Performance Analysis of Unsupervised LTE Device-to-Device (D2D) Communication

Cellular network technology based device-to-device communication attracts increasing attention for use cases such as the control of autonomous vehicles on the ground and in the air. LTE provides device-to-device communication options, however, the configuration options are manifold (leading to 150+ possible combinations) and therefore the ideal combination of parameters is hard to find. Depending on the use case, either throughput, reliability or latency constraints may be the primary concern of the service provider. In this work we analyze the impact of different configuration settings of unsupervised LTE device-to-device (sidelink) communication on the system performance. Using a simulative approach we vary the length of the PSCCH period and the number of PSCCH subframes and determine the impact of different combinations of those parameters on the resulting latency, reliability and the interarrival times of the received packets. Furthermore we examine the system limitations by a scalability analysis. In this context, we propose a modified HARQ process to mitigate scalability constraints. Our results show that the proposed reduced HARQ retransmission probability can increase the system performance regarding latency and interarrival times as well as the packet transmission reliability for higher channel utilization

Notfalldiagnostik und Akutversorgung der Anaphylaxie

Anaphylaxis is a potentially life-threatening condition with increasing epidemiological and medical significance. This makes anaphylaxis relevant for emergency medicine. The objective of this study was to examine the treatment of anaphylaxis in various structures of emergency care in Germany and to determine possible diagnostic markers for detecting a severe allergic reaction with an unspecific clinical manifestation. The anaphylaxis cases treated by emergency physicians in Berlin between 2010 and 2011 were determined prospectively based on a survey. As a comparison, data from the ADAC air rescue service about the treatment of anaphylaxis in the period of 2010-2011 were analyzed. In addition, data from the anaphylaxis register, which primarily includes emergency treatment in practices and clinics, were examined. Aside from the registration of cases treated, in some emergency care centers in Berlin, blood samples were taken during the acute phase. Different biomarkers (tryptase, histamine, leukotrienes, and prostaglandin) were measured and checked in a second blood sample of the patients during a symptom-free interval. The basic epidemiological data were comparable in the different groups. Drugs were found to be the most common triggers of the cases registered and treated by emergency physicians for all levels of severity. When only the higher levels of severity were viewed, the triggers were inhomogeneous, with food being the leading cause. With respect to treatment data, it was found that adrenalin was used by emergency physicians more often than for acute treatment in outpatient clinics. Overall, adrenalin is not yet administered according to the recommendations of the national and international guidelines. Of the mediators in blood that were examined, prostaglandin D2 had the highest sensitivity and specificity. Further studies with larger cohorts are needed to establish prostaglandin D2 as a diagnostic marker. The studies showed that the acute treatment of anaphylaxis in Germany still does not follow the guidelines and there is need for improvement, especially regarding the intramuscular administration of adrenalin. Using safe and easily administered diagnostic tools such as point- of-care testing with prostaglandin D2, the implementation of guideline-based treatment of anaphylactic emergencies could be improved.Die Anaphylaxie ist ein potentiell lebensbedrohliches Krankheitsbild mit wachsender epidemiologischer und medizinischer Bedeutung. Die notfallmedizinische Beachtung der Anaphylaxie ist daher relevant. Ziel der Arbeit war die Erfassung der Anaphylaxiebehandlung in unterschiedlichen Strukturen der Notfallversorgung in Deutschland und die Bestimmung möglicher diagnostischer Marker zur Erfassung einer schweren allergischen Reaktion bei unspezifischer klinischer Manifestation. Hierzu wurden die notärztlich behandelten Anaphylaxiefälle in Berlin für den Zeitraum 2010 bis 2011 prospektiv anhand eines Fragebogens ermittelt. Vergleichend wurden retrospektiv für den Zeitraum 2010-2011 Daten der ADAC Luftrettung zur Behandlung der Anaphylaxie ausgewertet. Ergänzend wurden Angaben aus dem Anaphylaxieregister, die die Notfallbehandlungen in den Arztpraxen und Kliniken vornehmlich widerspiegeln, untersucht. Zusätzlich konnten in ausgewählten Notaufnahmen Berlins neben der Erfassung der Behandlungsfälle Blutabnahmen im Akutstadium erfolgen. Es wurden verschiedene Biomarker ( Tryptase, Histamin, Leukotriene, Prostaglandin ) bestimmt und im Rahmen einer zweiten Blutabnahme bei den Patienten in einem symptomfreien Intervall kontrolliert. Die epidemiologischen Basisdaten waren in den unterschiedlichen Gruppen vergleichbar. Medikamente stellten bei den notärztlich erfassten und behandelten Fällen über alle Schweregrade betrachtet den häufigsten Auslöser dar. Die alleinige Betrachtung der höheren Schweregrade zeigt ein inhomogenes Auslöserprofil geführt von den Nahrungsmitteln. Bezüglich der Daten zur Therapie zeigte sich, dass Adrenalin durch Notfallmediziner häufiger angewendet wird als bei den Akutbehandlungen in den Ambulanzen. Insgesamt wird Adrenalin noch nicht gemäß den Empfehlungen der nationalen und internationalen Leitlinien eingesetzt. Hinsichtlich der untersuchten Mediatoren im Blut zeigte Prostaglandin D2 die höchste Sensitivität und Spezifität. Zur Etablierung von Prostaglandin D2 als diagnostischer Marker sind weitere Untersuchungen mit größeren Kohorten notwendig. Die Untersuchungen zeigen, dass die Akutversorgung der Anaphylaxie in Deutschland noch nicht gemäß den Leitlinien erfolgt und ein Verbesserungsbedarf insbesondere im Hinblick auf die intramuskuläre Anwendung von Adrenalin besteht. Mittels sicherer und einfach anzuwendender diagnostischer Hilfsmittel, z.B. point of care test mit Prostaglandin D2, könnte die Umsetzung einer leitliniengerechten Therapie anaphylaktischer Notfälle verbessert werden

