic groups

    CERN Document Server

    Wehrfritz, BAF

    2009-01-01

    Polycyclic groups are built from cyclic groups in a specific way. They arise in many contexts within group theory itself but also more generally in algebra, for example in the theory of Noetherian rings. The first half of this book develops the standard group theoretic techniques for studying polycyclic groups and the basic properties of these groups. The second half then focuses specifically on the ring theoretic properties of polycyclic groups and their applications, often to purely group theoretic situations. The book is intended to be a study manual for graduate students and researchers co

  1. Gutzwiller renormalization group

    Science.gov (United States)

    Lanatà, Nicola; Yao, Yong-Xin; Deng, Xiaoyu; Wang, Cai-Zhuang; Ho, Kai-Ming; Kotliar, Gabriel

    2016-01-01

    We develop a variational scheme called the "Gutzwiller renormalization group" (GRG), which enables us to calculate the ground state of Anderson impurity models (AIM) with arbitrary numerical precision. Our method exploits the low-entanglement property of the ground state of local Hamiltonians in combination with the framework of the Gutzwiller wave function and indicates that the ground state of the AIM has a very simple structure, which can be represented very accurately in terms of a surprisingly small number of variational parameters. We perform benchmark calculations of the single-band AIM that validate our theory and suggest that the GRG might enable us to study complex systems beyond the reach of the other methods presently available and pave the way to interesting generalizations, e.g., to nonequilibrium transport in nanostructures.

  2. Group life insurance

    CERN Multimedia

    2013-01-01

    The CERN Administration wishes to inform staff members and fellows having taken out optional life insurance under the group contract signed by CERN that the following changes to the rules and regulations entered into force on 1 January 2013:   The maximum age for an active member has been extended from 65 to 67 years. The beneficiary clause now allows insured persons to designate one or more persons of their choice to be their beneficiary(-ies), either at the time of taking out the insurance or at a later date, in which case the membership/modification form must be updated accordingly. Beneficiaries must be clearly identified (name, first name, date of birth, address).   The membership/modification form is available on the FP website: http://fp.web.cern.ch/helvetia-life-insurance For further information, please contact: Valentina Clavel (Tel. 73904) Peggy Pithioud (Tel. 72736)

  3. Doing focus group research

    DEFF Research Database (Denmark)

    Lindegaard, Laura Bang

    2014-01-01

    interview data can be of some use if the distinction between natural and contrived data is given up and replaced with a distinction between interview data as topic or as resource. In greater detail, such scholars argue that interview data are perfectly adequate if the researcher wants to study the topic of......Scholars of ethnomethodologically informed discourse studies are often sceptical of the use of interview data such as focus group data. Some scholars quite simply reject interview data with reference to a general preference for so-called naturally occurring data. Other scholars acknowledge that...... interview interaction, but inadequate as data for studying phenomena that go beyond the phenomenon of interview interaction. Neither of these more and less sceptical positions are, on the face of it, surprising due to the ethnomethodological commitment to study social order as accomplished in situ, not as...

  4. Working Group Report: Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Artuso, M.; et al.,

    2013-10-18

    Sensors play a key role in detecting both charged particles and photons for all three frontiers in Particle Physics. The signals from an individual sensor that can be used include ionization deposited, phonons created, or light emitted from excitations of the material. The individual sensors are then typically arrayed for detection of individual particles or groups of particles. Mounting of new, ever higher performance experiments, often depend on advances in sensors in a range of performance characteristics. These performance metrics can include position resolution for passing particles, time resolution on particles impacting the sensor, and overall rate capabilities. In addition the feasible detector area and cost frequently provides a limit to what can be built and therefore is often another area where improvements are important. Finally, radiation tolerance is becoming a requirement in a broad array of devices. We present a status report on a broad category of sensors, including challenges for the future and work in progress to solve those challenges.

  5. Graphs, groups and surfaces

    CERN Document Server

    White, AT

    1985-01-01

    The field of topological graph theory has expanded greatly in the ten years since the first edition of this book appeared. The original nine chapters of this classic work have therefore been revised and updated. Six new chapters have been added, dealing with: voltage graphs, non-orientable imbeddings, block designs associated with graph imbeddings, hypergraph imbeddings, map automorphism groups and change ringing.Thirty-two new problems have been added to this new edition, so that there are now 181 in all; 22 of these have been designated as ``difficult'''' and 9 as ``unsolved''''. Three of the four unsolved problems from the first edition have been solved in the ten years between editions; they are now marked as ``difficult''''.

  6. Introduction to complex reflection groups and their braid groups

    CERN Document Server

    Broué, Michel

    2010-01-01

    Weyl groups are particular cases of complex reflection groups, i.e. finite subgroups of GLr(C) generated by (pseudo)reflections. These are groups whose polynomial ring of invariants is a polynomial algebra. It has recently been discovered that complex reflection groups play a key role in the theory of finite reductive groups, giving rise as they do to braid groups and generalized Hecke algebras which govern the representation theory of finite reductive groups. It is now also broadly agreed upon that many of the known properties of Weyl groups can be generalized to complex reflection groups. The purpose of this work is to present a fairly extensive treatment of many basic properties of complex reflection groups (characterization, Steinberg theorem, Gutkin-Opdam matrices, Solomon theorem and applications, etc.) including the basic findings of Springer theory on eigenspaces. In doing so, we also introduce basic definitions and properties of the associated braid groups, as well as a quick introduction to Bessis' ...

  7. The vls antigenic variation systems of Lyme disease Borrelia: eluding host immunity through both random, segmental gene conversion and framework heterogeneity

    OpenAIRE

    Norris, Steven J

    2014-01-01

    Spirochetes that cause Lyme borreliosis (also called Lyme disease) possess the vls locus, encoding an elaborate antigenic variation system. This locus contains the expression site vlsE as well as a contiguous array of vls silent cassettes, which contain variations of the central cassette region of vlsE. The locus is present on one of the many linear plasmids in the organism, e.g. plasmid lp28-1 in the strain B. burgdorferi B31. Changes in the sequence of vlsE occur continuously during mammali...

