30 research outputs found
Global Compatibility of Bi-Hamiltonian Structures on Three Dimensional Manifolds
It is shown in \cite{yazar6} that a dynamical system defined by a
nonvanishing vector field on an orientable three dimensional manifold is
globally bi-Hamiltonian if and only if the first Chern class of the normal
bundle of the given vector field vanishes, and the bi-Hamiltonian structure is
globally compatible if and only if the Bott class of the complex codimension
one foliation defined by the nonvanishing vector field vanishes. In this work,
we constructed a dynamical system on , which is globally bi-Hamiltonian,
but the Hamiltonians are not globally compatible.Comment: 12 page
Global Existence of Bi-Hamiltonian Structures on Orientable Three-Dimensional Manifolds
In this work, we show that an autonomous dynamical system defined by a nonvanishing vector field on an orientable three-dimensional manifold is globally bi-Hamiltonian if and only if the first Chern class of the normal bundle of the given vector field vanishes. Furthermore, the bi-Hamiltonian structure is globally compatible if and only if the Bott class of the complex codimension one foliation defined by the given vector field vanishes
Poisson Structures for Aristotelian Model of Three Body Motion
We present explicitly Poisson structures, for both time-dependent and
time-independent Hamiltonians, of a dynamical system with three degrees of
freedom introduced and studied by Calogero et al [2005]. For the
time-independent case, new constant of motion includes all parameters of the
system. This extends the result of Calogero et al [2009] for semi-symmetrical
motion. We also discuss the case of three bodies two of which are not
interacting with each other but are coupled with the interaction of third one
Validity and reliability of the assessment tool for Asthma (ATA) questionnaire: the ATA study
OBJECTIVES: A multicenter trial was designed to validate the “Assessment Tools for Asthma (ATA)” questionnaire, a newly developed questionnaire, which evaluates both asthma control and risk factors associated with asthma control with a single instrument. MATERIALS AND METHODS: This cross-sectional study involved 810 cases from 14 clinics in 9 Turkish cities. The ATA questionnaire and Asthma Control Test (ACT) were administered. The Visual Analog Scale (VAS) was used to evaluate the control status of 100 randomized cases. ATA is an eight-item physician-administered questionnaire. It comprises the following two sections-ATA1, assesses symptomatic control criteria, and the remaining section, queries the flre-up of asthma, control of comorbidities, treatment adherence, and inhaler technique. RESULTS: The mean scores for ATA1, ATA total, VAS, and ACT were 24.7±14.8, 53.8±19, 7.1±3, and 18.8±5.5, respectively. According to the ATA questionnaire, among all patients, 34.3% had controlled, 18.8% had partly controlled, and 46.9% had uncontrolled asthma. Furthermore, 16.6% patients had flre-ups between visits, 96.4% patients had uncontrolled comorbidity, 17% patients had irregular asthma treatment, and only 8.4% patients used the incorrect inhaler technique. The ATA questionnaire showed internal consistency (Cronbach’s alpha coeffiient=0.683). ACT, ATA1, and two specialists’ evaluations using VAS correlated strongly with the ATA total scores (Spearman correlation coeffiient (r) values: 0.776, 0.783, and 0.909, respectively; p-values: p<0.001, p<0.001, and p<0.001, respectively). According to Receiver Operating Characteristic analysis, the cut-off value of ATA was 50 (sensitivity=84.4%, specifiity=82.40%). CONCLUSION: The validated ATA questionnaire may be a practical tool for physicians in asthma management
Effectiveness of influenza vaccination for preventing influenza-related complications in people with asthma:A systematic review protocol
Peer reviewedPublisher PD
Tüberkülin testi sonuçlarının yorumlanması ülkemiz standartları ve yeni gereksinimler
Prevalence of asthmatic smokers: Turkish experience (PASTE Study)
Background: Although both asthma and smoking are major health problems worldwide, smokers are often excluded from asthma studies. Objectives: It was aimed to verify the prevalence of asthmatic smokers in Turkey and assess the effects of smoking based on clinical parameters, exacerbations and hospitalizations because of lack of national data about the prevalence of smoking among asthmatics. Methods: The study protocol was comprised of a retrospective questionnaire. The asthmatic patients were followed in the outpatient clinics of 18 tertiary hospitals selected from seven different geographical regions in Turkey. We evaluated demographic data, smoking habits, asthma-related diseases, respiratory function and emergency visits. Results: The study population included 1385 patients (M/F: 343/1042), and the mean age was 45.1±14.0 years. Current and former smoking prevalence was 11.4% and 15.1%, respectively. Smoker rates were higher in males and younger asthmatics compared with females and older asthmatics (P0.05). Conclusion: We showed that the smoking prevalence in Turkey was lower in asthmatics (11.4%) compared with the general population (44.5%). Nevertheless, every effort should be made to encourage asthmatics to stop smoking because smoking is a modifiable risk factor for adverse asthma health outcomes. © 2013 John Wiley and Sons Ltd