433 research outputs found

    Application of bifurcation theory for existence of travelling waves in examples of semilinear and quasilinear wave equations

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    Wir untersuchen wandernde Wellen für semilineare bzw. quasilineare Wellengleichungen. Wir beweisen die Existenz von speziellen wandernden Wellen, welche periodisch in der Ausbreitungsrichtung und lokalisiert in eine der orthogonalen Richtungen sind. Die Gleichungen werden durch die Maxwell-Gleichungen im optischen Fall mit Kerr-Nichtlinearität im Polarisationsfeld motiviert. Die wandernden Wellen verzweigen von den linear geführten Moden

    Traveling waves for a quasilinear wave equation

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    We consider a 2+1 dimensional wave equation appearing in the context of polarized waves for the nonlinear Maxwell equations. The equation is quasilinear in the time derivatives and involves two material functions V and Γ. We prove the existence of traveling waves which are periodic in the direction of propagation and localized in the direction orthogonal to the propagation direction. Depending on the nature of the nonlinearity coefficient Γ we distinguish between two cases: (a) Γ ∈ L∞ being regular and (b) Γ = γδ0 being a multiple of the delta potential at zero. For both cases we use bifurcation theory to prove the existence of nontrivial smallamplitude solutions. One can regard our results as a persistence result which shows that guided modes known for linear wave-guide geometries survive in the presence of a nonlinear constitutive law. Our main theorems are derived under a set of conditions on the linear wave operator. They are subsidized by explicit examples for the coefficients V in front of the (linear) second time derivative for which our results hold

    Traveling waves for a quasilinear wave equation

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    We consider a 2+12+1 dimensional wave equation appearing in the context of polarized waves for the nonlinear Maxwell equations. The equation is quasilinear in the time derivatives and involves two material functions VV and Γ\Gamma. We prove the existence of traveling waves which are periodic in the direction of propagation and localized in the direction orthogonal to the propagation direction. Depending on the nature of the nonlinearity coeffcient Γ\Gamma we distinguish between two cases: (a) ΓL°\Gamma \in L°{\infty} being regular and (b) Γ=γδ0\Gamma = \gamma\delta_0 being a multiple of the delta potential at zero. For both cases we use bifuraction theory to prove the existence of nontrivial small-amplitude solutions. One can regard our results as a persistence result which shows that guided modes known for linear wave-guide geometries survive in the presence of a nonlinear constitutive law. Our main theorems are derived under a set of conditions on the linear wave operator. They are subsidised by explicit examples for the coefficients VV in front of the (linear) second time derivative for which our results hold

    Thyrotropinoma - the case report about one of the rarest type of pituitary adenomas

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    Pituitary tumours are a significant diagnostic problem in clinical practice. Considering all the rarity of thyrotropic hormone secreting adenoma it is a diagnostic and therapeutic challenge in part due to the lack of the preoperative standards. TSH-oma, besides hyperthyroidism symptoms, might be a cause of other endocrine disorders, most often dysfunction of other tropic axes and may cause neurological symptoms associated with sella expansion. We report a case of a 49-year-old male patient with macroadenoma, overt clinical hyperthyroidism, secondary adrenal insufficiency and hypogonadotropic hypogonadism. The diagnosis of thyrotropinoma was confirmed by blood tests that revealed elevated FT3 and FT4 levels together with high TSH. Thyrotropin-releasing hormone (TRH) test was performed and  magnetic resonance imaging (MRI) imaging revealed the presence of macroadenoma. Histopathology examination confirmed the diagnosis of thyrotropic cell pituitary adenoma. The appropriate therapy for thyrotropin pituitary adenoma has not been elaborated in reports of this domain. Preoperatively the patient was prepared by long-acting somatostatin analogue (Sandostatin LAR) injections to reduce tumor size with good therapeutic effect afterwards underwent surgical transsphenoidal treatment successfully. However, specific treatment guidelines for pituitary thyrotropic tumors need to be elaborated more in details

