Chiral symmetry and strangeness at SIS energies

In this talk we review the consequences of the chiral SU(3) symmetry for strangeness propagation in nuclear matter. Objects of crucial importance are the meson-baryon scattering amplitudes obtained within the chiral coupled-channel effective field theory. Results for antikaon and hyperon-resonance spectral functions in cold nuclear matter are presented and discussed. The importance of the Sigma(1385) resonance for the subthreshold antikaon production in heavy-ion reaction at SIS is pointed out. The in-medium properties of the latter together with an antikaon spectral function based on chiral SU(3) dynamics suggest a significant enhancement of the pi \Lambda -> bar K N reaction in nuclear matter.Comment: 10 pages, 2 figures, invited talk at Erice 200

Development of Prophylactic HPV Vaccines

Since several years it has been accepted that persistent infection with certain (so called-high risk: HR) types of Human papillomaviruses (HPV) represents a strong risk factor for cervical cancer. The most frequent HR HPV types 16 and 18 account for about 70% of this tumour, which is the second most frequent malignancy in women worldwide. Several studies in animal papillomavirus models revealed that protection against infection is conferred by neutralizing antibodies directed against conformational epitopes of the major structural protein L1. Such antibodies can most efficiently be induced by immunization with virus-like particles (VLP) that assemble spontaneously following expression of L1 in recombinant vectors. Large-scale production of HPV 16 and 18 VLPs proved to be successful facilitating, a few years ago, first clinical trials on safety and immunogenicity. In the meantime more than 25,000 women have been included into several efficacy trials which demonstrated protection against persistent infection with HPV 16 and 18 and against the development of precursor lesions to cervical cancer. Although the ultimate proof of success, i.e. reduction of cancer incidence still requires the immunization of large populations and many years of follow-up, the existing data are so persuasive that the responsible agencies in several countries permitted the licensing of the first HPV vaccine in 2006. Several questions such as the duration of protection, the need development of for post-exposure vaccination strategies and availability of such vaccine in low-budget countries are open and will be discussed

Age-related impairment of human T lymphocytes' activation: specific differences between CD4+ and CD8+ subsets

The relevance of physiological immune aging is of great interest with respect to determining disorders with pathologic immune function in aging individuals. In recent years, the relevance of changes in peripheral lymphocytes in age-associated neurologic diseases has become more evident. Due to the lack of immunological studies, covering more than one event after mitogenic activation, we envisaged a new concept in the present study, aiming to investigate several events, starting from T cell receptor (TCR) ligation up to T cell proliferation. In addition, we addressed the question whether changes are present in the subsets (CD4, CD8) with aging. Phosphorylation of tyrosine residues declines with increasing age in CD4+ cells. Fewer levels of CD69 positive cells after 4 h mitogenic activation, altered expression of cytokines (IL2, IFN-gamma and TNF-alpha; 22 h) and lower proliferation (72 h) were determined in aging. Moreover, it could be shown that CD8+ lymphocytes react more effectively to mitogenic stimulation with reference to CD69 expression and proliferation in both age groups (60 years old). These data indicate that T cell activation, mediated by TCR engagement, is significantly impaired in aging and both subsets are affected. However, bypassing the TCR does not fully restore T cell function, indicating that there are more mechanisms involved than impaired signal transduction through TCR only. The results will be discussed in relation to their relevance in neurodegenerative and psychiatric disorders

Quasi-deterministic transport of Brownian particles in an oscillating periodic potential

We consider overdamped Brownian dynamics in a periodic potential with temporally oscillating amplitude. We analyze the transport which shows effective diffusion enhanced by the oscillations and derive approximate expressions for the diffusion coefficient. Furthermore we analyze the effect of the oscillating potential on the transport if additionally a constant force is applied. We show the existence of synchronization regimes at which the deterministic dynamics is in resonance with the potential oscillations giving rise to transport with extremely low dispersion. We distinguish slow and fast oscillatory driving and give analytical expressions for the mean velocity and effective diffusion.Comment: submitted: Feb 12th, 201

