Coherent photon-photon interactions in very peripheral relativistic heavy ion collisions

Heavy ions at high velocities provide very strong electromagnetic fields for a very short time. The main characteristics of ultraperipheral relativistic heavy ion collisions are reviewed, characteristic parameters are identified. The main interest in ultraperipheral heavy ion collisions at relativistic ion colliders like the LHC is the interactions of very high energy (equivalent) photons with the countermoving (equivalent) photons and hadrons (protons/ions). The physics of these interactions is quite different from and complementary to the physics of the strong fields achieved with current and future lasers.Comment: 5 pages, 5 figures, invited talk presented at the ELI Workshop and School on Fundamental Physics with Ultra-high Fields (September 29- October 2, 2008, Frauenwoerth, German

Highly specific reasons for nonadherence to antiretroviral therapy: results from the German adherence study

Johanna Boretzki,1,2 Eva Wolf,3 Carmen Wiese,4 Sebastian Noe,4 Annamaria Balogh,3 Anja Meurer,5 Ivanka Krznaric,6 Alexander Zink,7 Christian Lersch,1 Christoph D Spinner1,2 1Department of Medicine II, University Hospital Klinikum rechts der Isar, Munich, 2German Center for Infection Research, Partner Site Munich, 3MUC Research, Munich, 4MVZ Karlsplatz, HIV Clinical Care Center, Munich, 5Center for Infectiology and Internal Medicine, Munich, 6Center for Infectiology Prenzlauer Berg, Berlin, 7Department of Dermatology and Allergology, University Hospital Klinikum rechts der Isar, Munich, Germany Background: Reasons for and frequency of nonadherence to antiretroviral therapy (ART) may have changed due to pharmacological improvements. In addition, the importance of known non-pharmacologic reasons for nonadherence is unclear.Methods: We performed a cross-sectional, noninterventional, multicenter study to identify current reasons for nonadherence. Patients were categorized by physicians into the following adherence groups: good, unstable, or poor adherence. Co-variables of interest included age, sex, time since HIV diagnosis, ART duration, current ART regimen, HIV transmission route, comorbidity, HIV-1 RNA viral load (VL), and CD4 cell count. Patients self-reported the number of missed doses and provided their specific reasons for nonadherent behavior. Statistical analyses were performed using Fisher’s extended exact test, Kruskal–Wallis test, and logistic regression models.Results: Our study assessed 215 participants with good (n=162), unstable (n=36), and poor adherence (n=17). Compared to patients with good adherence, patients with unstable and poor adherence reported more often to have missed at least one dose during the last week (good 11% vs unstable 47% vs poor 63%, p<0.001). Physicians’ adherence assessment was concordant with patients’ self-reports of missed doses during the last week (no vs one or more) in 81% cases. Similarly, we found a strong association of physicians’ assessment with viral suppression. Logistic regression analysis showed that “reduced adherence” – defined as unstable or poor – was significantly associated with patients <30 years old, intravenous drug use, history of acquired immune deficiency syndrome (AIDS), and psychiatric disorders (p<0.05). Univariate analyses showed that specific reasons, such as questioning the efficacy/dosing of ART, HIV stigma, interactive toxicity beliefs regarding alcohol and/or party drugs, and dissatisfaction with regimen complexity, correlated with unstable or poor adherence (p<0.05).Conclusion: Identification of factors associated with poor adherence helps in identifying patients with a higher risk for nonadherence. Reasons for nonadherence should be directly addressed in every patient, because they are common and constitute possible adherence intervention points. Keywords: human immunodeficiency virus, HIV, antiretroviral therapy, ART, adherence, nonadherence, patients’ belief

Entwicklung eines 'Hoerbildverfahrens' zur praxisgerechten Ueberpruefung und Optimierung von Hoergeraeten mit alltagsnahen Hoersituationen Abschlussbericht

The 'Hoerbildverfahren' was developed to supplement the diagnostic procedures of frequency specific speech audiometry and audible field audiometry. It is used to evaluate and optimize hearing rehabilitation. The new procedure is based on stereophonic recordings of everyday hearing situations. The adequate transmission of their physical and psychophysical characteristics by the hearing aid is central to the success of the fitting. Based on these recordings hearing dimensions (e.g. sharpness, reverberation, overall quality) were determined which allow the reliable evaluation of the transmission quality. In addition, a presentation and scaling method were developed which can be used for the fitting of hearing aids. The procedure also allows the judgement of global speech intelligibility for everyday dialogues with background noise of varying loudness and the effort required to understand speech. A first evaluation of the procedure tool place in a field study with three acousticians and 25 subjects. The subjects suffered from sensorineural hearing loss (30-50 dB HL below 1 kHz, high freqency slope to a maximum of 70 dB HL at 4 kHz). We were able to show that the initial fitting of the hearing aid on the basis of the audible field audiometry resulted in good transmission quality which was enhanced by the fine tuning using the 'Hoerbildverfahren'. Furthermore, the fine tuning increased speech intelligibility in moderate background noise (car interior noise) and reduced the effort required for understanding speech. (orig.)SIGLEAvailable from TIB Hannover: F97B2257+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman