Procompetitive infrastructure sector regulation and diffusion of innovation: The case of broadband networks

The paper assesses the scope for competition inducing infrastructure regulation in furthering the diffusion of innovation. The paper uses data on the adoption of broadband services comprising a global panel of 167 countries. The effects of different regulatory provisions are assessed. The result of this paper allows qualifying different elements of the regulatory debate on the consequences of access requirements, including mandatory unbundling. First, it suggests that interplatform competition is generally not leading to acceleration in broadband diffusion. Second, with respect to intra-platform competition, this has been analyzed at two different levels: full unbundling and retail competition. In the first case the competitor is investing in network infrastructure to be able to induce some degree of service differentiation. With retail competition the scope for service differentiation is much more limited and hence competition is most likely centered on price. While both lead to faster diffusion, the results consistently show that the effect from retail competition is proportionally about twice as strong compared to unbundling. Moreover, the analysis of the time profile of the effects show that this impact on diffusion first increases until the third or fourth year after introduction, but then dissipates away. Also here one can argue that retail differentiation leads to more intense price competition and therefore faster diffusion. Different robustness checks for the results are provided. --Broadband,regulation,innovation,service competition,platform competition,local loop unbundling

The diffusion of broadband telecommunications: the role of competition

This paper addresses the determinants of diffusion of broadband infrastructure by looking at the U.S. Federal States. It tries to identify in particular to what extent intra- and inter -platform competition contribute to accelerating the speed of diffusion. Panel data analysis results indicate that both types of competition significantly affect the rate of diffusion, although with different effect. Intra-platform competition seems to have a positive impact only initially on the rate of diffusion but then dissipates. For the longer term, inter -platform has a much more important role in driving the rate of diffusion. The study takes account of the impact of other variables measuring competition in the telecommunications sector as well.Broadband; Technological diffusion; Regulation and competition

The diffusion of information technology in Europe

Europe, as all modern economies, is shifting towards an information-based society, where Information Technology (IT) is dramatically modifying patterns of production and consumption and the modern way of life. Low-cost data processing and transmission technologies are leading the way not only in a technological revolution, but also in an economic and social revolution. The main drivers for these trends are technology and market liberalisation. Technological advances, in particular in microelectronics and optical fibres, have drastically reduced the cost of data processing and transmission. In parallel, reduction of trade barriers for IT equipment and the market liberalisation in key sectors adopting IT, such as telecommunications, mobilised huge amounts of private funding for the adoption of new products and services

Procompetitive infrastructure sector regulation and diffusion of innovation: The case of broadband networks

The paper assesses the scope for competition inducing infrastructure regulation in furthering the diffusion of innovation. The paper uses data on the adoption of broadband services comprising a global panel of 167 countries. The effects of different regulatory provisions are assessed. The result of this paper allows qualifying different elements of the regulatory debate on the consequences of access requirements, including mandatory unbundling. First, it suggests that interplatform competition is generally not leading to acceleration in broadband diffusion. Second, with respect to intra-platform competition, this has been analyzed at two different levels: full unbundling and retail competition. In the first case the competitor is investing in network infrastructure to be able to induce some degree of service differentiation. With retail competition the scope for service differentiation is much more limited and hence competition is most likely centered on price. While both lead to faster diffusion, the results consistently show that the effect from retail competition is proportionally about twice as strong compared to unbundling. Moreover, the analysis of the time profile of the effects show that this impact on diffusion first increases until the third or fourth year after introduction, but then dissipates away. Also here one can argue that retail differentiation leads to more intense price competition and therefore faster diffusion. Different robustness checks for the results are provided

Bioimpedance cardiography in pregnancy: A longitudinal cohort study on hemodynamic pattern and outcome