  8. Lyme disease: review

    OpenAIRE

    Biesiada, Grażyna; Czepiel, Jacek; Leśniak, Maciej R.; Garlicki, Aleksander; Mach, Tomasz

    2012-01-01

    Lyme disease is a multi-organ animal-borne disease, caused by spirochetes of Borrelia burgdorferi (Bb), which typically affect the skin, nervous system, musculoskeletal system and heart. A history of confirmed exposure to tick bites, typical signs and symptoms of Lyme borreliosis and positive tests for anti-Bb antibodies, are the basis of a diagnosis. A two-step diagnosis is necessary: the first step is based on a high sensitivity ELISA test with positive results confirmed by a more specific ...

  9. Harmonic Analysis and Group Representation

    CERN Document Server

    Figa-Talamanca, Alessandro

    2011-01-01

    This title includes: Lectures - A. Auslander, R. Tolimeri - Nilpotent groups and abelian varieties, M Cowling - Unitary and uniformly bounded representations of some simple Lie groups, M. Duflo - Construction de representations unitaires d'un groupe de Lie, R. Howe - On a notion of rank for unitary representations of the classical groups, V.S. Varadarajan - Eigenfunction expansions of semisimple Lie groups, and R. Zimmer - Ergodic theory, group representations and rigidity; and, Seminars - A. Koranyi - Some applications of Gelfand pairs in classical analysis.

  10. Working Group Versus Team Work

    OpenAIRE

    Valentina-Vasilica Zaharia; Mirela-Mihaela Dogaru; Dan-Marin Boaja

    2014-01-01

    The cell organization is represented by the working group and not the individual, groups that are a major feature of life organization. Quality circles were designed as tools for building team spirit in Japanese companies as a tool to enhance group cohesion and the training of employees. The essential characteristic of human behavior and organizational performance is given by the working group and the influence on group members, so members of the group leader should use in order to achieve a ...

  11. Cultural skepticism and 'group representation'

    OpenAIRE

    Phillips, Anne

    2011-01-01

    Arguments for group representation have commonly faced three objections: (1) that representing people via their membership of a group promotes sectionalism, parochialism, and the pursuit of vested interests; (2) that it raises impossible questions about which groups qualify for group representation; (3) that it falsely presumes the existence of a group with sufficiently shared interests, perspectives, values, or concerns for some of those group members fairly to represent the others. I have s...

  12. Group Leader Development: Effects of Personal Growth and Psychoeducational Groups

    Science.gov (United States)

    Ohrt, Jonathan H.; Robinson, E. H., III; Hagedorn, W. Bryce

    2013-01-01

    The purpose of this quasi-experimental study was to compare the effects of personal growth groups and psychoeducational groups on counselor education students' (n = 74) empathy and group leader self-efficacy. Additionally, we compared the degree to which participants in each group valued: (a) cohesion, (b) catharsis, and (c) insight. There were no…

  13. Group Development and Situational Leadership: A Model for Managing Groups.

    Science.gov (United States)

    Carew, Donald K.; And Others

    1986-01-01

    An integration of the concepts of situational leadership with what is known about group development and functioning of work groups is discussed as a tool in helping managers, trainers, and group members understand group development and determine the appropriate leader behaviors to use in various situations to build unified, cohesive, and…

  14. On Sufism, Sufi Group Study and Group Leadership.

    Science.gov (United States)

    Einhorn, Jay

    1979-01-01

    Sufism is an ancient tradition of experiential human development. Sufi human development specialists utilize the group setting as a major study format. Comparison with group counseling might broaden perspectives on the possibilities and pitfalls of group process, and pinpoint several important issues relevant to group leadership. (Author)

  15. Post-Disaster Social Justice Group Work and Group Supervision

    Science.gov (United States)

    Bemak, Fred; Chung, Rita Chi-Ying

    2011-01-01

    This article discusses post-disaster group counseling and group supervision using a social justice orientation for working with post-disaster survivors from underserved populations. The Disaster Cross-Cultural Counseling model is a culturally responsive group counseling model that infuses social justice into post-disaster group counseling and…

  16. Automorphism Groups of Finite p-Groups: Structure and Applications

    CERN Document Server

    Helleloid, Geir T

    2007-01-01

    This thesis has three goals related to the automorphism groups of finite $p$-groups. The primary goal is to provide a complete proof of a theorem showing that, in some asymptotic sense, the automorphism group of almost every finite $p$-group is itself a $p$-group. We originally proved this theorem in a paper with Martin; the presentation of the proof here contains omitted proof details and revised exposition. We also give a survey of the extant results on automorphism groups of finite $p$-groups, focusing on the order of the automorphism groups and on known examples. Finally, we explore a connection between automorphisms of finite $p$-groups and Markov chains. Specifically, we define a family of Markov chains on an elementary abelian $p$-group and bound the convergence rate of some of those chains.

  17. Group Milieu in systemic and psychodynamic group therapy

    DEFF Research Database (Denmark)

    Lau, Marianne Engelbrecht

    subscales: Cohesion (p< 0.05), Leader support (p=0.001), Expressiveness (p< 0.001), Task Orientation (p=0.01) and Order and Organization (p< 0.001). Conclusions: Substantial differences in the group milieu were seen. The systemic group turned out to be evaluated as the most structured therapy and also to be...... randomized study of systemic versus psychodynamic group therapy, that the short-term outcome for patients who received systemic group psychotherapy was significantly better than the outcome for patients who received psychodynamic group psychotherapy. The current study assessed the group milieu in both groups....... Methods: This randomized prospective study included 106 women: 52 assigned to psychodynamic group psychotherapy and 54 assigned to systemic group psychotherapy. The Group Environment Scale (GES) was filled in the mid phase of therapy and analysed in three dimensions and 10 subscales. Results: The systemic...

  18. Cryopreservation of an avian spirochete strain in liquid nitrogen

    Directory of Open Access Journals (Sweden)

    Labruna M.B.