Exegetische Behandlung des Abshnitts 1 Kor. 15, 22-28

Exegetische Behandlung des Abshnitts 1 Kor. 15, 22-28 (Exegetical Treatment of Section 1 Cor. 15, 22-28

The Role of Transaction Costs and Risk Premia in the Determination of Climate Change Policy Responses

Transaction costs and risk have generally not been taken into account in assessing the Kyoto mechanisms JI, CDM and emissions trading. However, they can have a significant influence. With regard to the project-based mechanisms, the factor that most determines the influence of transaction costs on the implementation of a project is the size of the particular project. For some projects transaction costs amount up to over 1000 ?/ton C reduced, which proves the necessity of streamlining procedures, as recognised in the Marrakesh Accords. With regard to international emissions trading it will be of high importance to build on experience with past national emissions trading schemes in order to keep transaction costs low. However, international trading schemes of the type envisaged under the Kyoto Protocol are likely to have significant issues that have not been addressed in previous national experience. In addition to transaction costs, we determine country risk premia to account for the fact that projects in different states may induce different levels of risk of default or project failure. --transaction costs,risk premia,Kyoto Protocol,emissions trading,small scale projects

Pesticide Drift: A Problem in Iowa?

Pesticide drift ranks as the most frequent incident reported to the Iowa Department of Agriculture and Land Stewardship (IDALS). Pesticide drift, as defined by the U.S. Environmental Protection Agency (EPA) 40 CFR 162.3, means any movement of a pesticide during or immediately after application or use through air to a site other than the intended site of application or use

Breaking In, Breaking Out. How That First Book in Print Changed My Life, or Not

The author discussed how his first book changed the course of his life. It granted him an important role within his family, solidified his identity as an Aboriginal writer, and allowed him to tell the truth which often contradicted the portrayal of Aboriginal peoples in the media

The alkali-spinel of the Mansjö Mt.

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