Background: Pregnancy associated cardiovascular pathologies have a significant impact on outcome for mother and child. Bioimpedance cardiography may provide additional outcome-relevant information early in pregnancy and may also be used as a predictive instrument for pregnancy-associated diseases. Methods: We performed a prospective longitudinal cohort trial in an outpatient setting and included 242 pregnant women. Cardiac output and concomitant hemodynamic data were recorded from 11th-13th week of gestation every 5th week as well as at two occasions post partum employing bioimpedance cardiography. Results: Cardiac output increased during pregnancy and peaked early in the third trimester. A higher heart rate and a decreased systemic vascular resistance were accountable for the observed changes. Women who had a pregnancy-associated disease during a previous pregnancy or developed hypertension or preeclampsia had a significantly increased cardiac output early in pregnancy. Furthermore, an effect of cardiac output on birthweight was found in healthy pregnancies and could be confirmed with multiple linear regression analysis. Conclusions: Cardiovascular adaptation during pregnancy is characterized by distinct pattern described herein. These may be altered in women at risk for preeclampsia or reduced birthweigth. The assessment of cardiac parameters by bioimpedance cardiography could be performed at low costs without additional risks

Specificity and transmission in two shallow water thiotrophic symbioses

Die ‚Domestikation‘ von chemosynthetischen mit chemoautotrophen schwefeloxidierenden Bakterien ist von Mitgliedern aus sechs eukaryoten Stämmen bekannt. Die Symbionten von meiofauna Wirtsgruppen aus subtidalen Flachwassersanden - Nematoden sowie darmlose Oligochaeten - formen eine Clade von Gammaproteobakterien. Die Ektosymbionten der Nematoden werden wahrscheinlich aus der Umwelt übertragen und ich zeige erstmals freilebende Verwandte aus küstenfernen Oberflächenwassern. Die Symbionten von Stilbonematinen wie Laxus oneistus sind in eine Schleimschichte eingebettet, die das an der Anheftung der Symbionten beteiligte Wirtslektin Mermaid enthält. Ich zeige, dass Stilbonema majum – ein mit L. oneistus gemeinsam vorkommender Stilbonematinae – von verwandten aber eigenständigen Symbionten besiedelt ist. Die Selektionsmechanismen für einen monospezifischen bakteriellen Überzug, der für Laxus oneistus und andere Stilbonematinae typisch ist, werden anhand von Mermaid-Transkripten beider Wirtsarten untersucht. Mehrere gefundene Isoformen, bei denen nur eine bis drei von 105 Aminosäuren im Zuckerbindungszentrum variieren, zeigen höhere Bindungsaktivitäten zu den Symbionten des Wirtes, bei dem sie gefunden wurden und wirken in der Anheftung und der spezifischen Selektion von Symbionten mit. Die Partner in thiotrophen Symbiosen schienen bisher nur aus zwei Klassen zu stammen – den Gamma- und Epsilonproteobakterien. Gemeinsam mit den darmlosen Oligochaeten und Nematoden findet man oft mund- und darmlose catenulide Plattwürmer der Gattung Paracatenula. Ich beschreibe die größte und häufigste Paracatenula Art aus dem Barriere Riff von Belize und zeige, dass die intrazellulären Symbionten der Paracatenula Plattwürmer eine neue Familie von thiotrophen Alphaproteobakterien darstellen. Die kongruenten Stammbäume der Wirte und Symbionten in dieser 500 Millionen Jahre alten Assoziation weisen auf eine vertikale Weitergabe Symbionten von einer Wirtsgeneration zu nächsten hin.Harnessing chemosynthetic bacteria is a recurring evolutionary strategy with six eukaryote phyla harboring chemoautotrophic sulfur-oxidizing symbionts. Meiofaunal host groups occurring in subtidal sands - nematodes and gutless oligochaetes - harbor thiotrophic Gammaproteobacteria that form a phylogenetic clade. For the nematode ectosymbionts environmental transmission is likely and I for the first time find closely related members of this clade in offshore surface seawater. The symbionts of stilbonematin species such as Laxus oneistus are embedded in host mucus containing the lectin Mermaid, which mediates symbiont attachment. I show that Stilbonema majum—another co-occurring stilbonematine nematode—is covered by related but phylogenetically distinct bacteria. The selection mechanisms that lead to single phylotypes specifically covering each host are investigated by transcriptome analyses of both hosts. I found several Mermaid isoforms that are differing in only one to three of 105 aa positions in the carbohydrate recognition domain and show higher affinities to the symbionts of the host they were found in, indicating that variation of isoforms plays a role in the attachment and specific selection of symbionts. In contrast to the broad host diversity, all thiotrophic symbionts apparently belong to two classes– the Gamma- and Epsilonproteobacteria. The mouthless catenulid flatworm genus Paracatenula co-occurs with nematode and gutless oligochaete hosts. I describe the largest and most abundant species from the Belize Barrier reef and show that the intracellular endosymbionts of all studied species form a novel clade of thiotrophic Alphaproteobacteria. In this ancient association host and symbiont phylogenies match indicating vertical transmission of the symbionts