    1999-01-01

    Full Text Available Soros de aves experimentalmente infectadas, contendo espiroquetas viáveis, foram submetidos a dois procedimentos antes da criopreservação: glicerol na diluição de 1/2 (v/v, designado como soro com glicerol a 50% (GS, e dimetilsulfóxido na proporção de 1/10 (v/v, designado como soro com DMSO a 10% (DS. Após 15 meses de estocagem em nitrogênio líquido, amostras dos tratamentos GS e DS foram descongeladas e suas infectividades foram testadas em frangos susceptíveis. Apesar de ambos os procedimentos terem mantidos a infectividade da bactéria, DMSO a 10% no soro de frango apresentou-se mais satisfatório como criopreservante.

  19. Absence of Lyme disease spirochetes in larval ixodes ricinus ticks

    Czech Academy of Sciences Publication Activity Database

    Richter, D.; Debski, A.; Hubálek, Zdeněk; Matuschka, F.-R.

    2012-01-01

    Roč. 12, č. 1 (2012), s. 21-27. ISSN 1530-3667 Grant ostatní: 6th Framework Programme(XE) GOCE-2003-010284 EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : blood meal * Borrelia * Ixodes * Lyme disease * Vertical transmission Subject RIV: EE - Microbiology, Virology Impact factor: 2.277, year: 2012

  20. Detection of spirochetes in, and isolation from, culicine mosquitoes

    Czech Academy of Sciences Publication Activity Database

    Sanogo, Yibayiri Osée; Halouzka, Jiří; Hubálek, Zdeněk; Němec, M.

    2000-01-01

    Roč. 47, č. 1 (2000), s. 79-80. ISSN 0015-5683 R&D Projects: GA AV ČR IAA6087601 Subject RIV: EE - Microbiology, Virology Impact factor: 0.844, year: 2000 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=20510

  1. Fibronectin tetrapeptide is target for syphilis spirochete cytadherence

    International Nuclear Information System (INIS)

    The syphilis bacterium, Treponema pallidum, parasitizes host cells through recognition of fibronectin (Fn) on cell surfaces. The active site of the Fn molecule has been identified as a four-amino acid sequence, arg-gly-asp-ser (RGDS), located on each monomer of the cell-binding domain. The synthetic heptapeptide gly-arg-gly-asp-ser-pro-cys (GRGDSPC), with the active site sequence RGDS, specifically competed with 125I-labeled cell-binding domain acquisition by T. pallidum. Additionally, the same heptapeptide with the RGDS sequence diminished treponemal attachment to HEp-2 and HT1080 cell monolayers. Related heptapeptides altered in one key amino acid within the RGDS sequence failed to inhibit Fn cell-binding domain acquisition or parasitism of host cells by T. pallidum. The data support the view that T. pallidum cytadherence of host cells is through recognition of the RGDS sequence also important for eukaryotic cell-Fn binding

  2. Fibronectin tetrapeptide is target for syphilis spirochete cytadherence

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.D.; Baseman, J.B.; Alderete, J.F.

    1985-11-01

    The syphilis bacterium, Treponema pallidum, parasitizes host cells through recognition of fibronectin (Fn) on cell surfaces. The active site of the Fn molecule has been identified as a four-amino acid sequence, arg-gly-asp-ser (RGDS), located on each monomer of the cell-binding domain. The synthetic heptapeptide gly-arg-gly-asp-ser-pro-cys (GRGDSPC), with the active site sequence RGDS, specifically competed with SVI-labeled cell-binding domain acquisition by T. pallidum. Additionally, the same heptapeptide with the RGDS sequence diminished treponemal attachment to HEp-2 and HT1080 cell monolayers. Related heptapeptides altered in one key amino acid within the RGDS sequence failed to inhibit Fn cell-binding domain acquisition or parasitism of host cells by T. pallidum. The data support the view that T. pallidum cytadherence of host cells is through recognition of the RGDS sequence also important for eukaryotic cell-Fn binding.

  3. The analytic renormalization group

    Science.gov (United States)

    Ferrari, Frank

    2016-08-01

    Finite temperature Euclidean two-point functions in quantum mechanics or quantum field theory are characterized by a discrete set of Fourier coefficients Gk, k ∈ Z, associated with the Matsubara frequencies νk = 2 πk / β. We show that analyticity implies that the coefficients Gk must satisfy an infinite number of model-independent linear equations that we write down explicitly. In particular, we construct "Analytic Renormalization Group" linear maps Aμ which, for any choice of cut-off μ, allow to express the low energy Fourier coefficients for |νk | < μ (with the possible exception of the zero mode G0), together with the real-time correlators and spectral functions, in terms of the high energy Fourier coefficients for |νk | ≥ μ. Operating a simple numerical algorithm, we show that the exact universal linear constraints on Gk can be used to systematically improve any random approximate data set obtained, for example, from Monte-Carlo simulations. Our results are illustrated on several explicit examples.

  4. Oklo working group meeting

    International Nuclear Information System (INIS)

    Natural analogue studies have been carried out for several years in the framework of the European Community's R and D programme on radioactive waste; and within its recent fourth five-year programme on 'Management and storage of radioactive waste (1990-94)' the Community is participating in the Oklo study, natural analogue for transfer processes in a geological repository. The Oklo project is coordinated by CEA-IPSN (F) and involves laboratories from several CEA directorates (IPSN, DTA and DCC) which collaborate with other institutions from France: CREGU, Nancy; CNRS, Strasbourg and ENSMD, Fontainebleau. Moreover, institutes from non-EC member States are also taking part in the Oklo study. The second joint CEC-CEA progress meeting of the Oklo Working Group was held in April 1992 in Brussels and gave the possibility of reviewing and discussing progress made since its first meeting in February 1991 at CEA in Fontenay-aux-Roses. About 40 participants from 15 laboratories and organizations coming from France, Canada, Gabon, Japan, Sweden and the USA underline the great interest in the ongoing research activities. The meeting focused on the different tasks within the CEC-CEA Oklo project concerning (i) field survey and sampling, (ii) characterization of the source term, (iii) studies of the petrographical and geochemical system, and (iv) studies of the hydrogeological system and hydrodynamic modelling. (author) 17 papers are presented

  5. Reflexive Analysis of Groups

    Science.gov (United States)

    Lefebvre, Vladimir A.

