251 research outputs found
Decentralized Coordination in Self-Organizing Systems based on Peer-to-Peer Coordination Spaces
Coordination is an important aspect to realize Self-organizing Systemsusually implemented as part of the functional properties of the system. This paper promotes a separation of concerns via a declarative approach to realize decentralized coordination in Self-organizing Multi-Agent Systems (MAS). In previous work the concept of Coordination Spaces was developed which provides explicit support for the task of coordination in MAS. Coordination Spaces are part of the agent environment and handle a declarative description of the coordination process. Thereby, this approach allows developers rather focusing on what to coordinate than on how to coordinate. Also by releasing the developer from programming coordination manually, the approach offers benefits like reusability and interoperability of coordination processes. This paper extends the approach by a distribution concept for coordination spaces. By using different techniques like remote service calls, group communicationand publish/subscribe models the distribution of information among multiple platforms in a peer-to-peer like approach is achieved
A Reputation-Based Approach to Self-Adaptive Service Selection
Service-orientation provides concepts and tools for flexible composition and management of largescale distributed software applications. The automated run-time management of such loosely coupled software systems, however, poses still major challenges and is therefore an active research area, including the use of novel computing paradigms. In this context, the dynamic and adaptive selection of best possible service providers is an important task, which can be addressed by an appropriate middleware layer that allows considering different service quality aspects when managing the adaptive execution of distributed service workflows dynamically. In such an approach, service consumers are enabled to delegate the adaptive selection of service providers at run-time to the execution infrastructure. The selection criteria used are based on the cost of a service provision and the continuous, dynamic evaluation of reputations of providers, i.e. maintained track records of meeting the respective service commitments. This paper discusses the design and operating principle of such an automatic service selection middleware extension. Its ability to balance different quality criteria for service selection, such as service cost vs. the reliability of provision, is empirically evaluated based on a multi-agent platform approach
Systematically Engineering Self-Organizing Systems: The SodekoVS Approach
Self-organizing systems promise new software quality attributes that
are very hard to obtain using standard software engineering approaches. In accordance
with the visions of e.g. autonomic computing and organic computing,
self-organizing systems promote self-adaptability as one major property helping to
realize software that can manage itself at runtime. In this respect, self-adaptability
can be seen as a necessary foundation for realizing e.g. self* properties such as self-configuration or self-protection. However, the systematic development of systems
exhibiting such properties challenges current development practices. The SodekoVS
project addresses the challenge to purposefully engineer adaptivity by proposing a
new approach that considers the system architecture as well as the software development
methodology as integral intertwined aspects for system construction. Following
the proposed process, self-organizing dynamics, inspired by biological, physical
and social systems, can be integrated into applications by composing modules
that distribute feedback control structures among system entities. These compositions
support hierarchical as well as completely decentralized solutions without a
single point of failure. This novel development conception is supported by a reference
architecture, a tailored programming model as well as a library of ready to use
self-organizing patterns. The key challenges, recent research activities, application
scenarios as well as intermediate results are discussed
Hereditary angioedema (HAE) in children and adolescents : a consensus on therapeutic strategies
Hereditary angioedema due to C1 inhibitor (C1 esterase inhibitor) deficiency (types I and II HAE-C1-INH) is a rare disease that usually presents during childhood or adolescence with intermittent episodes of potentially life-threatening angioedema. Diagnosis as early as possible is important to avoid ineffective therapies and to properly treat swelling attacks. At a consensus meeting in June 2011, pediatricians and dermatologists from Germany, Austria, and Switzerland reviewed the currently available literature, including published international consensus recommendations for HAE therapy across all age groups. Published recommendations cannot be unconditionally adopted for pediatric patients in German-speaking countries given the current approval status of HAE drugs. This article provides an overview and discusses drugs available for HAE therapy, their approval status, and study results obtained in adult and pediatric patients. Recommendations for developing appropriate treatment strategies in the management of HAE in pediatric patients in German-speaking countries are provided.Conclusion Currently, plasma-derived C1 inhibitor concentrate is considered the best available option for the treatment of acute HAE-C1-INH attacks in pediatric patients in German-speaking countries, as well as for short-term and long-term prophylaxis
Investigation of the molecular switching process between spin crossover states of triazole complexes as basis for optical sensing applications
With the advent of the first laser sources and suitable detectors, optical sensor applications immediately also came into focus. During the last decades, a huge variety of optical sensor concepts were developed, yet the forecast for the future application potential appears even larger. In this context, the development of new sensor probes at different scales down to the atomic or molecular level open new avenues for research and development. We investigated an iron based triazole molecular spin-crossover complex changing its absorption characteristics significantly by varying environmental parameters such as humidity, temperature, magnetic or electric field, respectively, with respect to its suitability for a new class of versatile molecular sensor probes. Hereby, besides the investigation of synthesized pure bulk material using different analyzing methods, we also studied amorphous micro particles which were applied in or onto optical waveguide structures. We found that significant changes of the reflection spectra can also be obtained after combining the particles with different types of optical waveguides.The obtained results demonstrate the suitability of the material complex for a broad field of future sensor applications
Reference Intervals for Platelet Counts in the Elderly: Results from the Prospective SENIORLAB Study.
