478 research outputs found

    Twisted algebra R-matrices and S-matrices for bn(1)b_n^{(1)} affine Toda solitons and their bound states

    Full text link
    We construct new Uq(a2n1(2))U_q(a^{(2)}_{2n-1}) and Uq(e6(2))U_q(e^{(2)}_6) invariant RR-matrices and comment on the general construction of RR-matrices for twisted algebras. We use the former to construct SS-matrices for bn(1)b^{(1)}_n affine Toda solitons and their bound states, identifying the lowest breathers with the bn(1)b^{(1)}_n particles.Comment: Latex, 24 pages. Various misprints corrected. New section added clarifying relationship between R-matrices and S-matrice

    The NMR side-chain assignments and solution structure of enzyme IIBcellobiose of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli

    Get PDF
    The assignment of the side-chain Nh IR resonances and the determination of the three-dimensional solution structure of the C10S mutant of enzyme IIBcellobiose (IIBcel) of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli are presented. The side-chain resonances were assigned nearly completely using a variety of mostly heteronuclear NMR experiments, including HCCH-TOCSY, HCCH-COSY, and COCCH-TOCSY experiments as well as CBCACOHA, CBCA(CO)NH, and HBHA(CBCA)(CO)NH experiments.In order to obtain the three-dimensional structure, NOE data were collected from N-15-NOESY-HSQC, C-13-HSQC-NOESY, and 2D NOE experiments. The distance restraints derived from these NOE data were used in distance geometry calculations followed by molecular dynamics and simulated annealing protocols. In an iterative procedure, additional NOE assignments were derived from the calculated structures and new structures were calculated. The final set of structures, calculated with approximately 2000 unambiguous and ambiguous distance restraints, has an rms deviation of 1.1 Angstrom, on C alpha atoms. IIBcel consists of a four stranded parallel beta-sheet, in the order 2134. The sheet is flanked with two and three alpha-helices on either side. Residue 10, a cysteine in the wild-type enzyme, which is phosphorylated during the catalytic cycle, is located at the end of the first beta-strand. A loop that is proposed to be involved in the binding of the phosphoryl-group follows the cysteine. The loop appears to be disordered in the unphosphorylated state.</p

    Flight of the dragonflies and damselflies

    Get PDF
    This work is a synthesis of our current understanding of the mechanics, aerodynamics and visually mediated control of dragonfly and damselfly flight, with the addition of new experimental and computational data in several key areas. These are: the diversity of dragonfly wing morphologies, the aerodynamics of gliding flight, force generation in flapping flight, aerodynamic efficiency, comparative flight performance and pursuit strategies during predatory and territorial flights. New data are set in context by brief reviews covering anatomy at several scales, insect aerodynamics, neuromechanics and behaviour. We achieve a new perspective by means of a diverse range of techniques, including laser-line mapping of wing topographies, computational fluid dynamics simulations of finely detailed wing geometries, quantitative imaging using particle image velocimetry of on-wing and wake flow patterns, classical aerodynamic theory, photography in the field, infrared motion capture and multi-camera optical tracking of free flight trajectories in laboratory environments. Our comprehensive approach enables a novel synthesis of datasets and subfields that integrates many aspects of flight from the neurobiology of the compound eye, through the aeromechanical interface with the surrounding fluid, to flight performance under cruising and higher-energy behavioural modes

    Annual report on surveillance of respiratory infectious diseases 2013, the Netherlands

