Universal mobile telephone standard (UMTS) licensing : recent European experience and the South African case by Nicolas Theopold.

Bibliography: leaves 62-64.The telecommunications industry was long regarded to be one of "natural monopoly". Technological development has, however, changed the situation in the industry fundamentally: with the introduction of digital wireless telephony (also called "GSM " or "second generation (2G)), competition could effectively be introduced into the industry, as the new networks rely on antennas instead of fixed cable networks. This made it possible, and in the presence of large numbers of subscribers necessary, to build multiple mobile telephone networks in one country

Estimation of the Jump Activity Index in the Presence of Random Observation Times

This work studies the estimation of the \textit{jump activity index} of Itô semimartingales in a setting of high frequency observations with a fixed time horizon and random observation times.\\ We give a quick overview over the underlying theory and briefly review already existing literature connected to the estimation of \textit{jump activity index} in various settings.\\ We then prove a central limit theorem based on the \textit{empirical characteristic function} whose value is in our case codetermined by the (possibly unknown) structure of the underlying observation scheme. To bypass this problem we employ an approach, that is new to existing literature, using a Taylor expansion of the natural logarithm and the exponential function to develop a consistent estimator for the \textit{jump activity index}. Yet again, the connected central limit theorem (CLT) depends on the setting of the observation scheme and is therefore not directly applicable in most situations. Hence, we develop a further CLT that works without any prior knowledge of the underlying structures

Bestimmung des Temperaturprofils der Troposphäre mit einem Zwei-Frequenz-LIDAR

Die Bestimmung des vertikalen Profils der troposphärischen Temperatur mit einem djfferentiel- len Absorption-LIDAR (DIAL) beruht auf der temperaturabhängigen Absorption spektral schmal- bandigen, gepulsten Laserlichtes durch Sauerstoff in der Atmosphäre. Die Fehleranalyse zeigt zum einen die hohen Anforderungen, die von dem Lasersystem zu erfüllen sind. Darüber hinaus macht sie deutlich, daß die Vernachlässigung der Rayleigh-Brillouin-Streuung für realistische atmosphärische Situationen zu einem Fehler von bis zu 10K in der Temperaturb estimmung fiihren kamt. Der Auf- bau und die für eine DIAL "Messung unzureichenden Eigenschaften eines Lasersystems auf der Basis eines Dauerstrich Fa.rbstofil-Ringlasers mit a.nscl1ıließender Impulsverst ärkung werden dargelegt. Die Messungen mit einem DIAL-System, das aus zwei durch Excimer-Laser gepumpten Farbstoff-Lasern besteht, bestätigen das Ergebnis der theoretischen Analyse. Temperaturprofile der planetarischen Grenzschicht konnten mit einer zeitlichen Auflösung von einer halben Stunde und einer räumlichen Auflösung von 82.5m bestiımnt werden. Dabei betrug der absolute Temperaturfehler 5K und der Fehler des Temperaturgradienten 0.5K/100m

Influence of trabecular microstructure and cortical index on the complexity of proximal humeral fractures

Objectives: Poor bone quality increases the susceptibility to fractures of the proximal humerus. It is unclear whether local trabecular and cortical measures influence the severity of fracture patterns. The goal of this study was to assess parameters of trabecular and cortical bone properties and to compare these parameters with the severity of fractures and biomechanical testing. Methods: Twenty patients with displaced proximal humeral fractures planned for osteosynthesis were included. Fractures were classified as either 2-part fractures or complex fractures. Bone after core drilling was harvested during surgery from the humeral head in each patient. Twenty bone cores obtained from nonpaired cadaver humeral heads served as nonfractured controls. Micro-CT (μCT) was performed and bone volume/total volume (BV/TV), connectivity density (CD), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), and bone mineral density (BMD) were assessed. The cortical index (CI) was determined from AP plain films. Biomechanical testing was done after μCT scanning by axially loading until failure, and ultimate strength and E modulus were recorded. Results: BV/TV, BMD and CD showed moderate to strong correlations with biomechanical testing (r=0.45-0.76, all p<0.05). No significant differences were detected between the 2-part and complex fracture groups and controls regarding μCT and biomechanical parameters. CI was not significantly different between the 2-part and complex fracture groups. Conclusions: In our study population local trabecular bone structure and cortical index could not predict the severity of proximal humeral fractures in the elderly. Complex fractures do not necessarily imply lower bone quality compared to simple fracture