Currently, age- and sex-independent reference limits (RLs) are frequently used to interpret platelet counts in seniors. We aimed to define and validate reference intervals (RIs) for platelet counts within the framework of the prospective SENIORLAB study. Subjectively healthy Swiss individuals aged 60 years and older were prospectively included and followed for morbidity and mortality. Participants who had circumstances known to affect platelet counts were excluded. The obtained RIs were validated with indirect statistical methods. Frequencies of abnormal platelet counts in a population-based setting, including 41.5% of the entire age-specific population of the Principality of Liechtenstein, were compared by using age- and sex-independent RIs and the RLs obtained in the present study. For males (n = 542), 95% RIs for platelet counts were defined as follows: 150-300 Ă— 109/L (60-69 years); 130-300 Ă— 109/L (70-79 years); and 120-300 Ă— 109/L (80 years and above). For females (n = 661), the consolidated age-independent 95% RI was 165-355 Ă— 109/L. These RI values were validated by indirect RI determination of 51,687 (30,392 female/21,295 male) patients of the same age. Age- and sex-independent RIs exhibited imbalanced frequencies of abnormal platelet counts between the two sexes, which were corrected by introducing age- and sex-specific RLs. In conclusion, females have higher platelet counts than males. Whereas the upper RL for males remains constant, the lower RL decreases with age. We propose to abandon the practice of employing sex- and age-independent RL for platelet counts in the elderly
Allergen-induced asthmatic responses modified by a GATA3-specific DNAzyme
BACKGROUND : The most prevalent phenotype of asthma is characterized by eosinophil-dominated inflammation that is driven by a type 2 helper T cell (Th2). Therapeutic targeting of GATA3, an important transcription factor of the Th2 pathway, may be beneficial. We evaluated the safety and efficacy of SB010, a novel DNA enzyme (DNAzyme) that is able to cleave and inactivate GATA3 messenger RNA (mRNA).
METHODS : We conducted a randomized, double-blind, placebo-controlled, multicenter clinical trial of SB010 involving patients who had allergic asthma with sputum eosinophilia and who also had biphasic early and late asthmatic responses after laboratory-based allergen provocation. A total of 40 patients could be evaluated; 21 were assigned to receive 10 mg of SB010, and 19 were assigned to receive placebo, with each study drug administered by means of inhalation once daily for 28 days. An allergen challenge was performed before and after the 28-day period. The primary end point was the late asthmatic response as quantified by the change in the area under the curve (AUC) for forced expiratory volume in 1 second (FEV1).
RESULTS : After 28 days, SB010 attenuated the mean late asthmatic response by 34%, as compared with the baseline response, according to the AUC for FEV1, whereas placebo was associated with a 1% increase in the AUC for FEV1 (P = 0.02). The early asthmatic response with SB010 was attenuated by 11% as measured by the AUC for FEV1, whereas the early response with placebo was increased by 10% (P = 0.03). Inhibition of the late asthmatic response by SB010 was associated with attenuation of allergen-induced sputum eosinophilia and with lower levels of tryptase in sputum and lower plasma levels of interleukin-5. Allergen-induced levels of fractional exhaled nitric oxide and airway hyperresponsiveness to methacholine were not affected by either SB010 or placebo.
CONCLUSIONS : Treatment with SB010 significantly attenuated both late and early asthmatic responses after allergen provocation in patients with allergic asthma. Biomarker analysis showed an attenuation of Th2-regulated inflammatory responses
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