    This chapter develops further a model I previously introduced, of an agent facing a choice between the positive and the negative poles. Here I will consider agents whose individual behavior depends on a ‘society’ compounded by all of them. Four ideas underlie the theory. The first idea is to consider relationships between the subgroups of agents, not just pairs of agents; this idea allows us to represent a decomposable graph corresponding to an agent or a group of agents as a tree of subgraphs. The second idea is to establish a correspondence between decomposable graphs and polynomials, allowing us to replace a tree of subgraphs with a tree of polynomials representing a computational process. The third idea consists of the interpretation of the tree of polynomials as an agent who has images of the self, which can have images of the self, etc. Finally, the fourth idea is putting an equation into correspondence to the agent, allowing us to find out the agent’s state. The theory is illustrated here with several examples from modern geopolitics, including scenarios of current interest.

  6. The Liabilities Management Group

    International Nuclear Information System (INIS)

    The Liabilities Management Group (LMG) was initiated by DTI. It is a cooperative forum which was set up in 1995. The current participants are DTI, UKAEA, NLM (for BNFL), MOD and Magnox Electric. The LMG was initiated to produce closer cooperation between public sector liability management organizations, achieve more cost-effective management of UK nuclear liabilities and enhance development of the UK nuclear decommissioning and waste management strategy. The objectives are to compare practices between liabilities management organizations discuss the scope for collaboration identify priority areas for possible collaboration agree action plans for exploring and undertaking such collaboration.Four task forces have been formed to look at specific areas (R and D, safety, contracts, and project management) and each reports separately to the LMG. The LMG has achieved its original aim of bringing together those with public sector liability management responsibilities. All participants feel that the LMG has been useful and that it should continue. Looking to the future, there is a continuing need for the LMG to facilitate removal of barriers to the achievement of best value for money. The LMG might also consider addressing the 'business process' elements that a liability management organization must be good at in order to define best practice in these. (author)

  7. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Beier, Eugene; /Pennsylvania U.; Butler, Joel; /Fermilab; Dawson, Sally; /Brookhaven; Edwards, Helen; /Fermilab; Himel, Thomas; /SLAC; Holmes, Stephen; /Fermilab; Kim, Young-Kee; /Fermilab /Chicago U.; Lankford, Andrew; /UC, Irvine; McGinnis, David; /Fermilab; Nagaitsev, Sergei; /Fermilab; Raubenheimer, Tor; /SLAC /Fermilab

    2007-01-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  8. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Steering Group, Fermilab; /Fermilab

    2007-12-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOvA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  9. Instrumentation Working Group Summary

    Science.gov (United States)

    Zaller, Michelle; Miake-Lye, Richard

    1999-01-01

    The Instrumentation Working Group compiled a summary of measurement techniques applicable to gas turbine engine aerosol precursors and particulates. An assessment was made of the limits, accuracy, applicability, and technology readiness of the various techniques. Despite advances made in emissions characterization of aircraft engines, uncertainties still exist in the mechanisms by which aerosols and particulates are produced in the near-field engine exhaust. To adequately assess current understanding of the formation of sulfuric acid aerosols in the exhaust plumes of gas turbine engines, measurements are required to determine the degree and importance of sulfur oxidation in the turbine and at the engine exit. Ideally, concentrations of all sulfur species would be acquired, with emphasis on SO2 and SO3. Numerous options exist for extractive and non-extractive measurement of SO2 at the engine exit, most of which are well developed. SO2 measurements should be performed first to place an upper bound on the percentage of SO2 oxidation. If extractive and non-extractive techniques indicate that a large amount of the fuel sulfur is not detected as SO2, then efforts are needed to improve techniques for SO3 measurements. Additional work will be required to account for the fuel sulfur in the engine exhaust. Chemical Ionization Mass Spectrometry (CI-MS) measurements need to be pursued, although a careful assessment needs to be made of the sampling line impact on the extracted sample composition. Efforts should also be placed on implementing non-intrusive techniques and extending their capabilities by maximizing exhaust coverage for line-of-sight measurements, as well as development of 2-D techniques, where feasible. Recommendations were made to continue engine exit and combustor measurements of particulates. Particulate measurements should include particle size distribution, mass fraction, hydration properties, and volatile fraction. However, methods to ensure that unaltered

  10. 2010 Chemical Working Group Status

    Science.gov (United States)

    Reid, Concha M.

    2010-01-01

    The Steering Group for the Interagency Advanced Power Group (IAPG) held their business meeting on November 30-December 1st in McLean, Virginia. Status reports were presented from each of the IAPG's Working Groups. These charts contain a brief summary of the IAPG Chemical Working Group's activities during 2010 and its plans for 2011.

  11. A Typology for Finite Groups

    Science.gov (United States)

    Tou, Erik R

    2013-01-01

    This project classifies groups of small order using a group's center as the key feature. Groups of a given order "n" are typed based on the order of each group's center. Students are led through a sequence of exercises that combine proof-writing, independent research, and an analysis of specific classes of finite groups…

  12. About Hebei Jianxin Construction Group

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Hebei Jianxin Construction (Group) Ltd. was incorporated in August 1984. As the holding company, Hebei Jianxin Construction (Group)Ltd. along with five companies under its holding, such as Baoding New Generation Real Estate Development Co., Ltd. and Baoding New Generation Property Management Co., Ltd., formed Hebei Jianxin Architectural Group (hereafter, the Group).

  13. Anomaly-safe discrete groups

    International Nuclear Information System (INIS)

    We show that there is a class of finite groups, the so-called perfect groups, which cannot exhibit anomalies. This implies that all non-Abelian finite simple groups are anomaly-free. On the other hand, non-perfect groups generically suffer from anomalies. We present two different ways that allow one to understand these statements

  14. Group B Streptococcus and Pregnancy

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ105 PREGNANCY Group B Strep and Pregnancy • What is group B streptococcus (GBS)? • What does it mean to be ... a planned cesarean birth? •Glossary What is group B streptococcus (GBS)? Group B streptococcus is one of ...

