Extraction of information about periodic orbits from scattering functions

As a contribution to the inverse scattering problem for classical chaotic systems, we show that one can select sequences of intervals of continuity, each of which yields the information about period, eigenvalue and symmetry of one unstable periodic orbit.Comment: LaTeX, 13 pages (includes 5 eps-figures

Determinants of the acute phase protein CRP in myocardial infarction survivors

Background: C-reactive protein (CRP), a sensitive marker of the acute phase response, has been associated with future cardiovascular endpoints independent of other risk factors such as body mass index (BMI), age and cholesterol levels. Risk assessment in populations at risk of cardiovascular disease is usually based on one or two measurements. Variation of CRP among certain subgroups of the population, however, has not been examined in detail. The purpose of this thesis is to study associations between time-invariant patient characteristics and mean high sensitivity (hs)-CRP concentrations and parameters that influence the variation of hs-CRP in a joint analysis. Additionally, associations between parameters that might impact hs-CRP in the 24 hours before the blood draw, such as environmental tobacco smoke exposure, alcohol consumption or extreme stress or anger, were examined. Moreover, the short-term impact of ambient air pollution on hs-CRP was studied. Methods: This thesis is based on AIRGENE, a multi centre study conducted in six European cities. Hs-CRP was measured repeatedly up to eight times every four to six weeks in 1,003 myocardial infarction (MI) survivors. At the first visit data on health status, medication intake and smoking history were collected by questionnaire. Blood pressure and BMI were measured and a blood serum sample was drawn. An additional blood sample was drawn at each visit for the determination of hs-CRP and data on life-style in the 24 hours before the visit were collected. In each city, hourly data on particle number concentrations, mass concentrations of particulate matter (PM) <10μm (PM10) and <2.5μm (PM2.5), gaseous pollutants and meteorological data were collected at central monitoring sites. Results: BMI was one of the strongest determinants with higher geometric mean hs-CRP concentrations in overweight and obese patients. Regarding age, a U-shaped relationship with the lowest hs-CRP level in the group of 50 to 59 year olds was found. Variation of hs-CRP within patients was only slightly lower than between patients. Patients who reported the presence of angina pectoris, emphysema and congestive heart failure showed a lower variation (-11.0, -24.9 and -41.6% variation, respectively) while the geometric mean concentration seemed not to be affected. For patients with baseline glycosylised haemoglobin (HbA1c) levels of 6.5% and above, on the other hand, our data revealed higher hs-CRP (geometric mean: 26.2, confidence interval: 7.2; 48.6) and a higher variation (20.7% variation, p-value 0.0034). Results were similar, although not as pronounced, for the diagnosis of type 2 diabetes. Variation was also higher in males compared to females and smokers compared to non-smokers (24.8 and 27.3%, respectively) with a lower geometric mean concentration in males and a higher one in smokers. Patients reporting the intake of statins or other lipid-lowering drugs showed significantly lower hs-CRP and also less variation. Patients using angiotensine converting enzyme (ACE)-inhibitors on the other hand, a higher variation was found while geometric mean concentrations seemed not to be associated with medication intake. Life-style parameters in the 24 hours preceding blood draw did not have a major impact on hs-CRP. No association was seen between ambient air pollutants and hs-CRP concentrations. Conclusion: This work confirms and extends published results on the association between patient characteristics and intake of medication and hs-CRP concentrations in a panel of male and female MI survivors. The higher variation found in males, smokers and subjects with elevated HbA1c concentrations indicates that basing preventive medical measures on a single measurement of hs-CRP might not be sufficient. It is conceivable that individuals with a generally higher level of inflammatory markers, and/or a higher variation, for example patients with diabetes, might react more strongly to environmental factors such as air pollution. The lack of association between air pollution and hs-CRP in these data is possibly due to a widespread intake of statins in this population of MI survivors