Sistemas de propulsión de aplicación optimizada para operación energéticamente eficiente

Today, optimal propellers are designed by using advanced numerical methods. Major revolutionary improvements cannot be expected. More essential are the design conditions and the optimal adaptation of the propulsion system according to the operational requirements. The selection and optimisation of the propulsion system based on a systematic analysis of the ship’s requirements and the operation profile are the prerequisites for reliable and energy-efficient propulsion. Solutions are presented, which accommodate these issues with a focus on steerable rudderpropellers. Considerations include the efficiency potential of the propulsor itself, optimisation of the engine propeller interaction, and optimisation of a demandresponsive energy supply. The propeller-thruster interaction is complex, but offers some potential for optimisation. Results of examinations show this. The power distribution between multiple propellers at high loads of limited propeller diameters increases the efficiency. This can be done by double-propeller systems like the SCHOTTEL TwinPropeller or by distributing the power on several thrusters. This distributed propulsion offers economic operation and an increased lifetime by means of the demandresponsive use of energy. An efficiency-optimized electric motor instead of the upper gear box reduces the mechanical losses in the case of diesel-electric propulsion. An example: the SCHOTTEL CombiDrive.En la actualidad, las hélices óptimas son diseñadas mediante el uso de métodos numéricos avanzados. No se pueden esperar grandes mejoras revolucionarias. Más esenciales son las condiciones de diseño y la adaptación óptima del sistema de propulsión de acuerdo a los requerimientos operacionales. La selección y optimización del sistema de propulsión basado en un análisis sistémico de los requerimientos del buque y el perfil de operación son los prerrequisitos para propulsión confiable y energéticamente eficiente. Se presentan soluciones, que acomodan estos asuntos con un enfoque sobre hélices de timón dirigibles (steerable rudderpropellers). Las consideraciones incluyen el potencial de eficiencia del propulsor en sí, la optimización de la interacción entre la hélice y el motor y la optimización de un suministro de energía que responda a la demanda. La interacción de hélice y el propulsor es compleja, pero ofrece algún potencial para optimización; los resultados de las pruebas lo demuestran. La distribución de potencia entre múltiples hélices con altas cargas de diámetros de hélice limitados aumenta la eficiencia. Esto se puede lograr por sistemas de doble hélice como el Doble Hélice de SCHOTTEL o mediante la distribución de potencia en varios propulsores. Esta propulsión distribuida ofrece operación económica y ampliación de vida útil mediante el uso de energía que responda a la demanda. Un motor eléctrico de eficiencia óptima, en vez de la caja de engranajes superior reduce las pérdidas mecánicas en el caso de propulsión diesel-eléctrica. Un ejemplo: El SCHOTTEL CombiDrive

The interleukin-6 -174promoter polymorphism is associated with long-term kidney allograft survival

The interleukin-6 -174promoter polymorphism is associated with long-term kidney allograft survival.BackgroundTh1-dependent effector mechanisms may be responsible for allograft rejection. Recently, interleukin-6 (IL-6) has been shown to antagonize CD4+ T cells to effector Th2 cells and, in the process, differentiate them into Th1 cells.MethodsTo assess the role of IL-6 in long-term allograft survival, 158 patients after first cadaveric kidney transplantation were analyzed for the biallelic –174G→C promoter polymorphism of the IL-6 gene.ResultsCarriers of the –174C-allele (genotype GC/CC) had an inferior three-year graft survival (71/104 = 68.3%; P = 0.0059) with a 3.7-fold increased relative risk of graft loss compared to carriers of the –174GG-genotype (48/54 = 88.9%). The –174GC/CC-genotype retained its negative impact on graft survival when other established prognostic factors and further cytokine polymorphisms (-308TNF-α, TGF-β1 codon 10 & 25, -592/-819/-1082IL-10 and +874IFN-γ) were considered simultaneously.ConclusionsSince the clinical impact on transplant outcome seems as important as matching for histocompatibility antigens, genotyping of the IL-6 -174polymorphism may offer a new method for identifying patients at increased risk of allograft loss