  15. Holographic renormalization group

    International Nuclear Information System (INIS)

    The holographic renormalization group (RG) is reviewed in a self-contained manner. The holographic RG is based on the idea that the radial coordinate of a space-time with asymptotically AdS geometry can be identified with the RG flow parameter of boundary field theory. After briefly discussing basic aspects of the AdS/CFT correspondence, we explain how the concept of the holographic GR emerges from this correspondence. We formulate the holographic RG on the basis of the Hamilton-Jacobi equations for bulk systems of gravity and scalar fields, as introduced by de Boer, Verlinde and Verlinde. We then show that the equations can be solved with a derivative expansion by carefully extracting local counterterms from the generating functional of the boundary field theory. The calculational methods used to obtain the Weyl anomaly and scaling dimensions are presented and applied to the RG flow from the N = 4 SYM to an N = 1 superconformal fixed point discovered by Leigh and Straussler. We further discuss the relation between the holographic RG and the noncritical string theory and show that the structure of the holographic RG should persist beyond the supergravity approximation as a consequence of the renormalizability of the nonlinear σ-model action of noncritical strings. As a check, we investigate the holographic RG structure of higher-derivative systems. We show that such systems can also be analyzed based on the Hamilton-Jacobi equations and that the behavior of bulk fields are determined solely by their boundary values. We also point out that higher-derivative gravity systems give rise to new multicritical points in the parameter space of boundary field theories. (author)

  16. ASYNCHRONOUS ELECTRONIC DISCUSSION GROUP:

    Directory of Open Access Journals (Sweden)

    Tina Lim Swee KIM

    2007-01-01

    Full Text Available This paper examines the practice of online discussion in a course specially tailored for in-service teachers who are pursuing their basic degree qualification at a teacher training institute. Analyses of postings to the asynchronous electronic discussion group were made according to the type of postings as proposed by Poole (2000. Four focus areas were looked into, that is, content, technical, procedural, or non-academic. Analyses were done for each quarter of the 12 weeks of interaction. At the end of the learners’ participation in the EDG and before their end-of-course examination, the participants were then given a paper-based questionnaire asking their perceptions on the use of EDG as part of their coursework on the whole. Six aspects of EDG were examined, these are;Ø technical aspects, Ø motivation to use the EDG, Ø quality of interaction, Ø tutor’s response, Ø perceived learning, and Ø attitude towards EDG. Analyses on postings for the EDG showed that the bulk of the postings were made in the last quarter of the online discussions. Further, 97.8% of the postings were on content and the types of content posting registered were predominantly questions (41.19% and those that sought clarification/elaboration (37.48%. Findings from this study suggest that overall the participants were satisfied with the six aspects of EDG examined. The aspect that recorded the highest mean was ‘motivation to read tutor’s responses’ whilst the lowest mean (and the only one with negative perception was for ‘worthiness of time spent on online discussions’.

  17. Graph-Constrained Group Testing

    OpenAIRE

    M. Cheraghchi; A. Karbasi; S. Mohajer; Saligrama, V.

    2012-01-01

    Non-adaptive group testing involves grouping arbitrary subsets of $n$ items into different pools. Each pool is then tested and defective items are identified. A fundamental question involves minimizing the number of pools required to identify at most $d$ defective items. Motivated by applications in network tomography, sensor networks and infection propagation, a variation of group testing problems on graphs is formulated. Unlike conventional group testing problems, each group here must confo...

  18. Embeddings into Thompson's group V and coCF groups

    OpenAIRE

    Bleak, Collin; Matucci, Francesco; Neunhöffer, Max

    2016-01-01

    Lehnert and Schweitzer show in [21] that R. Thompson's group V is a co-context-free (coCF ) group, thus implying that all of its finitely generated subgroups are also coCF groups. Also, Lehnert shows in his thesis that V embeds inside the coCF group QAut(T2;c), which is a group of particular bijections on the vertices of an infinite binary 2-edge-colored tree, and he conjectures that QAut(T2;c) is a universal coCF group. We show that QAut(T2;c) embeds into V , and thus obtain a new form for L...

  19. Groups possessing extensive hierarchical decompositions

    CERN Document Server

    Januszkiewicz, T; Leary, I J

    2009-01-01

    Kropholler's class of groups is the smallest class of groups which contains all finite groups and is closed under the following operator: whenever $G$ admits a finite-dimensional contractible $G$-CW-complex in which all stabilizer groups are in the class, then $G$ is itself in the class. Kropholler's class admits a hierarchical structure, i.e., a natural filtration indexed by the ordinals. For example, stage 0 of the hierarchy is the class of all finite groups, and stage 1 contains all groups of finite virtual cohomological dimension. We show that for each countable ordinal $\\alpha$, there is a countable group that is in Kropholler's class which does not appear until the $\\alpha+1$st stage of the hierarchy. Previously this was known only for $\\alpha= 0$, 1 and 2. The groups that we construct contain torsion. We also review the construction of a torsion-free group that lies in the third stage of the hierarchy.

  20. Secure Group Communications for Large Dynamic Multicast Group

    Institute of Scientific and Technical Information of China (English)

    Liu Jing; Zhou Mingtian

    2003-01-01

    As the major problem in multicast security, the group key management has been the focus of research But few results are satisfactory. In this paper, the problems of group key management and access control for large dynamic multicast group have been researched and a solution based on SubGroup Secure Controllers (SGSCs) is presented, which solves many problems in IOLUS system and WGL scheme.

  1. Infinitesimal group schemes as iterative differential Galois groups

    OpenAIRE

    Maurischat, Andreas

    2009-01-01

    This article is concerned with Galois theory for iterative differential fields (ID-fields) in positive characteristic. More precisely, we consider purely inseparable Picard-Vessiot extensions, because these are the ones having an infinitesimal group scheme as iterative differential Galois group. In this article we prove a necessary and sufficient condition to decide whether an infinitesimal group scheme occurs as Galois group scheme of a Picard-Vessiot extension over a given ID-field or not. ...