Mikrobiologisches Monitoring von Milchprodukten mit verlängerter Haltbarkeit

Milch und Milchprodukte mit verlängerter Haltbarkeit gewinnen Dank des frischmilchähnlichen Geschmacks, erzielt durch neue Verfahren zur schonenden Produktbehandlung und dem gleichzeitigen Vorteil der verlängerten Haltbarkeit durch nahezu Elimination in der Rohmilch vorhandener Verderbskeime, immer mehr an Bedeutung auf dem europäischen Markt. Im Rahmen dieser Arbeit wurden mikrobiolgische Schnellmethoden auf ihre Eignung zur mikrobiolgischen Qualitätssicherung im Molkereibetrieb evaluiert. Die eingesetzten Schnellmethoden – CellScan InnovateÔ System, BacT/ALERTâ 3D, MicroFossÔ 32 System beruhen auf der Erfassung von Stoffwechselprodukten von Mikroorganismen und wurden mit routinemässig angewandten Koloniezählverfahren hinsichtlich Praxistauglichkeit mit besonderem Fokus auf ihre Empfindlichkeit, Möglichkeiten und Grenzen, Eignung zur Haltbarkeitsvorhersage, Antwortzeit, Kosten und Arbeitsaufwand verglichen. Die Proben wurden mit zuvor isolierten und spezifizierten Mikroorganismen kontaminiert und in unterschiedlichen Konzentrationsstufen beimpft. Die Entwicklung der Keimzahl wurde in Mehrfachbestimmungen sowie über eine Lagerdauer von zwei Wochen mit den Schnellmethoden und der Referenzmethode erfasst. Mittels ATP-Messung kann ein schneller Hygienestatus ermittelt werden. Allerdings ist dafür eine Inkubation der Milchprobe bei Raumtemperatur erforderlich. BacT/ALERT und MicroFoss kommen ohne Vorinkubation aus und liefern, abhängig von der vorliegenden Keimflora und Konzentration innerhalb weniger Stunden ein Ergebnis. Hinsichtlich der praktischen Benutzbarkeit zeichnen sich die Schnellmethoden bei vorhandenen Anschaffungskosten durch einen geringeren Arbeits-, Material- und Medienbedarf sowie durch eine hohe Sensitivität und Genauigkeit im Vergleich mit der Referenzmethode aus

Air temperature and inflammatory and coagulation responses in men with coronary or pulmonary disease during the winter season

Background and Objective Air temperature changes are associated with increased cardiovascular and respiratory risk, but the roles of inflammatory and coagulation markers are not well understood. We investigated the associations between temperature and several blood markers in patients with coronary heart disease (CHD) and pulmonary disease (PD). Methods Two studies were conducted in Erfurt, Germany, over two successive winters. 578 and 381 repeated blood measurements were collected from 57 CHD and 38 PD patients, respectively. Data on patient characteristics and disease history were gathered at baseline. Meteorological data were collected from existing networks. Associations were analysed using additive mixed models with random patient effects. Effect modification by diabetes status was investigated only in CHD patients, as only two PD patients had diabetes. Results Mean daily air temperature varied between -13 degrees C and 16 degrees C in both study periods. A 10 degrees C decrease in the 5-day temperature average before blood withdrawal led to an increase in platelet counts (% change from the mean: 3.0%, 95% CI 0.6% to 5.5%) and fibrinogen (5.5%, 1.3% to 9.7%), no change in C-reactive protein in PD patients, and a decrease in C-reactive protein in CHD patients. A 2-day delayed increase in factor VII associated with temperature decrease was seen in CHD patients (4.9%; 0.7% to 9.2%), while PD patients showed no effect. `Effects in CHD patients without diabetes' into `Effects on factor VII in CHD patients without diabetes'. Conclusions This study suggests that temperature decrease is associated with change in several blood parameters. The complex interplay of blood markers at low temperature may contribute to the observed association between cold and cardiovascular mortality and morbidity

Energy-level alignment at interfaces between manganese phthalocyanine and C60

We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc) and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs) is rather small

Methoden zur Bewertung der Exposition durch gepulste Magnetfelder im Niederfrequenzbereich