Growth of amorphous domains in precursor derived Si-C-N-Ceramics studied with small angle X-ray scattering

Amorphous precursor derived ceramics with the composition Si26C41N33 were isothermally annealed at 1500 °C for 5 minutes up to 190 minutes. Two series of measurements were carried out: one at a nitrogen partial pressure of 1 bar and one at a nitrogen partial pressure of 1 mbar. Small angle X-ray scattering was used to determine the diameter of the amorphous domains. The Guinier radius was found to vary from 9.5 Å to 13 Å irrespective of the partial pressure of nitrogen. This finding is quite surprising since crystallization of this material strongly depends on the partial pressure of nitrogen

Doubling of marine dinitrogen-fixation rates based on direct measurements

Biological dinitrogen fixation provides the largest input of nitrogen to the oceans, therefore exerting important control on the ocean’s nitrogen inventory and primary productivity. Nitrogen-isotope data fromocean sediments suggest that the marine-nitrogen inventory has been balanced for the past 3,000 years (ref. 4). Producing a balanced marine-nitrogenbudget based on direct measurements has proved difficult, however, with nitrogen loss exceeding the gain from dinitrogen fixation by approximately 200 TgNyr-1 (refs 5, 6). Here we present data from the Atlantic Ocean and show that the most widely used method of measuring oceanic N2-fixation rates underestimates the contribution of N2-fixing microorganisms (diazotrophs) relative to a newly developed method. Using molecular techniques to quantify the abundance of specific clades of diazotrophs in parallel with rates of 15N2 incorporation into particulate organic matter, we suggest that the difference between N2-fixation rates measured with the established method and those measured with the new method8 can be related to the composition of the diazotrophic community. Our data show that in areas dominated by Trichodesmium, the established method underestimatesN2-fixation rates by an averageof 62%. We also find that the newly developed method yields N2-fixation rates more than six times higher than those from the established method when unicellular, symbiotic cyanobacteria and c-proteobacteria dominate the diazotrophic community. On the basis of average areal rates measured over the Atlantic Ocean, we calculated basin-wide N2-fixation rates of 14+/-1TgNyr-1 and 24+/-1TgNyr-1 for the established and new methods, respectively. If our findings can be extrapolated to other ocean basins, this suggests that the global marine N2-fixation rate derived from direct measurements may increase from 103+/-8TgNyr-1 to 177+/-8TgNyr-1, and that the contribution of N2 fixers other than Trichodesmium is much more significant than was previously thought

Secure full-duplex device-to-device communication

This paper considers full-duplex (FD) device-to-device (D2D) communications in a downlink MISO cellular system in the presence of multiple eavesdroppers. The D2D pair communicate sharing the same frequency band allocated to the cellular users (CUs). Since the D2D users share the same frequency as the CUs, both the base station (BS) and D2D transmissions interfere each other. In addition, due to limited processing capability, D2D users are susceptible to external attacks. Our aim is to design optimal beamforming and power control mechanism to guarantee secure communication while delivering the required quality-of-service (QoS) for the D2D link. In order to improve security, artificial noise (AN) is transmitted by the BS. We design robust beamforming for secure message as well as the AN in the worst-case sense for minimizing total transmit power with imperfect channel state information (CSI) of all links available at the BS. The problem is strictly non-convex with infinitely many constraints. By discovering the hidden convexity of the problem, we derive a rank-one optimal solution for the power minimization problem.</p