  2. Ornstein-Uhlenbeck semi-groups on stratified groups

    CERN Document Server

    Lust-Piquard, Francoise

    2009-01-01

    We consider, in the setting of stratified groups G, two analogues of the Ornstein-Uhlenbeck semi-group, namely Markovian diffusion semi-groups acting on $L^q(pd g)$, whose invariant density $p$ is a heat kernel at time 1 on G.

  3. Structuring the Group Experience: A Format for Designing Psychoeducational Groups.

    Science.gov (United States)

    Furr, Susan R.

    2000-01-01

    Presents six-step model for moving from a general statement of purpose to a psychoeducational group design that includes didactic content, experiential activities, and processing. By following this model the group facilitator will be able to develop a psychoeducational group that provides a logical sequence of learning activities fostering…

  4. An Exploration of Group and Member Development in Experiential Groups

    Science.gov (United States)

    Ohrt, Jonathan H.; Prochenko, Yulia; Stulmaker, Hayley; Huffman, David; Fernando, Delini; Swan, Karrie

    2014-01-01

    In this phenomenological study, we explored 52 group members' development in experiential groups. Specifically, participants completed 10 weekly journal reflections about their experiences as members and also reflected on the group's overall development. Four overall themes--exploration, transition, working, closure--as well as multiple…

  5. PI-groups and PI-representations of groups

    OpenAIRE

    Aladova, E.; Plotkin, B.

    2009-01-01

    It is well known that many famous Burnside-type problems have positive solutions for PI-groups and PI-algebras. In the present article we also consider various Burnside-type problems for PI-groups and PI-representations of groups.

  6. Quantization on nilpotent Lie groups

    CERN Document Server

    Fischer, Veronique

    2016-01-01

    This book presents a consistent development of the Kohn-Nirenberg type global quantization theory in the setting of graded nilpotent Lie groups in terms of their representations. It contains a detailed exposition of related background topics on homogeneous Lie groups, nilpotent Lie groups, and the analysis of Rockland operators on graded Lie groups together with their associated Sobolev spaces. For the specific example of the Heisenberg group the theory is illustrated in detail. In addition, the book features a brief account of the corresponding quantization theory in the setting of compact Lie groups. The monograph is the winner of the 2014 Ferran Sunyer i Balaguer Prize.

  7. Saving Face and Group Identity

    DEFF Research Database (Denmark)

    Eriksson, Tor; Mao, Lei; Villeval, Marie-Claire

    2015-01-01

    Are people willing to sacrifice resources to save one's and others' face? In a laboratory experiment, we study whether individuals forego resources to avoid the public exposure of the least performer in their group. We show that a majority of individuals are willing to pay to preserve not only...... their self- but also other group members' image. This behavior is frequent even in the absence of group identity. When group identity is more salient, individuals help regardless of whether the least performer is an in-group or an out-group. This suggests that saving others' face is a strong social norm....

  8. Group analysis of differential equations

    CERN Document Server

    Ovsiannikov, L V

    1982-01-01

    Group Analysis of Differential Equations provides a systematic exposition of the theory of Lie groups and Lie algebras and its application to creating algorithms for solving the problems of the group analysis of differential equations.This text is organized into eight chapters. Chapters I to III describe the one-parameter group with its tangential field of vectors. The nonstandard treatment of the Banach Lie groups is reviewed in Chapter IV, including a discussion of the complete theory of Lie group transformations. Chapters V and VI cover the construction of partial solution classes for the g

  9. Topologies induced by group actions

    OpenAIRE

    Dobrowolski, Jan

    2014-01-01

    We introduce some canonical topologies induced by actions of topological groups on groups and rings. For $H$ being a group [or a ring] and $G$ a topological group acting on $H$ as automorphisms, we describe the finest group [ring] topology on $H$ under which the action of $G$ on $H$ is continuous. We also study the introduced topologies in the context of Polish structures. In particular, we prove that there may be no Hausdorff topology on a group $H$ under which a given action of a Polish gro...

  10. Group Lasso with Overlaps: the Latent Group Lasso approach

    CERN Document Server

    Obozinski, Guillaume; Vert, Jean-Philippe

    2011-01-01

    We study a norm for structured sparsity which leads to sparse linear predictors whose supports are unions of prede ned overlapping groups of variables. We call the obtained formulation latent group Lasso, since it is based on applying the usual group Lasso penalty on a set of latent variables. A detailed analysis of the norm and its properties is presented and we characterize conditions under which the set of groups associated with latent variables are correctly identi ed. We motivate and discuss the delicate choice of weights associated to each group, and illustrate this approach on simulated data and on the problem of breast cancer prognosis from gene expression data.

  11. Two-transitive Lie groups

    OpenAIRE

    Kramer, Linus

    2001-01-01

    Using a characterization of parabolics in reductive Lie groups due to Furstenberg, elementary properties of buildings, and some algebraic topology, we give a new proof of Tits' classification of 2-transitive Lie groups.

  12. Opechowski's theorem and commutator groups

    International Nuclear Information System (INIS)

    It is shown that the conditions of application of Opechowski's theorem for double groups of subgroups of O(3) are directly associated to the structure of their commutator groups. Some characteristics of the structure of classes are also discussed. (Author)

  13. Cognitive Development and Group Stages.

    Science.gov (United States)

    Saidla, Debie D.

    1990-01-01

    Attempts to integrate Perry's (1970) scheme of the cognitive development of college students with a model of group development adapted by Waldo (1985) based on Tuckman's (1965) formulation of developmental group stages. (Author)

  14. Group process among novice students.

    Science.gov (United States)

    Blumkin, M K

    1996-03-01

    This paper explores the experiences of a group of registered nurses returning to graduate school. The organizing framework used is an integration of Tuckman and Jensen's group process theory and Benner's novice to expert model. PMID:8716180

  15. Alternating Quotients of Fuchsian Groups

    OpenAIRE

    Everitt, Brent

    1999-01-01

    It is shown that any finitely generated non-elementary Fuchsian group has among its homomorphic images all but finitely many of the alternating groups. This settles in the affirmative a conjecture of Graham Higman.

