Vergleich dreier Ringversuche zur radioimmunologischen Thyrotropin-Bestimmung nach dem "Münchner Modell"

Peer Reviewe

Integrated mobility and resource management for cross-network resource sharing in heterogeneous wireless networks using traffic offload policies

The problem of efficient use of resources in wireless access networks becomes critical today with users expecting continuous high-speed network access. While access network capacity continues to increase, simultaneous operation of multiple wireless access networks presents an opportunity to increase the data rates available to end-users even further using intelligent cross-network resource sharing. This paper introduces a new integrated mobility and resource management (IMRM) framework for automatic execution of policies for cross-network resource sharing using traffic offload and pre-emptive resource reservation algorithms. The presented framework enables both mobile-initiated and network-initiated resource sharing policies to be executed. This paper presents the framework in detail and analyses its performance using extensive ns-2 simulations of the operation of a set of static policies based on measured signal strength, and dynamic pre-emptive network-initiated policies in a WiFi/WiMAX scenario. The detailed evaluation of the static policies clearly shows that the quality of voice applications shows large deviation, mostly due to very different levels of delay in access networks. Based on these conclusions, this paper presents a design of two new dynamic policies and shows that such policies, when efficiently implemented using the new IMRM framework can greatly improve the capacity of the network to serve voice traffic with a minimal impact on the data traffic and with a very low signalling overhead

Scheduling Algorithm for Coordinated Beamforming in Heterogeneous Macro/Pico LTE-Advanced Networks

Pico base stations are an important instrument to increase the capacity of mobile radio networks. Due to the limited spectrum availability it will be necessary to operate macro and pico base stations on the same frequency bands. In this case the transmit power imbalance between different base station types creates new interference situations. Coordinated beamforming is one method of base station cooperation that can be applied to mitigate interference in this scenario. The work presented here describes a scheduler for coordinated beamforming in an LTE-Advanced system which relies on sharing only the feedback information from the mobile stations between the base stations. System level simulation results show that this approach can decrease the interference experienced by the mobile stations attached to the pico base stations

Methodische Untersuchungen und Vergleich von 7 kommerziellen Kits zur radioimmunologischen Thyrotropin-Bestimmung aus dem getrockneten Blutstopfen

Peer Reviewe

1D numerical and experimental investigations of an ultralean pre-chamber engine

In recent years, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations. With this solution, in fact, it is possible to simultaneously reduce NOx raw emissions and fuel consumption due to decreased heat losses, higher thermodynamic efficiency, and enhanced knock resistance. However, the real applicability of this technique is strongly limited by the increase in cyclic variation and the occurrence of misfire, which are typical for the combustion of homogeneous lean air/fuel mixtures. The employment of a Pre-Chamber (PC), in which the combustion begins before proceeding in the main combustion chamber, has already shown the capability of significantly extending the lean-burn limit. In this work, the potential of an ultralean PC SI engine for a decisive improvement of the thermal efficiency is presented by means of numerical and experimental analyses. The SI engine is experimentally investigated with and without the employment of the PC with the aim to analyze the real gain of this innovative combustion system. For both configurations, the engine is tested at various speeds, loads, and air-fuel ratios. A commercial gasoline fuel is directly injected into the Main Chamber (MC), while the PC is fed in a passive or active mode. Compressed Natural Gas (CNG) or Hydrogen (H2) is used in the actual case. A 1D model of the engine under study is implemented in a commercial modeling framework and is integrated with “in-house developed” sub-models for the simulation of the combustion and turbulence phenomena occurring in this unconventional engine. The numerical approach proves to reproduce the experimental data with good accuracy, without requiring any case-dependent tuning of the model constants. Both the numerical and experimental results show an improvement of the indicated thermal efficiency of the active PC, compared to the conventional ignition device, especially at high loads and low speeds. The injection of H2 into the PC leads to a significant benefit only with very lean mixtures. With the passive fueling of the PC, the lean-burn limit is less extended, with the consequent lower improvement potential for thermal efficiency

How to Reach the Hidden: Strategies for Recruiting HIV-Positive Transgender Women

Purpose: Transgender women (TGW) or biological men, who identify as women, are at high risk for HIV infection and are less likely to enter care. TGW are among the most marginalized of all sexual and gender minority populations, and are therefore at greater risk of violence and discrimination. Further, HIV remains one of the most stigmatizing illnesses in the US and disclosure of one’s HIV status could lead to negative health and social outcomes. Due to social marginalization and stigma related to their gender identity and HIV status, this population is often hard to reach and is underrepresented in healthcare utilization research. Theoretical/conceptual framework: The Network Episode Model is a service utilization model that has been used for exploring the patterns and pathways through which hard to reach populations access care for medical problems and was used to inform this study. Sample: Twenty to twenty-five HIV-positive TGW who accessed care at least once within one year prior to the start of the study. Method and results: Prior to data collection the researcher embedded herself in the community by networking and consulting with community gatekeepers, attending cultural celebrations and events, and volunteering at community agencies that served the transgender population. Using purposive and snowball sampling strategies, participants were then recruited from community- based agencies that serve TGW and from venues where TGW were known to socialize. Local and state health departments assisted with recruitment by identifying eligible participants through care coordination and HIV services databases and direct mailings of recruitment fliers. To protect against the loss of confidentiality, private one-on-one interviews were conducted, a waiver of written informed consent was obtained, and aliases were used to collect and report results. These strategies were selected because they have the highest success rate of recruiting hard to reach populations, provided the greatest protection against loss of privacy, and build on network ties through which TGW socialize and seek formal and informal care. Conclusions: Outcomes of these recruitment strategies and lessons learned in recruiting members of this highly marginalized group will be discussed