    E-smoking among students of medicine — frequency, pattern and motivations

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    INTRODUCTION: E-smoking has become a public health problem. The objectives of this study were to assess the prevalence of e-cigarette and tobacco cigarette use; to compare the patterns of smoking; to assess the attitudes and motivations for e-cigarette use. MATERIAL AND METHODS: All 1,700 students from Faculty of Medicine (Medical University of Silesia) were invited to questionnaire based cross-sectional study about the frequency and attitudes towards the use of traditional and electronic cigarettes. RESULTS: The data were obtained from 1,318 medical students (response 77.5%) aged 22.1 ± 2.2 years. Traditional tobacco smoked 18.1%, e-cigarettes 1.3% and 2.2% were dual smokers. The overall frequency of e-smokers was 4.9% among men and 2.8% among women (p = 0.05). Compared to tobacco users in e-smokers duration of smoking was shorter (p < 0.001), the intensity of smoking was larger (p = 0.01), the number of e-cigarettes smoked daily was higher (p < 0.001). Dual smokers more frequently used tobacco cigarettes than e-cigarettes (p = 0.01) but smoked more e-cigarettes daily (p = 0.003). The choice of e-liquid depended on the flavour (50.0%), nicotine concentration (21.7%) and price (7.6%). No-nicotine e-cigarettes were used by 6.5% smokers. Dual smokers more frequently chose e-liquids with high nicotine concentration (p = 0.01). Motivations leading to e-smoking were: quitting tobacco (58.7%), less harmful impact on health (43.5%) and the price (34.8%). E-smoking as safe for health was perceived by 6.0% of respondents (35.5% in e-smokers vs. 4.9% in non e-smokers; p < 0.001). CONCLUSION: Among students of medicine, e-smoking is apparently less popular than smoking tobacco cigarettes. Respondents considered e-cigarettes to be harmful and addictive.INTRODUCTION: E-smoking has become a public health problem. The objectives of this study were to assess the prevalence of e-cigarette and tobacco cigarette use; to compare the patterns of smoking; to assess the attitudes and motivations for e-cigarette use. MATERIAL AND METHODS: All 1,700 students from Faculty of Medicine (Medical University of Silesia) were invited to questionnaire based cross-sectional study about the frequency and attitudes towards the use of traditional and electronic cigarettes. RESULTS: The data were obtained from 1,318 medical students (response 77.5%) aged 22.1 ± 2.2 years. Traditional tobacco smoked 18.1%, e-cigarettes 1.3% and 2.2% were dual smokers. The overall frequency of e-smokers was 4.9% among men and 2.8% among women (p = 0.05). Compared to tobacco users in e-smokers duration of smoking was shorter (p < 0.001), the intensity of smoking was larger (p = 0.01), the number of e-cigarettes smoked daily was higher (p < 0.001). Dual smokers more frequently used tobacco cigarettes than e-cigarettes (p = 0.01) but smoked more e-cigarettes daily (p = 0.003). The choice of e-liquid depended on the flavour (50.0%), nicotine concentration (21.7%) and price (7.6%). No-nicotine e-cigarettes were used by 6.5% smokers. Dual smokers more frequently chose e-liquids with high nicotine concentration (p = 0.01). Motivations leading to e-smoking were: quitting tobacco (58.7%), less harmful impact on health (43.5%) and the price (34.8%). E-smoking as safe for health was perceived by 6.0% of respondents (35.5% in e-smokers vs. 4.9% in non e-smokers; p < 0.001). CONCLUSION: Among students of medicine, e-smoking is apparently less popular than smoking tobacco cigarettes. Respondents considered e-cigarettes to be harmful and addictive

    E-papierosy w populacji studentów medycyny — częstość stosowania, postawy, motywacje