  16. On -supersolvability of finite groups

    Indian Academy of Sciences (India)

    Izabela Agata Malinowska

    2015-05-01

    A number of authors have studied the structure of a group under the assumption that some subgroups of are well located in . We will obtain some new criteria of -supersolvability and -nilpotency of groups.

  17. Criminal groups and criminal subculture

    OpenAIRE

    Romanova N.M.

    2013-01-01

    The paper provides a classification of criminal groups, structured by the following parameters: a) operation mode (secret/open), b) law-enforcement and administrative support (presence/absence). We describe four types of criminal groups: a) legitimized criminal organization, b) secret criminal organization engaged in illegal business, c) secret general crime group, and d) general crime group operating openly. The four types differ in the content of criminal subculture. Modern criminal subcult...

  18. Costs of Control in Groups

    OpenAIRE

    Riener, Gerhard; Wiederhold, Simon

    2011-01-01

    This paper explores the role of social groups in explaining the reaction to control.We propose a simple model with a principal using control devices and a controlledagent, which incorporates the existence of social groups. Testing experimentally theconjectures derived from the model and related literature, we find that agents in socialgroups (i) perform more than other (no-group) agents; (ii) expect less control thanno-group agents; (iii) decrease their performance substantially when actual c...

  19. Homogeneity in the free group

    CERN Document Server

    Perin, Chloé

    2010-01-01

    We show that any non abelian free group $\\F$ is strongly $\\aleph_0$-homogeneous, i.e. that finite tuples of elements which satisfy the same first-order properties are in the same orbit under $\\Aut(\\F)$. We give a characterization of elements in finitely generated groups which have the same first-order properties as a primitive element of the free group. We deduce as a consequence that most hyperbolic surface groups are not $\\aleph_0$-homogeneous.

  20. Modelling group dynamic animal movement

    OpenAIRE

    Langrock, Roland; Hopcraft, Grant; Blackwell, Paul; Goodall, Victoria; King, Ruth; Niu, Mu; Patterson, Toby; Pedersen, Martin; Skarin, Anna; Schick, Robert Schilling

    2013-01-01

    1). Group dynamics are a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognized, particularly in order to differentiate the role of social forces in individual movement from environmental factors. However, to date, practical statistical methods, which can include group dynamics in animal movement models, have been lacking. 2). We consider a flexible modelling framework that distinguishes a group-level ...

  1. R-groups and parameters

    OpenAIRE

    Ban, Dubravka; Goldberg, David

    2011-01-01

    For classical groups we show the isomorphism of the Knapp-Stein $R$-group, which describes the structure of parabolically induced representations, and the Arthur $R$-group of the parameter associated to the inducing representation by the local Langlands conjecture. We do this in the case of inducing from discrete series representations. In the case of unitary groups we show this isomorphism under a mild assumption on the parameter, which we show holds in at least half the cases.

  2. Group Norms and Consumer Behaviour

    OpenAIRE

    Pillai, Rajasekharan; Rajan, Jainey S.; Variyamveettil, Sunitha; Mathew, Dhanu E.; Nath, Subodh S.

    2011-01-01

    The impact of group norms on forming consumer behaviour is an important attribute of man’s social life. The market segmentation principles acknowledge the presence of this phenomenon. People belong to different age group, professional status, income levels, educational status etc. are seemed to display some specific consumer behaviour that can be attributed to a particular group. The present study attempts to find the influence of certain selected group norms on consumption pattern.

  3. Group Theory: It's a SNAP.

    Science.gov (United States)

    Huetinck, Linda

    1996-01-01

    Introduces concepts of modern algebraic group theory in the form of a game. Peg boards and rubber bands represent nonnumerical group elements and are manipulated under the operation of reorienting a regular polygon. Symmetry groups are used to explore set properties, as well as commutative and noncommutative operations. (CMS)

  4. Internal communication in corporate groups

    OpenAIRE

    Grzesik, Katarzyna

    2015-01-01

    This chapter is dedicated to internal communication in corporate groups. It discusses internal communication systems operating in the explored corporate groups and their significance for effective human resources management in those organisations. The chapter presents both the theoretical analysis based on the results of literature studies, and empirical research carried out in the explored groups. Narodowe Centrum Nauki Katarzyna Grzesik

  5. The Variety of Group Learning

    Institute of Scientific and Technical Information of China (English)

    HaoYanyan; YuZhihao

    2004-01-01

    With the rapid enrollment expansion in the recent years,the author feels it urgent to reform the traditional group work,and therefore to form a new and more effective pattern of group learning. The new of group word is based on the principles of cooperation and that of the task with the more flexible marking system.

  6. Defense Mechanisms in Group Counseling.

    Science.gov (United States)

    Clark, Arthur J.

    1992-01-01

    Presents considerations and strategies for conceptualizing, recognizing, and modifying defense mechanisms through the group counseling process. Provides awareness of defense mechanisms in planning for and implementation of group counseling, describes interaction patterns for identifying defenses among group participants, and clarifies modification…

  7. K-Kolmogorov homology groups

    International Nuclear Information System (INIS)

    In the present work we use the idea of the K-groups to define the K-Kolmogorov homology groups, and their induced homomorphisms and boundary operators for the case of a pair of discrete coefficient groups, where K denotes a locally-finite simplicial complex. Moreover, we prove that our homology construction is exact. (author)

  8. Group Counselling for Problem Gambling.

    Science.gov (United States)

    Coman, Gregory J.; Evans, Barry J.; Burrows, Graham D.

    2002-01-01

    Group counseling has been used to assist individuals to overcome difficulties associated with problem gambling behavior; however, there are few reports of this application in the clinical and research literature. This paper provides a brief review of group counseling, and describes the application of group counseling to assist individuals with…

  9. Torsion units in group rings

    OpenAIRE

    Bist, Vikas

    1992-01-01

    Let U(RG) be the unit group of the group ring RG. In this paper we study group rings RG whose support elements of every torsion unit are torsion, where R is either the ring of integers Z or a field K.