Zum Schutz der Bevölkerung und insbesondere von Arbeitnehmern existieren national und international Grenzwerte und Richtlinien hinsichtlich der Exposition durch niederfrequente Felder. Während über die Bewertung der Exposition durch Felder mit sinusförmigem Zeitverlauf weitgehend Einigkeit besteht, gibt es bei der Bewertung von breitbandigen und gepulsten Feldern verschiedene Ansätze. Einerseits werden Summenformeln angewendet, mit denen ein Bezug der Exposition auf den zulässigen Wert für jede einzelne Frequenzkomponente hergestellt wird. Dieses Vorgehen bietet sich an, wenn die Darstellung der zulässigen Werte (Auslöseschwellen) über der Frequenz als Amplitudenfrequenzgang interpretiert wird. Dementsprechend wird in den Richtlinien der ICNIRP [1] und in der Richtlinie 2013/35/EU [2] die Methode der gewichteten Spitzenwerte vorgeschlagen. Im Gegensatz dazu wird bei der Bewertung im Zeitbereich die Änderung der magnetischen Flussdichte aus dem Zeitverlauf bestimmt und mit einer zulässigen zeitlichen Änderung verglichen. In der BGV B11 [3] und im Forschungsbericht [4] wurden Bewertungsverfahren beschrieben, welche auf diesem Ansatz beruhen. In der Richtlinie [2] wurden keine genaueren Angaben zur Umsetzung der Methode der gewichteten Spitzenwerte gemacht. Zudem wird explizit darauf hingewiesen, dass auch andere wissenschaftlich nachgewiesene und validierte Expositionsberechnungsverfahren herangezogen werden können, vorausgesetzt diese führen zu annähernd gleichwertigen und vergleichbaren Ergebnissen. Mit dem vorliegenden Beitrag sollen deshalb die o.g. Verfahren anhand eines Beispiels miteinander verglichen werden

Classical Scattering for a driven inverted Gaussian potential in terms of the chaotic invariant set

We study the classical electron scattering from a driven inverted Gaussian potential, an open system, in terms of its chaotic invariant set. This chaotic invariant set is described by a ternary horseshoe construction on an appropriate Poincare surface of section. We find the development parameters that describe the hyperbolic component of the chaotic invariant set. In addition, we show that the hierarchical structure of the fractal set of singularities of the scattering functions is the same as the structure of the chaotic invariant set. Finally, we construct a symbolic encoding of the hierarchical structure of the set of singularities of the scattering functions and use concepts from the thermodynamical formalism to obtain one of the measures of chaos of the fractal set of singularities, the topological entropy.Comment: accepted in Phy. Rev.

Quantum and classical echoes in scattering systems described by simple Smale horseshoes

We explore the quantum scattering of systems classically described by binary and other low order Smale horseshoes, in a stage of development where the stable island associated with the inner periodic orbit is large, but chaos around this island is well developed. For short incoming pulses we find periodic echoes modulating an exponential decay over many periods. The period is directly related to the development stage of the horseshoe. We exemplify our studies with a one-dimensional system periodically kicked in time and we mention possible experiments.Comment: 7 pages with 6 reduced quality figures! Please contact the authors ([email protected]) for an original good quality pre-prin

Ultrafine particles and platelet activation in patients with coronary heart disease – results from a prospective panel study

BACKGROUND: Epidemiological studies on health effects of air pollution have consistently shown adverse cardiovascular effects. Toxicological studies have provided evidence for thrombogenic effects of particles. A prospective panel study in a susceptible population was conducted in Erfurt, Germany, to study the effects of daily changes in ambient particles on various blood cells and soluble CD40ligand (sCD40L, also known as CD154), a marker for platelet activation that can cause increased coagulation and inflammation. Blood cells and plasma sCD40L levels were repeatedly measured in 57 male patients with coronary heart disease (CHD) during winter 2000/2001. Fixed effects linear regression models were applied, adjusting for trend, weekday and meteorological parameters. Hourly data on ultrafine particles (UFP, number concentration of particles from 0.01 to 0.1 μm), mass concentration of particles less than 10 and 2.5 μm in diameter (PM(10), PM(2.5)), accumulation mode particle counts (AP, 0.1–1.0 μm), elemental and organic carbon, gaseous pollutants and meteorological data were collected at central monitoring sites. RESULTS: An immediate increase in plasma sCD40L was found in association with UFP and AP (% change from geometric mean: 7.1; CI: [0.1, 14.5] and 6.9; CI: [0.5, 13.8], respectively). Platelet counts decreased in association with UFP showing an immediate, a three days delayed (lag 3) and a 5-day average response (% change from the mean: -1.8; CI: [-3.4,-0.2]; -2.4; CI: [-4.5,-0.3] and -2.2; CI: [-4.0,-0.3] respectively). CONCLUSION: The increased plasma sCD40L levels support the hypothesis that higher levels of ambient air pollution lead to an inflammatory response in patients with CHD thus providing a possible explanation for the observed association between air pollution and cardiovascular morbidity and mortality in susceptible parts of the population