44 research outputs found

    Three kinematical methods to identify local galactic structures

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    Method one: by combining a sampling parameter related to an isolating integral of the stellar motion, an optimisation of the mixture approach, and a maximisation of the partition entropy for the constituent populations of the stellar sample. Method two: by segregating into different kinematical components in terms of the stellar orbital parameters. Method three: by approaching a maximum entropy velocity distribution to samples selected in terms of stellar eccentricity layers. Working samples: HIPPARCOS and Geneva-Copenhagen survey catalog. Results: kinematical characterisation of large-scale structures, such as thin disc, thick disc and halo, and identification of small-scale structures, such as moving groups in the solar neighbourhood. Consequences: confirmation of the Titius-Bode-like law for radial velocity dispersions and explanation of the apparent vertex deviation of the disc from the swinging of two major kinematic groups around the LSR, by predicting a continuously changing orientation of the disc pseudo ellipsoid.Postprint (published version

    Galactic subsystems on the basis of cumulative distribution of space velocities

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    A sample containing 4,6144,614 stars with available space velocities and high-quality kinematical data from the Arihip Catalogue is formed. For the purpose of distinguishing galactic subsystems the cumulative distribution of space velocities is studied. The fractions of the three subsystems are found to be: thin disc 92\%, thick disc 6\% and halo 2\%. These results are verified by analysing the elements of velocity ellipsoids and the shape and size of the galactocentric orbits of the sample stars, i.e. the planar and vertical eccentricities of the orbits

    Analysis of mortality in patients with early diagnosis of acute aortic dissection

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    Objective. The aim of this study was to analyze the frequency of acute aortic dissection, its clinical manifestations, treatment modalities, and mortality. Methods. During the years of 2008 and 2009 twenty six patients with acute aortic dissection (14 women with mean age 61.9±14.8 years and 12 men, mean age 64.8±10.0 years) were treated in the Internal medicine department of the Center for Emergency Medicine, Clinical Center Kragujevac. Results. The predominant symptoms in the majority of patients were pain in the chest and abdomen, but five patients were dominated by symptoms of central nervous system (headache, speech disturbances, hemiparesis, loss of consciousness, etc.). The working diagnosis of aortic dissection was made after physical examination in seven patients (five had already had aneurysms of the aorta), and after an ultrasound examination in fourteen patients. Only two patients were operated in the reference institution outside the Clinical Center Kragujevac. In nine patients the situation stabilized with medication treatment, and lethal outcome was recorded in 15 patients (57.7%), eleven of whom in the Center for Emergency Medicine - within the first six hours of hospitalization, and four patients in other clinics of CC Kragujevac. Conclusion. Patients with acute aortic dissection need to be diagnosed and hospitalized in a multidisciplinary and standardized approach so that the critical period between making the diagnosis and the surgical treatment is shorter and the hospital service and care for the patients is better in terms of adequate transport to the institution in which urgent surgical interventions can be performed

    Three kinematical methods to identify local galactic structures

    No full text
    Method one: by combining a sampling parameter related to an isolating integral of the stellar motion, an optimisation of the mixture approach, and a maximisation of the partition entropy for the constituent populations of the stellar sample. Method two: by segregating into different kinematical components in terms of the stellar orbital parameters. Method three: by approaching a maximum entropy velocity distribution to samples selected in terms of stellar eccentricity layers. Working samples: HIPPARCOS and Geneva-Copenhagen survey catalog. Results: kinematical characterisation of large-scale structures, such as thin disc, thick disc and halo, and identification of small-scale structures, such as moving groups in the solar neighbourhood. Consequences: confirmation of the Titius-Bode-like law for radial velocity dispersions and explanation of the apparent vertex deviation of the disc from the swinging of two major kinematic groups around the LSR, by predicting a continuously changing orientation of the disc pseudo ellipsoid

    Measuring Potential of Preschool Facility Staff to Prevent Early Childhood Caries

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    © 2016 Acta Facultatis Medicae Naissensis. The aim of this study was to investigate the possible potential of preschool staff through a newly designed questionnaire and evaluate their role in the prevention of early childhood caries (EEC) in Serbia where extremely high prevalence of this preventable disease was recorded. We preformed a cross-sectional study of 268 preschool staff using specially prepared semi-structured questionnaire for measuring potential of secondary children's caregivers to prevent EEC. The questionnaire was tested on a pilot sample and after that all collected data were analyzed trough construction of correlation matrix with the evaluation of the value of each question, reliability testing, factorial analysis and estimating of its validity using SPSS software. The tested questionnaire had good internal consistency based on the Cronbach's alpha coefficient value of 0.873 calculated directly and similar value (0.899) after applied Spearman-Brown prediction formula. Using exploratory factorial analysis and orthogonal rotation, we identified two domains that emerged with similar loadings (4.043 and 3.183). The first factor (domain) reflected attitudes of the study participants towards prevention of EEC, and the second factor (domain) showed behaviour of the study participants, which includes preventive actions against EEC. The total score of the questionnaire was correlated positively with oral health knowledge (Spearman's correlation coefficient 0.331, p=000) and inversely with the length of employment, where each additional year of employment decreased the total score of the questionnaire by 1.20. These findings could partially explain an extremely high prevalence of EEC in young children and indicate that preschool teachers should be more engaged in health education activities and motivation programs
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