  10. Hierarchical classification of social groups

    OpenAIRE

    Витковская, Мария

    2001-01-01

    Classification problems are important for every science, and for sociology as well. Social phenomena, examined from the aspect of classification of social groups, can be examined deeper. At present one common classification of groups does not exist. This article offers the hierarchical classification of social group.

  11. Ultrafilters and topologies on groups

    CERN Document Server

    Zelenyuk, Yevhen

    2011-01-01

    This book presents the relationship between ultrafilters and topologies on groups. It shows how ultrafilters are used in constructing topologies on groups with extremal properties and how topologies on groups serve in deriving algebraic results aboutultrafilters. Topics covered include: topological and left topological groups, ultrafilter semigroups, local homomorphisms and automorphisms, subgroups and ideal structure of ßG, almost maximal spaces and projectives of finite semigroups, resolvability of groups. This is a self-contained book aimed at graduate students and researchers working in to

  12. Invariant operators of inhomogeneous groups

    International Nuclear Information System (INIS)

    The problems concerning the invariant operators of the W(p, q) Weyl group of arbitrary dimension are considered. The Weyl group relative invariants, which do not contain the dilatation operators and which are the absolute invariants of the ISO (p, q) group, are searched for. The invariant operators of the Weyl group are represented in the form of the ratio of the Cazimir operators of the inhomogeneous pseudoorthogonal subgroup. It is shown that all the invariant operators of the W(p, q) Weyl group are rational and their number is [p+q-1/2

  13. Modelling group dynamic animal movement

    DEFF Research Database (Denmark)

    Langrock, Roland; Hopcraft, J. Grant C.; Blackwell, Paul G.;

    2014-01-01

    , to date, practical statistical methods which can include group dynamics in animal movement models have been lacking. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual...... makes its movement decisions relative to the group centroid. The basic idea is framed within the flexible class of hidden Markov models, extending previous work on modelling animal movement by means of multi-state random walks. While in simulation experiments parameter estimators exhibit some bias...... in an encamped state. Though the attraction to the group centroid is relatively weak, our model successfully captures group-influenced movement dynamics. Specifically, as compared to a regular mixture of correlated random walks, the group dynamic model more accurately predicts the non-diffusive behaviour...

  14. Defining and Classifying Interest Groups

    DEFF Research Database (Denmark)

    Baroni, Laura; Carroll, Brendan; Chalmers, Adam;

    2014-01-01

    The interest group concept is defined in many different ways in the existing literature and a range of different classification schemes are employed. This complicates comparisons between different studies and their findings. One of the important tasks faced by interest group scholars engaged in...... large-N studies is therefore to define the concept of an interest group and to determine which classification scheme to use for different group types. After reviewing the existing literature, this article sets out to compare different approaches to defining and classifying interest groups with a sample...... cluster actors according to a number of key background characteristics and second assess how the categories of the different interest group typologies relate to these clusters. We demonstrate that background characteristics do align to a certain extent with certain interest group types but also find...

  15. Sur le groupe de Cremona et ses sous-groupes

    OpenAIRE

    Usnich, Alexandr

    2008-01-01

    Ce travail peut être divisé en trois partie: 1. Théorie des groupes. Il s'agit ici d'une étude de la structure du groupe T de Thompson. On explique la notion de la mutation linéaire par morceaux et on obtient la nouvelle présentation de ce groupe en termes des génerateurs et relations. 2. Géometrie birationnelle. On étudie en détail le groupe de Cremona qui est un groupe des automorphismes birationnels du plan projectif. En particulier on s'interesse à son sous-groupe Symp des elements qui pr...

  16. Isomorphic Commutative Group Algebras of p-Mixed Warfield Groups

    Institute of Scientific and Technical Information of China (English)

    Peter V.DANCHEV

    2005-01-01

    Let G be a p-mixed Warfield Abelian group and F a field of char F = p ≠ 0. It is proved that if for any group H the group algebras FH and FG are F-isomorphic, then H is isomorphic to G.This presentation enlarges a result of W. May argued when G is p-local Warfield Abelian and published in Proc. Amer. Math. Soc. (1988).

  17. Group Members’ Assessment of Their Conductor in Small Analytic Group

    OpenAIRE

    Vlastelica, Mirela; Urlić, Ivan

    2004-01-01

    In this pilot study the authors present the group members’ assessment of their conductor in group analysis – the treatment conducted in accordance with concept »groupas- a-whole« of S. H. Foulkes. There will be presented the results obtained by scale for evaluation of characteristics of the group therapist. In the scale, developed by the authors of the study, there were 30 items and by factorial analysis it gave three interpretable factors: authenticity, empathy and distrust. B...

  18. Developing HR processes at group level: Case Halton Group

    OpenAIRE

    Sorvari, Iina

    2016-01-01

    The case company, Halton Group, as many other global technology companies worldwide, is investigating the possibility of taking a global human resource information system into use globally. In order to have a successful implementation process for the project, it is essential to have human resource processes described at the group level. This study aimed to develop the key HR processes in a global technology organization at the group level in order to enable modelling the group’s HR proce...

  19. Linear groups as right multiplication groups of quasifields

    OpenAIRE

    Nagy, Gábor P.

    2012-01-01

    For quasifields, the concept of parastrophy is slightly weaker than isotopy. Parastrophic quasifields yield isomorphic translation planes but not conversely. We investigate the right multiplication groups of finite quasifields. We classify all quasifields having an exceptional finite transitive linear group as right multiplication group. The classification is up to parastrophy, which turns out to be the same as up to the isomorphism of the corresponding translation planes.

  20. Mapping class group representations from Drinfeld doubles of finite groups

    CERN Document Server

    Fjelstad, Jens

    2015-01-01

    We investigate representations of mapping class groups of surfaces that arise from the untwisted Drinfeld double of a finite group G, focusing on surfaces without marked points or with one marked point. We obtain concrete descriptions of such representations in terms of finite group data. This allows us to establish various properties of these representations. In particular we show that they have finite images, and that for surfaces of genus at least 3 their restriction to the Torelli group is non-trivial iff G is non-abelian.