    Get PDF
    Het griepseizoen (influenza) 2013/2014 was erg mild, na de uitzonderlijk langdurende epidemie in het seizoen 2012/2013. Ook was het een mild seizoen wat betreft het aantal mensen dat een longontsteking (pneumonie) opliep. In 2013 waren er geen grote uitbraken van de meldingsplichtige luchtweginfectieziekten legionellose (308 meldingen), papegaaienziekte (psittacose; 51 meldingen), Q-koorts (19 meldingen) en tuberculose (848 meldingen). Deze aantallen waren in het verslagjaar vergelijkbaar of lager dan het aantal meldingen in voorgaande jaren. Dit blijkt uit de jaarlijkse surveillance luchtweginfectieziekten 2013 van het RIVM. Griep en longontsteking leiden tot veel ziekenhuisopnames en sterfte in Nederland, waardoor het RIVM ze actief volgt. In vergelijking met griep komen de meldingsplichtige luchtweginfecties in Nederlands maar weinig voor. Ze zijn meldingsplichtig, omdat tijdige maatregelen, zoals de besmettingsbron opsporen, belangrijk kunnen zijn om uitbraken of verdere verspreiding van de ziekte te voorkomen. Het RIVM volgt ook potentieel gevaarlijke nieuwe luchtweginfecties die elders in de wereld voorkomen. In mei 2014 werden voor het eerst in Nederland twee patiënten gediagnostiseerd met het MERS coronavirus. In het seizoen 2013/2014 lag het aantal mensen dat met griepachtige klachten bij de huisarts kwam begin 2014 gedurende vier weken boven de grens waarmee een griepepidemie wordt geduid. Bij de patiënten met griepachtige klachten kwam naast influenzavirus vaak RSV (respiratoir syncytieel virus) en neusverkoudheid (rhinovirus) voor. Er kwamen minder mensen met een longontsteking bij de huisarts dan voorgaande seizoenen, maar het aantal longontstekingpatiënten in verpleeghuizen bleef gelijk.The 2013/2014 influenza season was extremely mild in the Netherlands, compared to the exceptionally long-lasting epidemic in 2012/2013. In addition, the number of pneumonia patients and overall mortality, possible complications of influenza, were low. In 2013, no major outbreaks of the notifiable respiratory infectious diseases legionellosis (308 notifications), psittacosis (51 notifications), Q-fever (19 notifications) and tuberculosis (848 notifications) occurred. These incidences are either comparable to or lower than preceding years. These are the outcomes of the annual report: 'Surveillance of respiratory infectious diseases 2013, the Netherlands', published by the Dutch National Institute for Public Health and the Environment (RIVM). Influenza and pneumonia are an important cause of hospital admissions and death in the Netherlands, a reason for the RIVM to actively monitor these diseases. In comparison to influenza, notifiable respiratory infectious diseases only rarely occur. These diseases are notifiable, as timely measures like source finding, are important for preventing outbreaks and/ or ongoing transmission of the disease. The RIVM also monitors potential threats to public health from new (worldwide) respiratory infections. In May 2014, the first two cases of MERS coronavirus were diagnosed in the Netherlands. During the 2013/2014 influenza-season, the number of patients with influenza-like illness (ILI) consulting a general practitioner, was above the threshold set for an influenza epidemic for four weeks at the beginning of 2014. In nose and throat samples of ILI-patients, RSV (respiratory syncytial virus) and rhinovirus were found in addition to the influenza virus. During the 2013/2014 influenza-season, fewer patients consulted the general practitioner for pneumonia than in previous years, however the number of pneumonia patients in nursing homes was similar.Ministerie van VW

    Experienced discrimination amongst European old citizens

    Get PDF
    This study analyses the experienced age discrimination of old European citizens and the factors related to this discrimination. Differences in experienced discrimination between old citizens of different European countries are explored. Data from the 2008 ESS survey are used. Old age is defined as being 62 years or older. The survey data come from 28 European countries and 14,364 old-age citizens. Their average age is 72 years. Factor analysis is used to construct the core variable ‘experienced discrimination’. The influence of the independent variables on experienced discrimination is analysed using linear regression analysis. About one-quarter of old European citizens sometimes or frequently experience discrimination because of their age. Gender, education, income and belonging to a minority are related to experienced age discrimination. Satisfaction with life and subjective health are strongly associated with experienced age discrimination, as is trust in other people and the seriousness of age discrimination in the country. Large, significant differences in experienced discrimination due to old age exist between European countries. A north-west versus south-east European gradient is found in experienced discrimination due to old age. The socio-cultural context is important in explaining experienced age discrimination in old European citizens. Old-age discrimination is experienced less frequently in countries with social security arrangements. Further research is needed to understand the variation in (old) age discrimination between European countries. Measures recommended include increasing public awareness about the value of ageing for communities and changing public attitudes towards the old in a positive way
    corecore