The bicipital groove as a landmark for reconstruction of complex proximal humeral fractures with hybrid double plate osteosynthesis: The bicipital groove as a landmark for reconstruction of complex proximalhumeral fractures with hybrid double plate osteosynthesis

Background: Complex proximal humerus fractures with metaphyseal comminution remain challenging regarding reduction and stability. In most fracture patterns the hard bone of the bicipital groove remains intact. In this case series, we describe a novel technique of hybrid double plate osteosynthesis of complex proximal humerus fractures with metaphyseal comminution. Methods: In randomly chosen shoulder specimens and synthetic bones, pilot studies for evaluation of the feasibility of the technique were performed. Between 4/2010 and 1/2012 10 patients underwent hybrid double plate osteosynthesis. Seven patients (4 male, 3 female, mean age was 50 years (range 27–73)) were available for retrospective analysis. Based on plain radiographs (anterior-posterior and axial view), the fractures were classified according to the Orthopaedic Trauma Association classification (OTA) and by descriptive means (head-split variant (HS), diaphyseal extension or comminution (DE)). Results: Follow-up radiographs demonstrated complete fracture healing in six patients and one incomplete avascular necrosis. None of the patients sustained loss of reduction. Three patients where reoperated. The medium, not adapted, Constant score was 80 Points (58–94). Patients subjective satisfaction was graded mean 3 (range: 0–6) in the visual analog scoring system (VAS). Conclusion: The technique of hybrid double plate osteosynthesis using the bicipital groove as anatomic landmark may re-establish shoulder function after complex proximal humerus fractures in two dimensions. Firstly the anatomy is restored due to a proper reduction based on intraoperative landmarks. Secondly additional support by the second plate may provide a higher stability in complex fractures with metaphyseal comminution

SWI/SNF regulates the alternative processing of a specific subset of pre-mRNAs in Drosophila melanogaster

<p>Abstract</p> <p>Background</p> <p>The SWI/SNF chromatin remodeling factors have the ability to remodel nucleosomes and play essential roles in key developmental processes. SWI/SNF complexes contain one subunit with ATPase activity, which in <it>Drosophila melanogaster </it>is called Brahma (Brm). The regulatory activities of SWI/SNF have been attributed to its influence on chromatin structure and transcription regulation, but recent observations have revealed that the levels of Brm affect the relative abundances of transcripts that are formed by alternative splicing and/or polyadenylation of the same pre-mRNA.</p> <p>Results</p> <p>We have investigated whether the function of Brm in pre-mRNA processing in <it>Drosophila melanogaster </it>is mediated by Brm alone or by the SWI/SNF complex. We have analyzed the effects of depleting individual SWI/SNF subunits on pre-mRNA processing throughout the genome, and we have identified a subset of transcripts that are affected by depletion of the SWI/SNF core subunits Brm, Snr1 or Mor. The fact that depletion of different subunits targets a subset of common transcripts suggests that the SWI/SNF complex is responsible for the effects observed on pre-mRNA processing when knocking down Brm. We have also depleted Brm in larvae and we have shown that the levels of SWI/SNF affect the pre-mRNA processing outcome <it>in vivo</it>.</p> <p>Conclusions</p> <p>We have shown that SWI/SNF can modulate alternative pre-mRNA processing, not only in cultured cells but also <it>in vivo</it>. The effect is restricted to and specific for a subset of transcripts. Our results provide novel insights into the mechanisms by which SWI/SNF regulates transcript diversity and proteomic diversity in higher eukaryotes.</p

Anti-Fibrotic Activity of an Antimicrobial Peptide in a Drosophila Model

Fibrotic lesions accompany several pathological conditions, including tumors. We show that expression of a dominant-active form of the Ras oncogene in Drosophila salivary glands (SGs) leads to redistribution of components of the basement membrane (BM) and fibrotic lesions. Similar to several types of mammalian fibrosis, the disturbed BM attracts clot components, including insect transglutaminase and phenoloxidase. SG epithelial cells show reduced apicobasal polarity accompanied by a loss of secretory activity. Both the fibrotic lesions and the reduced cell polarity are alleviated by ectopic expression of the antimicrobial peptide drosomycin (Drs), which also restores the secretory activity of the SGs. In addition to extracellular matrix components, both Drs and F-actin localize to fibrotic lesions

Innate Immunity in Fruit Flies: A Textbook Example of Genomic Recycling

Drosophila serve as a wonderful model for studying aspects of innate immunity, i.e. the physical, cellular, and molecular features that provide the first lines of defense against infections in flies and ma