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    WSTĘP: Palenie papierosów elektronicznych (e-papierosów) stało się wyzwaniem dla zdrowia publicznego. Celem badania była ocena częstości stosowania e-papierosów oraz papierosów tradycyjnych, porównanie stylów palenia oraz ocena motywacji do palenia e-papierosów. MATERIAŁ I METODY: Studenci Wydziału Lekarskiego w Katowicach (Śląskiego Uniwersytetu Medycznego w Katowicach) — 1700 osób — zostali zaproszeni do udziału w przekrojowym badaniu kwestionariuszowym dotyczącym częstości palenia e-papierosów i papierosów tradycyjnych oraz opinii na ich temat. WYNIKI: Odpowiedzi uzyskano od 1318 studentów (odsetek odpowiedzi: 77,5%); średnia wieku: 22,1 ± 2,2 roku. Papierosy tradycyjne paliło 239 (18,1%) ankietowanych, a e-papierosy — 46 (3,5%) badanych. Pośród ankietowanych mężczyzn, e-papierosy paliło 4,9%, wśród kobiet odsetek ten wynosił 2,8% (p = 0,05). W porównaniu z palaczami papierosów tradycyjnych, palacze e-papierosów używali ich od krótszego czasu (p < 0,001), palili więcej razy w tygodniu (p = 0,01) oraz częściej w ciągu dnia (p < 0,001) niż palacze tradycyjnych papierosów. Palacze obu typów papierosów częściej palili papierosy tradycyjne niż elektroniczne (p = 0,01), ale e-papierosy palili częściej w ciągu dnia (p = 0,003). Wybór e-liquidu był uzależniony od smaku (50,0%), stężenia nikotyny (21,7%) oraz ceny (7,6%). E-papierosy bez zawartości nikotyny były używane przez 6,5% palaczy. Palacze obu typów papierosów częściej wybierali e-liquidy z wyższym stężeniem nikotyny (p = 0,01). Najczęstszymi motywacjami do rozpoczęcia palenia e-papierosów były: chęć rzucenia palenia papierosów tradycyjnych (58,7%), mniej szkodliwy wpływ na zdrowie (43,5%) oraz cena (34,8%). Palenie e-papierosów było postrzegane jako bezpieczne dla zdrowia przez 6,0% pytanych (35,5% e-palaczy i 4,9% niepalących e-papierosów; p < 0,001). WNIOSKI: Wśród studentów medycyny e-papieros jest mniej popularny niż tradycyjne papierosy. W badanej grupie e-papierosy uważane są za szkodliwe dla zdrowia i mogące uzależniać.WSTĘP: Palenie papierosów elektronicznych (e-papierosów) stało się wyzwaniem dla zdrowia publicznego. Celem badania była ocena częstości stosowania e-papierosów oraz papierosów tradycyjnych, porównanie stylów palenia oraz ocena motywacji do palenia e-papierosów. MATERIAŁ I METODY: Studenci Wydziału Lekarskiego w Katowicach (Śląskiego Uniwersytetu Medycznego w Katowicach) — 1700 osób — zostali zaproszeni do udziału w przekrojowym badaniu kwestionariuszowym dotyczącym częstości palenia e-papierosów i papierosów tradycyjnych oraz opinii na ich temat. WYNIKI: Odpowiedzi uzyskano od 1318 studentów (odsetek odpowiedzi: 77,5%); średnia wieku: 22,1 ± 2,2 roku. Papierosy tradycyjne paliło 239 (18,1%) ankietowanych, a e-papierosy — 46 (3,5%) badanych. Pośród ankietowanych mężczyzn, e-papierosy paliło 4,9%, wśród kobiet odsetek ten wynosił 2,8% (p = 0,05). W porównaniu z palaczami papierosów tradycyjnych, palacze e-papierosów używali ich od krótszego czasu (p < 0,001), palili więcej razy w tygodniu (p = 0,01) oraz częściej w ciągu dnia (p < 0,001) niż palacze tradycyjnych papierosów. Palacze obu typów papierosów częściej palili papierosy tradycyjne niż elektroniczne (p = 0,01), ale e-papierosy palili częściej w ciągu dnia (p = 0,003). Wybór e-liquidu był uzależniony od smaku (50,0%), stężenia nikotyny (21,7%) oraz ceny (7,6%). E-papierosy bez zawartości nikotyny były używane przez 6,5% palaczy. Palacze obu typów papierosów częściej wybierali e-liquidy z wyższym stężeniem nikotyny (p = 0,01). Najczęstszymi motywacjami do rozpoczęcia palenia e-papierosów były: chęć rzucenia palenia papierosów tradycyjnych (58,7%), mniej szkodliwy wpływ na zdrowie (43,5%) oraz cena (34,8%). Palenie e-papierosów było postrzegane jako bezpieczne dla zdrowia przez 6,0% pytanych (35,5% e-palaczy i 4,9% niepalących e-papierosów; p < 0,001). WNIOSKI: Wśród studentów medycyny e-papieros jest mniej popularny niż tradycyjne papierosy. W badanej grupie e-papierosy uważane są za szkodliwe dla zdrowia i mogące uzależniać

    Tick-Transmitted Diseases Caused by Apicomplexa

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    The objective of this study is to draw attention to Apicomplexa-caused diseases transmitted by ticks. We present ultimate and intermediate hosts of Apicomplexa, including man, as well as vectors transmitting these unicellular Protista. We describe symptoms of Apicomplexa-caused diseases and contemporary methods of diagnostics and therapy. It is noteworthy that the ticks and tick-transmitted pathogenes are distinctly increasing their distribution ranges. Besides, it is important that the ticks are adapted to use many different hosts, including birds, which increases the ticks’ expansion abilities

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of ttt\overline{t}, W+bbW+b\overline{b} and W+ccW+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays WνW\rightarrow\ell\nu, where \ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
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